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1 - Pole Shift Survival Information

1. E ignition switch reclose and the cycle repeats The next ignition systems is electrically cor nected across the points hood of the first things you 800 is a plastic device with a multitude of wires leaving the top and scatter g though it s notas complicated as circuit between the battery and the coil that the primary winding of the coil is supplied with intermittent Surges uci pointa in i quic and control the primary current and pr long contagt pdint life a capaci called a condenser when installed Distributor Function When you open around the engine in different directions it s the distributor Don A distributor has three basic function One s to open and close the low tension cm This cutaway reveals that in some gines the distributor has two functions Drive bs the comes from gegyan the cam shaft A and distributor driveshaft has an extension B that is used to drive the oil pul right Cutaway of vacuum advance mechanism showing advance and retard diaphragms m re an text Courtesy Ford Motor Co J MANIFOLD VACUUM e below CONNECTION Distributor for eight m car has ee e eight lobes on cam and shows slot RE s D APHPAGK SPRING used to index
2. MICROFICHE x e REFERENCE gt project of Volunteers i in gt mr Sac a 57 The Backyard Mechani Volume 2 j me T P Published by n bue pe wey nu of Documents DE ME ME IWON e Consumer Information Center ee s BO IOC a ad ERU us Pueblo d iot 81002 E 2 CS s E USA m B m T See cm thee P i gu ded 3 ucc i NN 1 u D tx c Same as above Muse EC S B ile c 2 207 s 1 S 09 i i C APA 2 A E n M beo E ER QUEM Mu e z E wet umm med eit rae c o tag Reprodiced by permission NEUE is rus H Live V 127 ia aan P AE Es Reproduction of this T document any MEET form is subject to the same restrictions as those of the document a z Reprinted from THE MILITARY DRIVER 4 PEE Ay Chap Chap Chap Chap Chap Chap Chap Chap Buying A Used Car Basic Tune Up ___ Final Tuning 4 Drum Brakes B Brake Hydraulic Systems 6_ Power Brakes E Carburetor Rebuild _____ Air Conditioning gnition Systems Part 1 E 10 Ignition Systems Part 2 Spark Blues
3. be required Check your the inner surfac s for wear The drums should be relatively manual for the correct drum r moval procedure using a wheel smooth scratches large enough to Catch a fingernail mean the puller Basically you simply attach the puller to the drum or drums should be taken to a shop to be turned If the drums are lugs on some cars and tighten the puller to release the drum warped or heat discolored they should be replaced 2 Check the bra ings for wear The Shoes must have at least 16 inch of linings U remaining above the metal or rivets to warrant Jeaving them in If the linings worn begin removing them by using vise grips M release the retaining cap from 7 the brake shoe retaining pins continued BACK YARD MECHANIC a TRE ee E gt ux thickness is very danou practice simply machining the inside of the most drums can be turned only once drums to a smooth surface However or twice at the most If the drums since grinding the drums down until have a sharp edge at the back of the there jis less than 60 inch of drum braking surface the drum has been turned at least onc chine shop measure the drum care fully before turning it again Most shops will give you a trade in for your old drums if you need new ones If the bral drums need turning be sure to Have the new brake
4. Sensitive electrical com x ponents like tran SBOR in breakerless ignition gt with a stator it elimi a as electrical switch ee ee ut E it around which coils of RCH 1977 don t think too many people will quibble with the statement The ef ficiency of any engine indeed its ability to operate at all is directly dependent on the ignition qual 2 ities of a small component that h has no M moving parts ithe spark plug That quote comes from Champion Spark Go and although plugs are their business and they may be a li ittie biased about them they absolut ly correct How important are spark plugs in relation to engine Performance Well 7 in atest conducted by CH ampion and Bie a certified Dy the United Stat s Auto Club gasoline mileage is as iS cars was measured and then m asured again with a change of spark plugs being the only modification the installation of new plugs resulted in mileage in crease of 4 92 at 35 mph and a 3 44 increase in normal varying Speed situation Just a plug change also resulted in a 38 16 improvement in HC emis z sions A complete tune up yielded a E 66 37 improvement in HC emissions E IBN an increase of 14 45 in mileage bu at35 mp
5. Your car usually lets you when its brakes need help by not stop ping like it should by giving you less and less brake pedal to work with and sometimes by issuing noisy warn ings when yon hit the brakes But its aa continued The only real PEEN is me way the drums come off The Backyard Mechan ic Jan 74 DRIVER covers front drum removal and repacking of front wheel bearings a job you ll want to do when you reline the brakes Backing Plate Adjusting 6 or s Bottom Return Spring s M M S e 4 j Shoe Retaining Spring DN aid Automatic Adjuster pw Adjusting Star Wheel M continued PEN BACK YARD MECHANIC 2 _not a very safe nor economical idea to wait until the brakes are this far to replace the linings In most cases letting the linings wear extra thin causes damage to the brake drum which could have been avoided or made less costly by timely replace ment of the linings The best and only certain way to be sure of the condition of drum brakes is to regularly pull the drums and check the linings for thickness The brake shoes should be replaced when the linings get down to less than V amp inch above the metal on bonded linings or above the rivets and rivet s ES The brake adjustment often has to be backed off to re move each drum Locate the access
6. ed by in ferior braking and or an illuminated warning light you might discover a leaky mgster cylinder If the unit is leaking anywhere but the brake line connections it should he rebuilt Or M placed REBUILD ees Rebuilding a master cylitider is not at all the complicated job many people ie think Even with today s dual master cylinders which have about twice as many parts as the old single units re puilding is just a matter of removing the old parts and sticking in the new ones that come with the rebuild kit We won t go through the procedure here but a service manual as well as the rebuild kit give step by step instructions How ever we will offer a few tips you might not pick up from the instructions a few master cylinders are best replaced with a factory rebuilt unit master cylinder on your car is rebuild able most are The first step in remov ing the unit 1s TORO the 3 A manual should specify f the A E Check all brake line connections to be sure they re tight and not iere Trace the lines from the wheels to the master cylinder looking for leaks Flexible type cannectors are es pecially vulnerable to deterioration and damage inspect them extra carefully push rod at the brake pedal However on power brake equipped cars the push rod generally activates the power assist and t
7. actly how and where all of the link ages and vacuum lines attach It s generally a good idea to take some polaroid shots or make some sketches to be sure you know how everything part a you remove it to help preven any mixup fe After everything AS disconne ted from the carb simply remove the nuts that hold the carb to the manifold and lift the carb off and place it on a clean working surface Place a wad ded up rag in the manifold opening to prevent any foreign debris from getting inside the engine goes back on You can also label m lines are carefully diacannected d next thing you want to doi is carefully remove the top of the carb the pin as shown in the picture Gent ly shake the float near your ear if you hear sloshing the float must be he job a lot easier thoroughly __ replaced Plastic floats sometimes get soaked with gasoline and become too heavy Check float by squeezing it lightly If the float is A set it aside and you can go on 2 Another important before continue dismantling the carb are the special spring and ball assemblies that are used as metering Systems in most carbs Note exactly where and how these assemblies fit and be careful not to lose any of these small parts since they rarely sup plied in the rebuild kits After check ing out these special parts conti
8. 4c zu g Re b Hobby Shop Price About 8 95 i Downtown Price About 16 95 Is your labor worth 8 per hour nyone who s ever been in the military has probably heard the term preventive main tenance It doesn t matter whether you re a dental technician an aircraft crew chief or a vehicle control officer preventive maintenance is a concept you hear about and work with coritin ually eyen has monthly 64 page magazine called PS The Preventive Maint nance Monthly Why all the emphasis on PM Be cause over and over again it has been proved that it works E Preventive maintenance in the form of a grease job and an oil and oil filter change is probably the best way to prolong the life of your vehicle s power plant and help insure that the engine won t ER out to lunch when you need it m st Why Change Oil like dd other things eventually wears out The addi tion of aftermarket oil supplements may replenish some of the original chemical components but they won t remove the accumulated acid ash moisture or other contaminants that build up in motor oil over a pue ot time The oil filter can remove only SO smuch of the accumulated junk before it too fails to function properly Why change chassis lubricants like you do oil For tfe same reasons J grease wears out
9. ASSEMBLY s x ee ze shows simplicity of design TU ems MERN i Y Us LET RALIS TOOTH MUST BE PERFECTLY Armature for Ford system has two indexing grooves Armature cannot be installed back I mon wards or upside down but indexing roll pin Do Nr must be installed or armature will shift posi ear tions on distributor shaft a ES E Exploded view of Ford Dura Spark distributor E the backyard mechanic j continued k 7 grease either Dow 111 or GE CG627 sis required wherever insulator areas interface connect with the distributor cap coil or plugs This silicone grease is necessary to prevent high voltage runoff DN Chevy HEI The Chevrolet High Energy Ignition was introduced in January 1974 and was used primarily on their high performance models It is similar to the Ford breakerless and other no point systems in that the contact points are eliminated vand high voltage is triggered by an electronic signal not by the makingParid breaking of con ventional points x The HEI system consists of a com pletely new and different distributor assembly that combines all the ignition components into one solid state elec tronic unit The distributor housing en closes the vacuutn and centrifugal ad PR EIU vance units electroric module pickup coil and pole piece kn
10. BUMPER PRIMARY i YN SECONDARY 2 SPRING AT CUP FITTING PISTON x O OUTLET CHECK nug LOCKWASHER TP E eg 1 at 2 F PRIMARY PISTON ASSEMBLY i Ps f SPRING RETURN 7 RETAINER RETURN SPRING PRIMARY BRAKE QQ SYSTEM OUTLET MASTER CYLINDER RETAINER CUP PROTECTOR But if the pedal sink there is a hydraulic leak RETURN _ e c A OUTLET PISTON STOP e ASSEMBLY b E ss co Fig 2 MASTER CYLINDER DISASSEMBLY i reassembly note order in which yours come out and slide other parts out Obviously dual master has many more parts For proper pom j To disa semble master cylinder pull rubber boot and pushrod out remove snap ring Check the hydraulic system by depress ing the brake pedal and holding it firmly If the pedal stays up the system is okay s slowly to the floor Fig 3 BASIC BRAKE BLEEDING 1 Clean the bleed screw at each wheel 2 Attach a small rubber hose to one of the bleed screws and place the end in a container of brake fluid 3 Top up the master cylinder with brake fluid Check often during bleeding Pump up the brake pedal and hold 4 Open the bleed screw about one quarter turn press the brake pedal to the floor close the bleed screw and slowly release the pedal C
11. You should be able to check brake lines without raising the vehicle Af vou don t mind grubbirig on your back But if you raise the stands or ramps to make the inspection easier RJ fid doubly sure the supports are lv secured and the vehicle is chocked And of course don t get any further un der the vehicle than necessary under any longer than vou have to or stay a If the brake line connections at the wheel are tight check the back side of the tire and backing plate very carefully Leaking wheel cylinders generally leave Y telltale oe of OE fluid here these The flexible hoses are subject to de tefioration and should be replaced if the show any signs of leaking are damaged or even feel gummy Because metal lines tougher many newer cars have done away with the flexible a Generally I know 4 yu connectors and use one pigce metal brake lines fluid leakss trace the length of metal line from each wheel to the master cylinder The main lines should be in spected for leaking connections dents cylinder f Cm t MASTER CYLINDER The the hydraulic system It is located in the engine compartment opposite the driver and connected to the brake pedal by a special rod The master eylinder initiates braking when the br
12. market on the car you re interested in But with the price of used cars sky Your base credit union should be glad T rocketing you re going to make pretty to give you the blue book price Veg T healthy investment in a used car in any car but the true going price is most fact you may spend about as much as accurately reflected in newspaper ads LE you d originally planned to drop So get a feel for price and availability new car So now more than ever before your car by scanning the papers its important to shop carefully and get before you re ready to buy good deal on a used car you really When you re checking out the ads want oc 5 you ll probably see cars you re inter When you re BEL a new car you ested in listed by new car dealers used really don t have to worry too much lots and private owners So the ay _about whether the car is safe and reli logical question is where to buy Well 4 i able But with any used car it s impor each of the three possibilities has vari p Casas _ tant to make sure th car is in top ous advantages and disadvantages But x SEI l condition for maximum driving safety before we go any further we want to and pleasure So with this article we ll say one thing DIAGNOSTICS offer some basic tips about buying a used car that should help you oer al of DIAGNOSTIC ERNE NE the car you re payin
13. 12 Grease Oil And Filter Change 3 lt EE THE TRAFFIC SAFETY MAGAZINE FOR THE ie MILITARY DRIVER aufo maintenance series designed fo help the novice working at home as well as to provide a few reminders for the experienced hobby shop mechanic X Prepared and written 8841 Don Holt al i CT tow op fd t he Air Force s DRIVER Magazine Staff AFISC SEDD Norton AFB CA 92409 quiet aR sng Some Basic Tips on Selecting 7 D l x x a Safe and Sound Used Si For s le by the ARR s of Documents U S Government Printing Office Washington D C 20402 2 Stock 008 070 PONERET Catalog No D 301 72 A M46 V 2 l kd M a ie ux gt p Cee you were thinking about a new hanging onto this car for a few years Do vuU mo o car this fall you probably ran right 7 you might as well get a car you down to checkout Detroit s latest like pa CT Wem deno offerings And unless you re still x cold from the shock of seeing MARKET ihe price stickers you mighb have After evaluating your wants needs B decided you re really interested in and financial status get a feel for the WEN late model used car after all
14. Open the bleed screw at one rear brakes have an assistant press the brake pedal slowly until the light goes out Quickly close the bleed screw 3 Check brake fluid level and brake pedal height and firmness Road test the car C To centralize the valve on 1967 1970 drum and disc and 1971 1973 drum only American Motors cars 1 Before repairing bleeding the brakes disconnect the itch terminal switch termi nal contact plunger spring and E da plunger with contact I 12 If the light had come on and actuated the valve spring pressure may hold the EEE To E the E Fig 1 d e apply a small amount of brake pedal E pressure 3 NOTE Location of the leak can be determined by the position of the plunger in its bore The top of the plunger will lean to the side front or rear which has the low pressure 3 Make the repair and Bleed the brakes Install the spring and plunger in the valve with the contact down 4 Instali the nylon terminal nd r connect the warning light wire Xo the terminal 5 Replace the valve ass mbly df any fluid leaks from the center terminal opening while removing the terminal IMPORTANT The switch assembly is non serviceable replace if faulty Most 1972 and newer cars have special units that combine the metering propor tioning and brake failure warning valves int
15. VU A continued T 3 m Adjusting access window on GM distributor ta the distribtuor continued THE BACKYARD MECHANI cC 9 7 7 them finger tight before tightening them with a socket or torque wrench POINTS Afterchanging all the plugs you re ready to get into the distributor In if you work carefully tributor to work on it you can avoid a lot of potential problems by leaving it in place and simply being careful The most important thing when re placing the ignition parts is not losing the small hold down Screws espe cially not dropping them down into drivers are a big help for this job type cap and turn the screw heads in the cap When you re ready to Teplace points thefirst thing you ll need to do is remove the distributor cap cial locking catch To remove this simply luse scr wdriver until the locks release see photo by external clips that can be POPPE off with a screwdriver Check the removed very fully for cracks or excessive carbon on the inside contacts If eitherate found a new cap should be _instaHed When installing the new cap make an accurate drawing 6f where the plug wires fit into the you can install the new wires properly If the wires do get crossed and the en gine won t start or runs poorly service manual has a diagrein of ho
16. ing The higher currents developed dur ing cranking are not sufficient to cause point deterioration because of the short periods of time spent cranking cranking causes a lower primary cur r ht so the resistor bypass feature is an x offsetting feature Bypassing re Sistor with the engine operating will cause rapid deterioration and failure of the points I The Final Link The final link in the ignition chain is the spark plug This device which appears So Sifmple ex ternally is actually So complicated in its operation and relation to engine per formance that we re going to do ia sep arate BYM for spark plugs p Next month we l cover BEIS HEIs EDs and X sistors nd we ll even explain what all those imtials stand for of Action Auto Parts San Bernardino CA for providing the distributors photo eft With distributor cap removed the first thing you see is the rotor Rotor contact end can become pitted with Qanqa use and contact Spring piece on top may lose tension Rotor is a slip fit on distributor Shaft and will have an internal projection to match a slot on distributor drive shaft to insure correct orientation right Distributor cap should be checked occasionally for cracks and contact wear A bad dis tributor drive shaft can wobble and allow the rotor to impact the metal contact points imbedded in the cap The center grape contact but ton may
17. lose its spring loading and not make sufficient contact with the rotor to insure complete ignition left If for Some reason you find it necessary to remove gt the distributor first make an illustration like this It shows the position of the rotor felative to some reference point like the vacuum advance Since the distributor drives uses helical instead of straight tut gears the shaft will rotate as it s removed Unless you know the correct final rotor orientation your drawing you probably won t get the distributor back in correctly right This is about the point where the drive gears will begin to mesh As you go further in shaft will turn IF you haven t made your drawing you won t know where the rotor is supposed to be oriented Also in some Cars you won t be able to get the distrib tor all the way in because the drive shaft extension won t mate with ihe oil pump shaft correctly Like we said make that drawing before yoy pull that SBR m ok i z N i Sore th One component change Ford Dura Spark control module shows how spade type male connectors and keyed connector housings are constructed i to minimize assembly errors right GM HEI distributor cap is much changed from conventional cap Large well in cap ere BBS icnition coil goes and projection on left is electrical connector Pen points to new design of s
18. tween alternations of cur rent the zero signal decreases In this way the control module knows when to open and Close th the e pri miary Circuit Fans Ford advises that the 77 Dura Spark system uses coil current reg lator provide a stall shut down feature When the engine stalls the module shuts off and locks Unless the igni tion switch is first turned to the start position mod ule will not provide any spark E Readers should also note that because of the increased high voltage new spark plug wiring svs tems are being used The most apparent difference isthe larger diameter of the plug wires up from 7 mm t0 8 mm Also Silicone pes continued VACUUM UNIT HOUSING i WASHER GEAR W CONNECTOR STATOR i ALIGNED WITH STATOR 1 Static timing position of stator for eight cylinder engine Air gap between stator and armature must be adjusted when new stator is installed Adjust air gap only with non magnetic feeler gauge brass or plastic ROLL CD mere RETAINING CLIP MAGNETIC PICKUP ASSEMBLY es MV hace ASSEMBLY HE X SYSTEM on GROUND vacuum MZ EN CR ADVANCE UU um LINK HARNESS CONNECTION T5 PLATE ASSEMBLY i WIRE RETAINER SLEEVE AND PLATE
19. un f adjuster and parking brake gs YOU may have id an The shoes to move out of place Finally when you pick up the new brake shoes be sure to grab a couple of wheel cylinder repair kits You may not need to rebuild the wheel cylinders but you might as well have the kits handy just in case this will be discussed later The shop should also be glad to take back the kits if you don t use them When you ve picked up the new brake shoes and had the drums turn ed if necessary you can finish the brake job in a matter of an hour or so The rest of the job is a process as illustrated in the accom panying pictures Just work carefully and slowly following the procedures recommended in your manual Be sure to work on one wheel at a time SO use the properly assembled brake as a quick ref rerice When everything is back together yQu can repeat the other wheel With both wheels completed have albuddy operate the brake pedal while you spin both drums by hand to be s re the brakes Work If they both check out you can button everything up and go for cautious test drive If there aren t any unusual noises and the braking action is good all set Go easy on the new linings for the first couple hundred miles to give them a chance to wear in especially if they haven t
20. Sight Glass A C Thermostat Switch Typical A C C mponentloc amp tlon Ford ers we x vem adjust idle speed up set the idle cam on a higher notch Locate the sight glass and remove any covers and clean it with a rag if the receiver is near the fan use caution to insure the rag doesn t get caught in the fan Have someone set alc blower and controls at max and watch the sight glass The glass should foam ur and then become clear Unless the out side temperature is less than 70 de grees the glass should become com pletely clear within a t w minutes A few bubbles will be present at the cooler temperatures even if the system is operating correctly If a few bubbles appear at warmer temperatures it indi Cates the system is slightly low on R 12 the 91 amp remains completely clear from startup the system probably iS foams and then turns Clear go on to Pa be hot so watch it The line should be warm along its entire length A drop in temperature indicates a clog at the point of the temperature drop If the drop 08curs at the receiver the receiver will have to be replaced because itis clogged with moisture or dirt lt The main suction and discharge lines atthe compressor should show a definite difference in temperature one hot and one cold If they feel about the same and the sight glass doesn t foam even
21. and The new systems are specifically Dictionary of Electrical Abbrevia designed for each car to work with other components of the emission con tigers edited by D H Polson Press rol Sram and those emission sys Ue trol xc BEL Breakene s elec ong system ook A current limiting element A bali lastresistor is a resistor used to limit the current and keep it under con tronic ignition Has no 5 HEI High energy Capacitive dis d A points but points carry _ Reluctor The armature 8 less current than Ketter 2 systems In conjunction x uf nates contact points SCR Silicon a rectifier A solid state device similar to i transistor in that it E vides current path consisting of a solid _ material silicon d Stator Replaces con m tact points when used in conjunction with re ductor Usually consists ofa magnet imbedded EO a T K plastic but may also _ be light sensitive gt device when used inan LED light emitting TR diode triggered 19012 x E E small dough mut shaped iron core lt Wire are wound similar Heat Sink A device ee used to absorb heat pro duced by electrical com ponents By releasing SE equipment heat to at mosphere sink prevents overheating of heat
22. best on brroded terminals gt 3 The in line filter either clamps into the fuel Jine or on most Ford products it screws into the carb with the fuel line clamped to the other end The new filter can be clamped into place exactly as the olt filter came out misson Systems Emission sys tems should be properly maintained to keep emissions down and per formance up The Backyard Me Chanic Parts VII and VIII in the _ July and August DRIVERs cover emission system checks But during a tuneup your main concerns should be the PCV System and the heat riser and or thermostatic air clean ORF d Dt An easy way to check the PCV system is to place a sheet of paper over the oil filler neck If the paper is pulled in by suction the system is operating Even if the system is operating this is the perfect time to install a new PCV valve the valve should be replaced every 10 000 miles or so To replace the valve simply locate it in the rocker oe z h z I i l A cover or intake manifold Pull the old valve out of its rubber grom met and insert the new valve being sure it is properly seated in the grommet The Peat riser is a simple valve that controls heating of the intake manifold by exhaust gases If the valve sticks it causes all kinds of The gas filt r fits inside the carb on most GM produc
23. ders for leaks by pulling back on the rubber cap Any fluid inside the cylin der means the unit will have to be rebuilt or re placed The cylinder can be rebuilt by simply installing the new parts included in a rebuilt kit Easy to follow in structions come with the I kit However wheel cylin a ders can only be rebuilt if the bores are in good con dition Light scratches can be cleaned with crocus cloth and a rag soaked with clean brake fluid But deep gouges call fora new cylin f der If the is rebuilt or replaced you will need to bleed the brake system to remove any air that entered when the cyl inder was opened This will be covered next month z lf the wheel cylinder is not leaking or after it is rebuilt tie cord around the cylinder pistons to prevent them from popping off accident ally and leaking in air Then use a small broom and an alcohol soaked rag to thor oughly clean the Mee as sembly After cleaning the assembly and drum with alcoho as the old ones came out Be sure to hook up t roperly Make sure there isn t any brake nd double checic the assem th tb assembled brake he adjuster wheel until the drum will just ralize the shoes by hand to get the drum vithout the drum to hald them d or oil on new linings or the brake tightens
24. iirider whichever settings are appro prate For a four ord engine men uct vi the cael point i snap Simply insert the all wrench into the adjusting gut nd turn if until the dwell is riali on If the dwell is high turn the clock wise to open the points Afthe dwell is low so counter clockwise to close the pots i t Adjusting the dwell ona non G M distributor be a pain since it s more of a trial and error procedure pleas of adjusting the points tion plate the engine compartment rect dwell is obtained However with helper you can cut out a lot of Remove the distributor cap and rotor and have your helper crank E 2 g get a reading on the meter Then make the appropriate paint gap ad pgs T En justmenit high readihe wider gap H low reading ni arrowe s gap and have i him So youcan lt check the ncw setting procedure until reading Eentinuc this getan acceptable Doing this prevents having jd continued i ue continued THE BACKYARD MECHANIC to adjust the points reinstall the rotor and cap and start the engine after each adjustment to check the dwell You can also work this system by yourself with a remote starter switch DWELL HOLD After getting the dwell right on you should perform a dwell hold test to che
25. the service stickers just to be sure the mileage figure is correct Also if you re buying from a lot you might be able to get the previous owner s name off the s lube stick rs or perhaps you can find his name on an old creg dit card slip somewhere in the car In any case if you can find the previous owner s name you can give him a ring and ask him about the car Inside the car check all of the equip ment nd accessories to be sure they work Items like the turn signals heater and defroster are a must of cours amp 4 Also make sure the windows nd doors open and close correctly If the interior shows excessive wear you Can assume the car has had a lot of miles or at least hard ones sure to check the brake hydraulic holding down firmly on the Ils pedal for at least thirty seconds if the pedal stays firm the hydraulic system be Tre E is okay On a manual transmission car continued near ehd ook in 4 trunk for operational Jacke flat d spare check to see that the clutch has tham 1 inch of free play basic way to check the clutch is to put the car in gear apply the emergency brake engine running and release the cluteh if the clutch is okay the engine will stall when the clutch is released Make sure you make this test in an open area with no one in front ofthe car TEST DRIVE After checking out the inside of t
26. which in turn creates the voltage spikes mentioned earlier With every breaker point cam revolution one spark will be produced for each cylinder remember though since each cylinder fires at every other crankshaft revolution in a four stroke e Speed The distribular shaft and weight base assembly is fitted with bearings nd rotates inside the distributor shell or housing Centrifugal advance weights are pivoted on studs in the weight base or on the bottom of the breaker plate Vand are free t move away from the shaft and work against calibrated ad vance springs connected to the breaker cam assembly The breaker cam as sembly slip fits the top of the shaft and rotates withthe shaft being driven by the weight springs activated by the advance weights Outward movemerit of the weig hts ad vances the cam assembly in relation to the shaft as engine Sp ed increases i amp the more engine speed the more the spark is advanced and therefore provides a means for the spark to arriv at the spark plug earlier than at speed Each engine model requires an individual spark advance curve to insure delivery of the spark at the right 70 continued instant kai maximum power at all en gihe speeds An improvement in fuel economy on engines operating under part throttle conditions is realized by supplyihg ad ditional spark advance Vacuum a
27. 45 to a frammis located Ne receiver or firewall and alec susasoununapgnsaq E assum the frammis is a low etha ant protection switch If you have voltage on anm com ignition side of the but not 12 is low continued continued Kar cs THE BACKYARD MECHANIC Mc a voltage is is T at the compressor x side check wiring and connections back to the ignition switch Check for a blown fuse in the fuse block or an inopera tive thermostat usually located pening the ve control knob C Inspect condenser and fan Check condenser for bent or damaged fins FOD Straighten the fins as necessary but be careful not to damage any of the tubes Check the fan for bent blades or wobbling and insure that it is not slipping to function badly QUT D Leaks R 12 m show up as oily film or substance on the various components because compressor oil is carried around the entire system along with the refrigerant Look for oily spots on hoses and lines and at joints A small yamount on the front of the poea cee is normal gt due to worn belts Remember that cooling system malfunctions can cause the alc REAR HALF DUCT ARM ts BLOWER M MOTOR X UE We FAN ASSEMBLY Xx EVAPORATOR COOL AIR NOTE a c is low on R n and wish to recharge it yourself with
28. EDGE SHARP EDGE left After sand blasting regapping and filing plug i is alios as B od as new center New plug right The typical used plug i crusted with deposits and will be light Pm to grey in color with minimum electrode erosion AW NE EN DIM NS CHER SEHET MONE V E RET LE T s s 3 A RS g E y left fouling indicates clogged oil return passages badder rings or clogged PCV Hotter plug may relieve symptoms but there wil still be a mechanical problem in the engine center Carbon fouled plug indicates rich mixture weak ignition clogged air cleaner high floa level or Sticky carb float right Center electrode is too worn to alow regapping Time fornew plugs m p s i ovs M M I i 2 Chart 1 ROM Set a amp Plug Thread Iron Heads Aluminurn Heads rod Y AE arie 14 Ibs ft e ABIDE Ee e _ i uc f ku c BO bs dt 5 28 Ibs ft gt 18mm 34168 SB SS SE 7 8 in 37 Ibs ft 35 lbs ft i Since each engine fidi different temperature characteristics each en gine must use plugs of a specific heat a If performance parameters are gt radically changed from those originally shell hot envisioned for the engine theh the plug heat range must B altered The hottest
29. F z A a iar 3 ioe E os ics equipped car nianudlly reasons sc re E distance you just have to Pur SYSTEM COMPLICATED f componente that seem e I a aren t the Power brake booster peke special to the job there ain t n way you re going ab to rebuild or repair a power assist e d e M unit does not wark the c T p E i font Wa uN l valve jew have power brake e ae brake pedal about a dozen times to be sure and exhaust all vacuum from the system Step on the brake pedal and hold it down firmly Start the qq engine If the vacuum whit is work ing the brake pedal will move for ward slightly as the engine starts If the pedal stays hard and does not move the vacuum unit is not func tioning The first thing to do if the power unit is not working is to make sure it is getting vacuum from the engine Pull the vacuum hose loose from the power unit see picture and place your thumb over the hose There should be plenty of suction at the end of the hose with the engine idling If the vacuum is weak check the hose very carefully for leaks ot kinks Install a new hose if the old one is defective If the hose is okay and there is insufficient vacuum check for vac uum at the intake manifold Place your finger over the manifold vacuum port or attach a
30. a volt age high enough to ionize the spark plug throttle plate when the throttle is inthe gap and ignite the air fuel mixture in the idling position In this position there i is no vacuum When the throttle is partially opened 4b swings past the opening of the vacuum Intake manifold v cuum can then 55 cylinder typical coil is made of a primary winding consisting ofa few hundred n of 198 wire and ontruge MER ite N ROTOR CAM ASSEMBLY SHAFT AND WEIOHT ASSEMBLY WICK 1t E SAP DRIVE GEAR 1 GROUND SPRING cc DISTRI BUTOR RETAINING LAMP DX 1 thousands of turns of very sm ll wire These windings are assembled over a soft iron and enclosed by a soft into a one piece steel or aluminum shell ell This assembly is then fitted Saas which is then filled with oil and hermet B case is filled with hot high dielectric insulating material Coils are Sealed to prevent Strana of moisture which could cause coil failure During manufacture the coil ically sealed by a coil cap of molded 4 AS the oil X BREAKER PLATE MYLOM PAD 3 USED C CLIP NYLON SPACER WASHER HOUSING ASSEMBLY EAL BREAKER POTS Also the lowere
31. a you on the correct grades of on t00 d Te not sure what youi need 23 fen you a mutfler or onvert remove it A little duct is elim and cx watch Fy h the car is on the lift and the drain oil receptacle is in place remove the oil drain plug from the oil pan A word or two of cautionyxthe oil will be hot and so will drain pli you can bum fingertips T _ easily Also note the direction in which a hud jaws of the crescent wrench are facing cos 6 turned around it may slip ooks like she s doing it right Lindy s got plenty of light the catch pan is in place she has a rag to hold onto the drain plug if it s s too hot 10 oll is draining from the pan Ae e tb remove the oil filter This o sh ws how some eople Ves the filter will be tight a filter wrench remove it o over ut that s e backyard mechanic continued 11 The oil filter wrench usually takes the shape of a strap or chain that fits around the filter canister There is only one way that is cor for filter wrench operation If IF slips you know you have to turn it around 3 tf 2 12 wrench carefully remove the filter and let nit s wn vertically Again the oil and filter Will be hot and spilled hot oil runhing
32. at startup the R 12 charge is gone s EA Water Valve Paro E Sight glass Start th amp engine and very low and needs a charge the glass a F Line temperature Carefully feel along the tube that runs from the denser to the expansion valve It may Blower Motor Resistor HIGH PRESSURE RELIEF VALVE G Blower performance Operate the system with the blower at high speed and the temp control set at the coldest setting Engine should be at fast idle The temperature at the discharge vents will vary with the weather but most sys tems will maintain a comfortable tem perature in all but the hottest weather Above 90 degrees expect a slight r duction in cooling lf the outside temperature is normal RECEIVER DRIER INLET Ao SIGHT GLASS OUTLET LOW PRESSURE CUTOUT SWITCH 70 Receiver assembly showing sight giass If the lever is moving an air door or water valve inspect the linkage to see if it is operating properly The most com mon problem is an incorrect adjustment or a slipping adjusting screw The adjust is usually made on the clamp which holds the cable in place Adjust the cable s position so that the door or water valve will move to its fully closed or maximum position just before the tem rature control reaches it max travel and jhe a performance is st
33. circuit except wat the tran sistor is bypassed by the diode which freely passes this reverse current We then close the points and com Xu the cycle by 8 current flow in the power circuit he ignition switch and back to Ford Dura Spark In the Ford Dura Spark solid state system the conven tional breaker plate and cam assembly is replaced by a magnetic signal gen erating system which detects the dis iributor shaft position and sends elec trical pulses to a control module Ihe module switches off the flow of current to the coil primary windings inducing the a windings to build up a high voltage charge which is then directed 10 the spark piugs as in a conventional System The control module contains timing circuits which then close the primary circuit allowing it to build up a suf ficient charge that will enable the sec ondary windings to produce the high voltage required to fire the next cylinder In effect this timing action sets the dwell Remember dwell The period of time that the points in a Kettering 0 33 QNM BALLAST TACH BLOCK BLOCK 6 43 MOUNTING TRANSISTOR COIL DISTRIBUTOR Lw CONTACTS FIG 1 Ford transistorized ignition system i 46 explained ir in text f Schematic courtesy of Ford Motor Co J i System rem in closed Because of the inher
34. cleaning the carb didn t seem to help you may be in J placement Prpyiding you ve carefully checked other areas that could be causing performance problems Industry surveys show that Car owners generally blame the carb uretor for poor engine performance However about 80 per cent of the ime other problems such as a plug PCV system a leakin ifold Jorja bad valve ieat adt So thor oughly check all possible sources of rperformance problems before tearing into the carb In the case of a mal functioning carb first check to Sec j that the heat passages in the itake manifold near the base of the catb are clean These passages especially on Chevy V 8 s sometimes plug and cause carb problems Also check to b sure the gasket between the carb is tightened dowa an air leak here or at the manifold could be i d ome causing trouble But before we go one step juriher we want to emphasize strongly that rebuilding is not for every carb nor is it for every person Only a few years ago it used to be just about standard procedure to pull off the carb and rebuild it about every other tuneup Well let s face it in the last few years carburetors have got ten more complex but at the same time they ve gotten more reliable so they really don t need maj
35. deal with in this Backyard Mechanic Next time we ll pick up with some of the regu l r checks and service needed to keep i simple as they are essential While drum brake service can be a bit more involved than disc work if you study service manual and work carefully you can easily and safely do a com plete brake job at home with ordinary tools and equipment In addition you ll save nice bundle of cash Sjnee m st newer cars are equipped i with front disc brakes we ll only be i concerned with rear drum brakes ur Brake maa as and or pads for wear and replacing them when they are worn too thin your car s brake system doing its _ thing like inspecting and bleeding the hydraulic system and checking the self adjusters SIMPLE SYSTEM LUE Because brakes are ne Tundred per cent essential to driving many backyard type mechanics are leary of doing any brake system maintenance But as we discovered in The Back P yard Mechanic Part V May 73 DRIVER that dealt with disc brake Service brake Systems are about as here However the procedure for lining front drum brakes is basically the same as for rear brakes So if you have drum brakes all the way around you shouldn t have any prob lems doing a complete brake job by following the basic procedures given here and in a service manual WHEN TO RELINE
36. eventually and becomes contaminated with foreign matter just the same as oil Since both chassis and engine parts are made up almostzentirely of metal they are subject to failure caused by contaminants in the lubrication Abra sion Or the wearing away of the metal itself is one problem Another is the formation of deposits of foreign mat ter by the ey of jubri EN cant to keep surfaces clean A third problem is the failure of metal caused by the attack of acids formed by com bustion or chemical reaction acids that be defeated only by removing the contaminated lubricant How often One thing is certain you won t hurt your engine by chang ing the oil too often We at DRIVER feel that frequent changes of oil and filter are the keys to long engine life With the exception of new cars using a reputable synthetic such as Mobil 1 feel that 5000 miles is the long est your car Should go without a change In dusty areas of the country Amd while you re at it don t forget to check 3000 is about the outside limit and change if necessary the fuel and air filters transmissians have a fluid filter m check em when you PM too Power brake systems WC often have an air filter and automatic a o pre 71 cars son change em as needed and we think you ll find that the cars of toda
37. front disc E kes and rear drums We ll discuss these special devices as well as the pres sure differential warning system in next month s powerbrake installment gt 5 we we re finally going to finish off brakes in this Backyard Me chanic Last time when we dis cussed the brake hydraulic system we didn t get to the spe cial valves that are important parts of today s hydraulic sys tems briefly before wrapping up brakes u with a discussion of power brake assist units PRESSURE DIFFERENTIAL SYSTEM Soon after the auto companies ins troduced dual master cylinders help prevent brake failures they went AE ome better with brake pressure dif ferential warning systems These de vices are designed to aetivate the dashboard brake failure warning light as soon as there is a loss of fluid pressure in the hydraulic system either front or rear brakes Basically the warning system is a piston assembly with the brake fail ure light switch attached to it Fluid from the front and rear brake lines runs through the assembly and Holds the piston centralized in its bore be cause there is equal pressure from threatened last month So we ll cover these devices each line If a leak develops in either system front or rear however the fluid pressure decreases and the pis ton moves off center triggering the warning light This system
38. gas mileage Well unfortunately there aren t any magic tricks or gadgets that will sub stantially increase fuel economy The specifications So the real way to get maximum performance and gas mile age is to perform a thorough tuneup But by thorough we mean more than just slapping in points and plugs although this alone will usually im _ prove performance A good tuneup can be broken down into three major steps that be gn with an inspection of the basic systems such as the fuel and electrical systems Phase two is the actual tune up step of replacing parts And the last step is maKing the ultra important final settings and adjust ments We ll outline the basics of the first two steps here and next month we ll cover the use of tuneup equip ment for making the final adjust ments GENERAL CHECKS The first thing you should dp be fore beginning a tuneup is glance through a manual to get a good idea _of what you re going to do and what equipment and parts are needed It s usually a good idea to pick up regularly replaced parts such as fil ters when they are on sale But if you don t have replacement parts on hand your best bet is waiting un til you check things out before buy ing parts This way you won t go out and pay for parts not really needed After checking a manual the first amp tep in a
39. he of the kits on the market please consider either having it done or asking your installation hobby shop for assistance No matter what the labels on the kits say you should have a gauge kit a leak checker and a purge kit to do the job right By the time you ve purchased two or three tittle cans of R 12 and the hdse kit you re only about three dollars away Illustrations courtesy of Mitchell Manuals Inc cee e oP EVAPORATOR ASSEMBLY T pet SCREW 4 us SCREW 8 FRONT HALF OF DUCT x SCREW 2 2 U CIR RESISTOR 7 ASSEMBLY GASKET BODY SEALER Evaporator assembly I location i General Motors AD P mS e a 7 f Blower aio and fan operation if you determine that your shop BLOWER SWITCH from the price most a c servicemen charg to do it An added benefit of having a pro do itis that he can evacuate and dry your system while he s at it for little or no extra coin If you still want to do it yourself check with the hobby most of them have at least the gauge Kits Trying to put two pounds of R 12 in a system that needs only 9 ounces cannot only be frustrating but possibly dang rous CONDITIONER HEATER ASSEMBLY SK PLENUM BLOWER AND 5 VALVE ASSEMBLY m L 2 STAMPED NUT 5 E T Trans Dipstick Restrictor Motor Expaniion Valve amp
40. is great if you develop a hydraulic leak and the light lets you know about it But as some of you may have discovered other things can trigger the warning light In many cases opening and bleeding the un System activates the light And with some cars the lights have a bad habit of coming on when the front wheels are spin balanced on the car or for no apparent reason at all shouldn t is just disconnect the light system is there for a purpose and having a disconnected light won t do you a lot of good if you do have a brake failure So it s a very good idea to know how to centralize the to turn off the light without de pist actiM ting the system In most cases The first thing some do if the warning light comes on when it i the job is easily done check man _ ual for the simple step by step pro cedures for centralizing the warning valve on your car Figure 1 also out i l amp lines the basic procedures for most cars gt EI PROPORTIONING VALVE On vehicles equipped with front disc brakes and conventional rear drums a special proportioning valve maintains correct fluid pressure be tween the front and rear brakes to provide balanced braking Although the proportioning valve rarely m l functions if unbalanced braking that s not attributable elsewhere develops the inexpensive unit should be re pla
41. of the open end If the pencil comes out wet fluid is leaking past the vacuum cylinder piston If so the unit should be replaced Fluid leaking into the engine will cause it to run poorly and enough fluid can cause sticking valves and other seri e s engine problems Before replac A power brake related check you should make when checking the brake adjustment is to make sure that the power unit is not causing the front brakes to drag With the cars front end raised and properly supported spin the brakes properly adjusted wheels Immediately start the engine ually and turn freely If not have the vacuum unit checked out by an Remove the vacuum hose that runs to the power assist at however check _ but do not touch the brake pedal The wheels should coast to a stop giad expert Figure 3 gives the procedure for checking the automatic adjusters on drum brakes 0 Leaking brake fluid can he pulled into the engine gt through the vacuum line Pull off brake booster vacuum line at the manifold connection and check the inside of the line for fluid If the line is wet the brake assist or master cylinder whichever is leak ing s seul be replaced to prevent engine damage N m The check valve is designed to let air out of the assist unit when the power brakes are operated but close when vacuum stops If the val
42. plug Fouled plug Conduative de posits may form on the ingytator surface and drain away ignition charge Oil foul E ing is the most common form of fouling and is sometimes cured by a change to a plug of a slightly hotter range _ Plug Gap Adjustment Plug gap should be set or reset only by bending the side electrode Don t exert pressure on either the center electrode or the in sulator When Measuring gap on used blugs use apin type gauge and nota feeler gauge because irregularities in the electrode surface can cause in correct readings Always gap new plugs and always regap used plugs use your tech manual to get the right gap specs don t take your buddy s word Coil Polarity If pull the plugs out of an engine and the side electrode is heavily dished or scooped opposite the center electrode chances are your Coil polarity is wrong Polarity should always be negative at the spark plug terminal because this considerably de creases voltage required for ignition Wis is because of the higher operating temperature of the center electrode if you remember your high school d physics electrons will leave the hotter surface at lower voltage Check your coil the negative lead 5 should always run from coil to the distributor on vehicles a negative ground system 4 D the with a continued Ash fouling ma
43. primary causes of timing error so be sure to keep the light at about a 45 angle and sight directly down the light The timing light will flash each time the number one cylinder fires and make the timing marks appear to stand stil pointer will align on each flash if the engine is in time If they don t line up you will have to adjust the timing by rotating the distributor To do this you first have to loosen the clamp bolt that holds the distributor in place On most older engines the bolt is amp asy to get to However On many newer engines the bolt is located be causes of timing error If the timing is off simply loosen dis E tributor lock boit and rotate distributor until the marks line up then the engine siS timed The mark and timing Before timing the engine remove the vacuum 1 advance I line at the distributor and plug it with a golf tee or a vacuum gauge Then with the engine idling aim the light carefully at the marks keeping it at about a 45 angle NGt aiming the Hen carefully i is one SES the major hind the distributor and you may need a special distributor wrench or a swivel attachment on a ratchet ex tension to get to the bolt To adjust the timing simply rotate the distributor slowly until the timing mark and pointer align Then care fully lock down the clamp bolt and double check the setting to be sure it didn t change when the distributor was tightened With the ti
44. put ting a super tune on an engine are a dwellmeter preferably 3 combination tach dwell and a timing light This a E equipment is available at your base es shop But if you re really into up the necessary equipment at a discount store for around 25 and 3 have your ownzhome tuneup Center Many stores carry special tuneup kits that contain the essential equip most of the less expensive ones come with the weak flashing neon bulb 77 g li ghtw hic ich is relatively in ccu brighter flashing power timing light is only way go as we ll explain later So if you buya complete tune up kit be sure it has a power timing E light either A C or D C power d is Gkay but the D C is handier You might also consider buying the tune we up items individually since most dis count and department stores regu larly place tuneup equipment on sale By watching the newspaper ads you Probably pick up a good quality timing light and tach dwell for about what you d pay for a kit cont ining less accurate instruments X Y DWEEL OUI m S DD engine is setting the dwell angle this is basically just da more precise measurement of the point gap reading how ong the points stay closed before opening with the en ment But while these kits are handy gine runn
45. rotor location of points _ P and condenser VACUUM ADVANCE SPRING ADVANCE DiAPHRA e d the backyard mechanic spikes of current Each spike builds up a magrietic field within the coil The dis tributor then opens its circuit so that the magnetic field will collapse and cause the coil s secondary windings to produce a high voltage surge for more info see Coils The second function is to time these portage spikes with regard to engine requirements This is accomplished by the centrifugal and or vacuum spark advance mechanisms The last function is to distribute or direct the spikes through the rotor cap and high tension wiring to the Spare plug that is ready to fire next gt typical Keltering system dis tributor consists of a housing drive tension leads form the system which shaft centrifugal advance assembly vacuum advance diaphragm and link age breaker plate assembly con enser rotor and distributor cap The distributor cap rotor and high directs the high voltage impulses to tie spark plugs in correct sequence x ee ds distributor t rotates The breaker plate assembly contains the breaker lever the contact support and the condenser When the point cam attached to the distributor drive shaft _ rotates each cam lobe contacts the breaker lever rubbing block and causes the points to separate
46. screw s at the base of the carb one barrel carbs have one mix ture screw while two and four barrel carbs have two mixture screws Turn the screw in until the idle roughens then turn the screw out slowly until the highest possible tach reading is obtained If there are two idle screws repeat the Procedure on the second screw You may need to turn the idle speed down before the Sec when the first mixture ls reset With the mixture set simply set the idle to the correct speed following the procedure shown in the manual Once again be sure the engine is fully warmed and double check the speed E 2 The most common power timing light is th D C type that simply after installing the air cleaner attaches to the car battery Hook the red lead to the positive bat tery terminal and ii black lead to the negative terminal TIMING To After setting the idle you re rea to make the final and most importa adjustment the ignition timing lot of people neglect timing b cause T they think it is an involved job Tim The third lead of the D C light ing is critical on today s cars and ae the should be set very carefully at every distributor cap The plug wire EE tuneup But timing an engine is is installed in the top of the i u n really very simple if you avoid the E to combate the cir common mistakes of m
47. test But in the mean time here is a very simple way to get good idea of your engine s in ternal condition Pull the coil wire out of the distributor and ground it to the firewall or engine Then crank the en gine over with the starter for about 20 seconds If the engine cranks fairly okay But if there is a lot of variation in the cranking speed a complete com Pression check should be made PLUGS After checking the compression the first ignition parts you ll want to replace are the spark plugs But be fore running out to buy new plugs it s a good idea to remoye a couple of the old plugs and examine them tor see if the fuel mixture is burning properly If you have a four or six cylinder engine removing the plugs should be a snap with a plug g wrench or spark plug socket and ratchet But if you havc a 8 or air conditioning some of the plugs may be tricky to get to Make a survey under the hood to see if you need any kind of special extensions or swivel adapisrs to o get to the e plugs gine down on compression can t be very the compression should be ge heat riser used on mast Evalue cars is located hear the exhaust manifold it ould be regularly doused with solve to keep it operating freely On cars with thermo air cleaners sure the heat tube or NBIpE is Connected at the manifold andat the aig cleaner 45 Bef
48. Also notice that there are two wires that attach to the poiftts Generally the wires fit in a clib and can be simply pulled loose However on some cars the wires are held in place by a small nu amp you may need small ignition wrench to loosen this nut After Ie moving the wires from the points very carefully loosen the condenser then the points by removing the hold down screws Lift the parts off the plate Spray the distributor plate wjt solvent and gently wipe it and the dis tributor cam clean Then take the small tube of lubricant supplied witht the tuneup kit and coat the cam with lube Now you re ready to install the N new condenser and points Place the new condenser as the old part came off and lock it the plate exactly down with the screw Then place the Pede ppinis on ihe plates being very sure Rotor Note where wires connect D ME Points Condenser g the guide hole on the points is posi tioned over the guide post Tighten dam the screw and hook the wires to the points Since the peint adjust ment is made externally with a GM type distributor you can put in the new rotor and lock down the distribu tor cap Now you re ready to fire up the engine and adjust the points _ Locate the adjusting access window _ on the distributor cap see photo and insert the allen wrench that comes with the tuneup kit If th
49. Dirt from doing his thing inside your car s engine Well whether Or not that gasoline really D dirtiest work or at least here you a notice it most As the Place x where the problems caused by a dirt like the Who s Who caused by a dirty or worn carb pany had television commer cial featuring a grimy charac Mr Dirt The erly for maximum perfoemasice and c mileage 8 and for l were emissions s Q db ri NM THE BACKYARD MECHANIC m So it s definitely a good idea to keep x s your carb clean and functioning Prop Thanks to improved a air and gas ub filters on today s cars carbs stay alot lt cleaner and because they keep clean er they frequently last the life of th e without ma jor maintenanc the Yen best iway to Keep e gt continued a THE BACKYARD MECHANIC DS MON a EN Em pora ossibly rebuilt or even re i ltpEANERS C E There Area co ple of ways to re move accumulated g nk from tarb uretor The easiest method is to use q fuel syst m cleaner that is added to the gasoline Just about every auto motive products manufacturer makes this type cleaner that generally sells go by variogys names depending on couple of cans of this type cleaner to the gas
50. any backyard y mechanics First of all the neon bulb timing lights very difficult to use and barely adequate These weak flashing lights 5 can be used only ima dark garage and 777 then must be held right next to the timing marks a 1 of cars newer cars especially getting the light this close to the marks is a hassle and can be very dangerous Ls continued PR T ERO is quite simple y continued THE BACKYARD MECH ANIC since you risk getting the light s leads or your hands caught in the fan So if you don t have a power light your best bet is heading for the hobby shop and using a good light You ll get a more accurate setting with a lot Jess trouble Hooking up a power timing light A C poweted light this type is pretty rare any more simply plugs into a standard household electrical outlet The more common D C powered light has two leads that connect to the battery At tach the red lead to the positive bat tery terminal and the black lead to the negative terminal Both type lights have a third lead that has a special connector that inserts into the num ber one cylinder plug wire pickup on the distributor cap A manual shows the location of the number one cylinder pickup at the distributor cap On in line en gine you can locate the number one plug insert by simply tracing the plug wire from th
51. ator unit and associated mee and fittings As we go further into the a c s THE REFRIGERANT USED IN AIR CONDITIONING SYS TEMS IS HAZARDOUS YOU CANT SEE TASTE OR SMELL IT AND IT CAN T BE READILY DETECTED THIS lt REFRIGERANT BOILS AT 21 DE GREES FARENHEIT AND CAN SEV ERELY INJURE YOU BY FREEZING ALSO JF IT COMES IN CONTACT WITH A HEAT SOURCE IT CAN CHANGE FROM A LIQUID TO AS HAZARDOUS GAS tion remember that what the a c does is remove heat from the passenger compartment not add cold The first step in this chain is the compressor The compressor is nothing more than a pump which is driven by the crankshaft via a V belt It picks up a gaseous re frigerant from the evaporator inside the outside air is passed over the thin tubes Car and compresses it Let s refer to this refrigerant Freon as R 12 The compressor uses an electro magnetic clutch to permit it to be turned off when not needed The R 12 is metered into a c gling coil evaporator normally located inside thesear the firewall at about 30 psi The H2 is in liquid form at this point Its boiling point at 30 psi is just above the freezing poit of water The R 12 there fore tends to Boil absorbing Neat from a the Ag A blower forces either inside or r sider air depending on the setting An ai
52. been arced You ll also need to adjust the btakes several times as they wear in The self adjusters should take care of the adjustments in the normal fa shion when you drive in reverse and apply the brakes However you may need to bring the adjustment up man ually at first so the self adjusters can take over To do this simply use a brake adjusting spoon or screwdriver as you did before Turn the adjusting star wheel parking brake off until Then back off the adjustment until the wheel turns freely Be sure to back off both brakes the same amount ae equalize them p m all the way LG SEEN AT in the May z n our last Backyard Mechanic Wwe covered relining drum brakes How ever wc postponed until this month dis cussion of basic hydraulic svstem checks and maintenance needed car s brakes in top them that wav So we ll run through these jobs here and next month we ll finish off brakes by covering power brake service d PA i These three articles along with the Backyard Mechanic 73 DRIVER should have you covered for any routine brake serv ice your car is likefy to require But as with any mechanical problems if vou have baffling brake trouble we recom mend that vou see vour friendly me chanic or a good specialty shop HYDRAULIC SYSTEM _ Most people knows that thea brake
53. cating degrees after TDC Most cars time before TDC so the marks to the right of the TDC line are what you will be concerned with After locating and cleaning the marks paint over the correct timing mark given in your manual This will FIRING ORDER 223 la i aie ORDER 1 9 4 8 6 3 7 2 them visible 20 tim The engine must be fully idling at the proper speed to set very carefully make a neat line with white chalk or white enamel Check a manual for the type andi location of the tim 1g engine this varies greatly Mark the correct timing lines with white chalk Or paint 10 Start the engine and let it warm the timing While the engine warms check the manual or the information Sticker to see if there are any special procedures for timing Nearly all en gines must be timed with the vacuum advanceline removed at the distribu tor and plugged The best way to plug the line i is by attaching a vacuum gauge or jnserting a golf tee in the s A end of the tine us With the engine warm and i idling at the correct speed and the advance ne plugged aim the light rue d FIRING OROER V 5 4 2 6 3 7 8 marks used on yaur help you see the mark when the en gine is running warmed P _at the timing marks Not aiming the E light properly is one of the
54. ccurs before spark and is then called preigni The source may be an over heated spark plug valve surface or tion glowing cylinder deposit Normally the driver is aware of the problem since the power Joss it caus s is very notice able Engine amans can also resuit from preigRition i teriorated plug boot wrench and try to use a socket during installati t for it A mat gt u Wide electrode gap The plugs elec trodes be worn so badly that igni tion voltage is insufficierf to jump that or air gap You can recondition a plug in this condition but we don t advise it A condition like this greatly increases emissions too and several plugs in the Same engine having this problem may cause catalytic converter overheat be eause of insufficient burning of fuel Bridged gap Deposits may have bridged the electrode gap so that coil voltage is drained away without spark ccurring Exhaust emissions are horrendous withethis kind of plug prob lem but the plug can usually be cleaned Flashover Dirt or moisture or a de can cause volt ge to short over the outside of the insulatgr a Cracked insulator High voltage may Short to ground through a cracked or broken insulator Care taken during installation will eliminate most broken insulators Don t cock the socket or eaffelined
55. ced The valve is factory set and no attempt should be made at ad justing the old valve To replace the valve simply disconnect it from the brake line and carefully install the and forget abeut it But the warning new val making sure the openin g marked is toward the rear not _ the front METERING VALVES Most cars with front dise brakes also have another special hydraulic valve called a metering valve metering valve is installed in brake line to the front brakes Fig 2 and delays fluid press re buildup to the front brakes until rear brake tad l After repairing and bleeding any part of the hydraulic system the warning light may remain on because the pressure dif ferential valve remains in the off center position y 1970 1973 Ford products General _Motdr cars Chrysler products and 71971 73 American Motors cars disc brakes haveya self centering valve After repairs or bleeding is performed center _ tthe valve by applying moderate pressure the brake pedal This will turn out the light 3 B To c ntralize the valve on 1967 69 Fords wire and remove the nylo 21 Switch th ignition on and bleed brakes i Um Tf the front brake system was oV repaired or bled a leak must be created _WARNING LIGHT SWITCH OFF PROCEDURES in the rear brake system and vice versa
56. ck for a worn distributor To do this simply increase engine speed slowly as you watch the dwell read ing If the reading increases more than 3 degrees as you increase idle speed to about 1500 rpm the dis tributor is worn and should be re placed or thoroughly ch cked out by mechanic Also if there is more wt than a slight variation in the dwell at idle or if the points won t hold adjustment y you can be pretty sure ff the distributor is worn sx i E CARBURETION The next step in a final tune is setting the carburetor On post 1971 cars all you really have to worry about is the idle speed All 1971 and newer cars have the idle mixture preset at the factory and a special limiter cap installed over the adjust ing screw This cap prevents the screw from being turned more than one half turn to help keep the engine operating within emission standards It is strictly illegal to remove or tamper with this screw fon Hot idle speed is set at the solen id or on the throttle linkage Be sure to follow all So on a newer car locate the lim specs and special procedures when setting idle gt ee ee iter cap s at the base of the carbu E ad tetor and simply check to see that it iiu CLE M tube J 4 turned out as far as it will go Lo srw cate the idle set screw at the throttle linkage or anti dieseling solenoid and yayov re ready to set the i
57. clean sharp edges m Reset gap remember bend only the side electrode I Some people will condemn a plug if it does riot spark in a plug tester at an the engine s cranking pressure plug tester has little relationship t plug being tested is cold In the engine the electrodes operate at high tem perature and require less to fire than when cold The tester can t duplicate an air fuel mixture Neither does it take into consideration that a plug does not fire at maximum cylinder pressure but actually well ahead of TDC top dead center Lees If you are using a plug tester follow the instructions to the letter and it will give you a good indication of the condi tion of th plug don t throw out a good plug because you didn t follow 27 directions Not Any More Like the engine the modern Spark plug is a carefully engi cializ d technology in ceramics metal JZ lurgy and precision manufacturing i techniques It s also very complicated 2 irr its function and theory right pes Well if you read this article you _ should be a little less confused than before and after all that s the theory behind the Backyard Mechanic Gets Back to the Basics D wer Li e ER N Services Division of Champion Spark b Plug Co for allowing us to extract MERE E from their excellent technical briefs am nr and also for the majority of photos used in this article ar
58. d vance mechanisms are provided for this purpose Engine from the lintake manifold is routed to a diaphragm connected to the breaker plate and _ the breaker plate rotates tb provide an earlier or advanced spark 8 Centrifugal Advance The centrifugal advance mechanism Weights and Springs times the high voltage spike produced by the ignition coil so that il is delivered t the plug at the correct time as determined by engine Speed When an engine is idling the Spark x timed to arrive at the plug just before e piston reaches the apex of its travel C or top dead center At higher engine speeds there is a shorter inter val of time available for the fuel air mixture to ignite and burn Consequently it s necessary to deliver the spark earlier in the combustion cycle to insure com plete ignition anti burning of the fuel The centrifugal advance mechanism consisting of two weights and springs determines the amount of the spark ad vance The weights are thrdwn out due D centrifugal force against Spring ten sion as the distributor shaft rotates with breaker lever assembly increased speed The motion of the so that the breaker cam is rotated in the direction of shaft rotation to an ad vanced position with respect to the distributor drive shaft The higher the ER ginre spegdrthe further the Weig hts draw air from the air tigh
59. d battery voltage during gom General relationship of distributor vacuum advance mechanism and ignition coil White wedge shaped object in center is distributor hold down mechanism When distributor timing must be changed like brated resistance wire connected __ Sistances are bypassed to provide full temperature decreases to room tem ing room for expansion when the coil heats up during normal operation The oil also acts as an insulator to prevent voltage arc over withihNhe coil Iran ignition syste circuit resistance must be pr sent to protect the points from excessive arc sufficient primary perature the oil contracts thus allow ing or burnifig An some systems part of this needed resistance may take the form of a separate resistor or cali graphed for this article DRIVER wishes to thank Mr Joe Hallett during a tune up hold down clamp must be loosened to al ow distributor to be ually rotated ri ght I 2 IPB internal parts breakdown of Pinto distributoG gives general idea of configura tion of most conventional distributors Note use of small nylon pads under breaker plate to ease friction Courtesy Ford Motor Co between the ignition Switch coil primary terminal During cranking most external re battery power to the coil to aid in start
60. d escapes These self bleed ers are available at any auto store for about 2 allow you to bleed the Slowly lines at the reservoir Then tighten all bl ed s entire system by yourself They also make the job easier with a helper If you re using a bleed hose just open the valve and pump the brake pedal but firmly until the cleaning agent is expelled through the valve then close the valve and follow the same procedure on all wheels until the entire m IS p rged of brake fluid If you re not using a bleeder hose have your buddy depress the brake pedal while you open the bleed screw he should tell yoyxwhen the brake _ pedal is just about to the floor so you can close off the bleed screw to keep excess air from bleeding back in Con tinue this procedure until the cleaner exits from the valve then repeat the process on each wheel BLEEDING When the system is flushed you can fill and bleed the system The procedure 15 basically the same as with flushing the system but a bit of care must be exer cised when bleeding out the air First bleed the cleaning agent out of the i a and fill the master cylinder reservoir witb clean hrake fluid Bleed the a from the master cylinder by opening the bleed screw if so equipped or loosen ing the brake line connections and pump the brake pedal until the escaping fluid doesn t make a sputtering sound Close off the master cylinder connectio
61. dle But you don t just adjust the screw until the idle is at the right speed on today s cars Most newer cars require rather exotic methods of setting the idle speed For instance some cars have 10 the idle set while they are A idling in gear with the headlights and all accessories on Always check a manual or the information plate in the engine c mpartment see pic ture for the correct idle speed ane cars newer than 71 the idle mixture does require adjustment the mixture is x adjustment procedures preset at the factory and special limiter caps placed over the adjusting screws On d n Older cars an acceptable mixture setting can be obtained using a tachometri see ud A couple of other points to re member are to be sure the engine is fully warm and off the fast idle cam when adjusting the curb idle Also if the idle is set with the air cleaner off double check it with the cleaner unit in place Finally never try to smooth out the idle by turning the X speed up a higher idle just wastes gas contributes to dieseling On a pr amp 1971 car you will prob power timing light emits a very bright flash and ig ably need to set the idle mixture as more accurate and easier to use than the simple neon well as the idle speed A fairly good bulb light peres idle mixture setting can be made using the tachometer Locate the mixture
62. down your armi is not fun Use a rag and plan _ ahead if you must get the filter out from above or behind obstructions 0 M t After the filter is broken loose with the i will gt 13 Af the oil continues to drain from the oil pan and filter mount get the grease gun Check the end to se that ifs clear of dirt that can be forced into what you ll be greas ing Wipe the gun off with a rag so that it won t be so slippery Try not to have your finger on the trigger as you inspect the end Grease tastes lousy R 14 2 After studying your manual to determine where the grease fittings are wipe the fittings clean put the nozzle of the gun firmly over the fitting nipple and squeeze the trigger If the car has plugs instead of fit tings go ahead and install fittings but be sure to remove them and reinstall the plugs when the job is done 15 This picture shows what happens if the nipple is clogged or if the gun is not held firmly enough against the fitting Grease should seep out of the joint between the two components not from around the gun nozzle Resecure the gun to the fitting and try again Fill fitting until grease just begins to poze out Ball joints and other fittings neoprene or rubber reservoirs should be filled till they are firm and no more much grease can rupture the he 487 E e i 16 Reinstall the oil pan drai
63. e belt by pulling the com pressor away from the fan prying it carefully with a breaker bar if the mount has a square hole by ap lying torque on the mount with a sockef drive Belts should be tightened so that there isno slack and so that they h ve a springy feel Moderate thumb pressure should aem Ni each 10 inches between pulleys Tighten new belts slightly more to allow for beli stretch during break in If the belts continue to slip or are noisy chances are that either the pulley is worn beyond limits or you have the wrong belt Check compressor operation The PT front portion of the clutch should remain stationary when the compressor is disengaged If this portion of the clutch turns with the belt the compressor is Withthe a c selectors switches the clutch should be turning Kh the compressor is not running be sure all a controls are s t on full or max Also consider that some of these fil devils won t go on if the outside tem perature is below 50 degrees F If all switches are set and the weather is E warm the compressor should operate A least i termittel If the elutch still NK to engage pull Iba wire that goes to the for voltage witha voltmeter If voltage is present the clutch is faulty and must ere is no voltage trace ack ward the ignition switch ire
64. e en gine fails to start turn the wrench one way then the other until the en gine fires If the engine still fails to start 0 back and doublecheck work TO adjust the points i th en gine running turn the wrench to the right clockwise until the engine starts to miss or dies Then simply turn the wrench one half turn back to the left This should be the correct point gap setting But the set ting should also be checked with a dwell meter this procedure will be UE covered next month p wl OTHER TYPE DISTRIBUTORS Installing and adjusting points on the other type distributor used on nearly all non GM cars and on most import cars is basically the same ex cept for the point adjustment The ac _companying pictures should clarify t adjusting the steps involved in working on this type distributor With the distributor cap removed the first thing you need to do is remove the rotor by pulling up on it Then the condenser which mount on the distributor plate or on the outside of the distributor hous ing can be removed Next remove the points by loosening the screw and lift ing the unit off Clean the distributor plate and cam then lube the cam as with the GM distributor Install th new condenser and you re reedy for the points This is where the basic procedure differs a Put the points in
65. e first cylinder to the distributor cap On a V eight engine the number one cylinder may be either the first cylinder on the right left bank you ll have to ek your manual After locating the plus wire pull the plug wire out of the cap and install the timing light connector 3 Then reinstall the plug wire into the top of the connector see picture The type and location of the timing marks varies considerably However most manual ls have a diagram Or a picture showing exactly what the marks look like and where ey are located So if you check a anual you shouldn t have any trouble finding the marks But you may need to ro tate the engine by hand or by tapping the starter until the marks become visible Also you ll probably have to clean the grease and grime off the marks with solvent so you can ae m them better timing marks are the vibration damper below the fan There is usually generally 2 x located on the lower front pulley oron ming pointer the engine block e and a series of timing marks on the pulley But on some e giffes there i one mark on the pdfey and ing marks st tionafy Generally there will be mark for TDC top dead center and aj series of marks to the right of TDC indicating de grees before TDC and marks to the left indi
66. e overhaul However there s a very important difference in the quality of the rebuild kits The less expensive kits generally contain only a few new internal parts and new gaskets but worst of all they usually have only sketchy instructions The way to go is with the more expensive kit that contains all the parts needed to com pletely overhaul the carb as well as complete instructions and the ultra essential gauges for M the critical adjustment When you re to be positive y 1 get the Correct one continued ying a kit you have gt Be sure to get the best carb rebuild kits that contain all n cessary parts as well as complete instructions and the gauges needed for making the essential adjustments Most rebuild kits are designed for more than one model carb and usually contain more parts especially gaskets than ar needed to re _ build any one carb Especially for this reason save every removed gasket and part so you can be sure you use the gt proper replacement part continued THE BA BACKYARD ME ECHANIC since one kits vary tor the same carb _ sio depending on the specific model The best way to be sure is to get the num ber from the carburetor identification tag that s usually mounted on top of the carb If there isn t a tag you should be able to find an 1 D number Somewhere on the carb When you pick up the rebuild kit grab plenty of carb
67. ed screw while the brake pedal is depressed listen as the fluid escapes through the bleed valve air is out of the line This may take as many as a dozen openings and closings of the valve so be patient 33 hiversal brake fluid is available fluid that fits the needs of yoy brake system is best When the fluid escapes without making a sputtering sound the Aarau THE BACKYARD MENS But top quality heavy duty 3 gt After bleeding each brake refill the mast r cylinder and replace the cap Check the reservoir frequently while bleeding to be sure the level doesn t get low which would _ allow air to be drawn lin Repeat the bleeding procedure on each wheel in sequence If you are using 1 self bleeder you don t have to worry x about opening and closing the valve each time Just install the hose open the bleed valve and pump the brake pedal inti the cleaning agent is expelled and you think the air is out Th special Valve in the bleeder keeps air from re Apai If re bleeding after relining the brakes the pedal may not Come up as you think it should if the brakes aren t properly adjusted So check this before rebleeding the lines Figure 3 outlines the basic steps for bleeding the brake system A few other hydraulic system prob lems you mightgencounter involve spe at and metering valves Proportio sed in brake systems with
68. em hasn t changed much since 914 Detail improvements have oe been made but components remain basically nthe same _ distributor prim ary circuit d P6 secondary circuit TS P nS f points to open and close When the rapidly the primary winding of the duced in the coil s secondary winding about the phenomenon of I tage flows spark plug The voltage arcs from the center electrode of the plug to the ground or angle electrode igniting 5 The secondary current flows from the secondary winding across the dis bur rotor gap and spark plug gap ignition coil soq baek to the winding through ground the battery and the ignition switch The contact points then firing spark plug will then be the one connected to the distributor cap insert that aligned with the rotor when the gontact points separate With the en gine running current flows through the coil primary calibrated resistance wire the other lead connected between the coil and solenold terminal is a by feature nore about this under COILS When the contacts separate high voltage is induced in the coil s primary winding This voltage about 250 volts causes an arc to form across the con z sul va I a EE
69. ent stability of the control module dwell adjustments will never be needed with the Duva Spark system Signal generating systems generally follow the pattern of a gear shaped iron s y I RESISTOR _ josTalauTog rotor or armature driven by the dis tributor shaft which rotates past the stationary pole piece of a pickup coil The number of teeth on the armature correspond to the number of cylinders in the engine A weak magnetic field is provided by a permanent magnet which is part of the pickup assembly AS each tooth of the armature moves away from the permanent net an electrical signal of opposite olarity is generated in the pickup coil stator As the armature tooth nears the magnet and moves away as the distributor shaft rotates the signals generated go from positive to negative however when the armature tooth and the st tor tip are aligned the signal is zero be tween positive and negative This zero signal tells the control module to turn off producing the same effect in the coil primary circuit as the and closing of con tacts in a conventional ignition system it breaks the primary circuit The sudd n stoppage of current in the ignition coil primary windings causes the magnetic field to col Japse and induces high voltage in the coil second ases ther time span be
70. er core at maximum cooling only check the vacuum line to the valve If the line is not cracked or kinked have the valve checked If the a c works OK for 20 to 40 utes and then begins to go away the evaporator core is probably freezing up The suction throttling valve de icing switch causes this and will have to be inspected or repaired by a qualified a c person HOBBY Don t forget your installatioM hobby shop when you have a c problems Most shops have the manuals you ll need and many have skilled tech nicians that can help guide you through the maze of wire tubing Also as with other Backyard Mech e anic articles we advise getting and using the correct shop manuals and safety equipment A C servicing can require safety goggles insulated gloves pres Sure gauge sets and special pressure vess ls and connections i a _ Don t be afraid of doing your own E troubleshooting butrememberthatmajor a c repairs are best accomplished with epu litte qualified help e 3 The spark of tite for your car gnition System have come a ignition systems the next issue we ll move on to the latest generation of high energy systems 7 veloped by Robert Bosch and Frederick Simms In late 1913 the fi rst real in i
71. erence to the piston position _ The spark from the spark plug then ig nites the compressed fuel air mixture with the resulting explosion forcing the piston back down the cylinder and pro ducing power a The ignition system involves two in dividual circuits One of these is the primary circuit composed of igni tion switch primary winding of the tion coil distributor contact points and condenser The other is the secondary or high voltage circuit including the secondary winding of the ignition coil the high tension lead distributor cap Totor and spark plugs When the ignition switch is closed current flows through the primary cs cuit in this manner battery fo through primary winding of th tion coil to closed distributor c points to ground and back to the als A multi lobe an on the rotating j r With the possibile exception of some Ford where they are hard to get to This Chrysl 340 engine is a good example GM pro D distributor s shalt causes the contact points open the current decreases ignition coil and high voltage is n induction later 4 This induced high vgl through the distributor cap to the rotor through the spark plug lead and to the he air fuel mixture ye r Hm This Of the Kettering ignition sys Setem ey the syst
72. f the engine If you re changing to a different heat range plug be especially careful If have trouble determining what plug to switch to take one of the old plugs to a parts house and have them T s t you yp with the right plug SIEUT f While picking up your plugs you qan grab an ignition kit Ie set for your tuneup The best gt EC Removed spark plugs should be read for correct burn The distributor on most GM products is removed by turn New plugs should be gapped to specifications before in ing the special lock screws until they release Non GM cars have stallation ac wn iT p held in place by external clips that are popped off with a V ete uA i screwdriver a GM distributor Rotor Condenser Points contain a rotor condenser and E points Just be sure and get the cor rect kit for your car and engine As with the plugs the kits may differ for the same engine depending on the year or horsepower rating After figuring out how to remove all the plugs if this is a problem on your engine all you have to worry about is gapping the new plugs Most plugs are pregapped at the factory but double check each plug with a gapping tool to be sure it s at the gap specified in your manual Replace the wire immediately on each new plug to prevent mix up In stall the plugs one at a time and snug
73. g a brake job But when you bleed the hydraulic system it s a good idea first flush the system with special poe system cleaner or denatured alcohol CLEANING To flush the hydraulic system you first need to bleed the fluid out of the master cylinder reservoir Open the bleed screw s if the cylinder is so equip ped or loosen the brake unit Have a buddy pump the brake pedal slowly but firmly while you catch the escaping fluid in a suitable contain er Be sure not to let the fluid leak on the car it can ruin the finish When vou ve got most of the fluid out of the reservoir tighten the bleed screw or brake line connections and you re ready to begin flushing Fillahe master cylinder reservoir with cleaner or alcohol and go to the wheel closest to the master cylinder usually the left front and open the bleed screw on the backing plate behind tke wheel Here again you want to be su to catch the escaping fluid A length pf r bher hose that fits over the bleed valve to One of the most common causes of poor braking is contaminated brake fluid As previously mentioned the hv draulic system operates on the principle that fluids are not compressible So even small amoiint of air Cwhich is highly carry the fluid to a container is a good idea Also you can use a special bl d ing hose that bas a valve in the end which doesn t allow air to bleed back in after the flui
74. g for whether Buying used e a you re in the market for a late model lt whole lot easier and lot J isky car or just looking for a drive around thanks to the development of scientific towri second Car NE e automotive test centers And we feel pe ee that anybody who buys a used car LATEMODEL oss V Swithout having completely checked en you re shopping for a j out by a reputable independent test model car the first thing you should do center is only slightly short of crazy is dacide what type style or model car Because along With indicating if the you really need and how Tuch you can car is safe and sound by thoroughly afford to spend The looking around checking the basics like the front end 2 3 for a good deal approach you might suspensi n system brakes diagnos s x use when shopping for a clunker isn t tic testing tells th exact tune and in always the best bet for buying a late ternal condition of th engine through model car Remember that prices will electronic analys pe _ most likely continue rising so either A A Although diagnostic test will run by choice Or necessity you may be E 8 jut a or 20 there s no way you continued Eyeball a
75. gnition systems was developed by harles Kettering at his Dayton En gineering Lab later known as Delo for use on the 1913 Cadillac This ignition system still kno as the Kettering system is the coil igni _ tion system It was used from about 1914 until the mid 70s and was the most accu compact and efficient ignition long from the red hot Dati tube used to ignite fuel in gt the arly 1900s to Today s breakerless i ignition Systems S In this issue we ll cover late model coil Quick History Until 1914 ignition sources were either the hot tube or E high or low tenaign magneto de today products distributors are always placed 4 ucts and Chrysler slant sixes have the same Leve until t the 2 advent of the r new ew ger eration systems c ignition Basics The parts composing a the Kettering or coil ignition system ate _ the electrical energy source battery i ignition coil condenser distributor igni tion switch low and high tension wiring d and the spark plugs The ignition system is tasked with producing high voltage surges and then directing these surges to the correct Spark plug at the correct time The surges or sparks must be timed to ar rive atthe spark plug at an instant near the end of the piston compression stroke in ref
76. gnment indicate that he was a bit sloppy with other basic maintenance such as oil changes and lubes Don t forget to trunk and make sure the SpRre tire holds air and the jack works perly replacing these two essentials after the sale can make a good deal not so good S EERING AND S SPENSION Although it s a bit difficult to tell much about the car s suspension there tion the shocks should be okay If ti car bounces a few times the shocks of each front wheel and Pu firmly A probably worn Also grab the top y holding down firmly on the pedal for tiny s seconds system js okay little play is acteptable but if there s a lot of give there may be suspension or wheel bearing problems If possible check underneath the car to see if the exhaust system is in good condition _ not rusted and if hes car had a recent lube UNDER HOOD The next step is opening the hood and having a look around If the engine hasn t been cleaned check for oil leaks A lot of oil and gunk around the oil filler tube means internal engine prob lems Pull the dipstick and look care fully for water droplets that indicate a blown head gasket and a very costly repair bill If the oil is very dirty the owner probably wasn t careful about regular maintenance RADIATOR E Check th J radiator for any signs of jay seas am overhegi fiis if it
77. guards behind each x bumper for rust and crash damage if the bumper brackets are new or welded YOu can assume was smacked Md hard Dod i Check the wheeb rims dor ARA dew dents are not uncommon duri ng x Ordinary driving but lot of dents or especially large ones are a good sign the cr was driven pretty hard Natur ally you ll want to check the tires for s condition and tredd depth as well as tread wear patterns Uneven tread wear is important for a couple of reasons First its a sure indication that you Te jen the to system through casual observation you can check the steering play and shock absorbers Watch the front wheels while you slowly turn the steering wheel en gine on with power steering should not be more than two inches of play before the wheels turn If there s excessive play youre in for a fairly AUR costly adhe or possibly Fiore seri ES ous work You can get a rough idea of the condition of the shocks by the bounce test Push down on each end of thes and release it If the car Teturns to its normal position in one smooth heck brake system b f the pedal stays firm the brake E g ing to have to Sink some money into front end work and or wheel balancing Also the fact that the owner drove the car with the front end out of ali
78. h Pretty impressive statistics huh co Yes and they illustrate that ignition 0 00 tee ae M Systems in gerleral can provide heo I EE 5 most startling difference in engine per m Nn he ere A formance when not operating correctly A a i spark plug i a i vu ated mechahic that is use 27 Re er 25 CUTE the linder haad O arnal tF zr the incredible oun pressures involved in combustion and 8 fe it must do all this millions of times highly corrosive atmosphere iu SE AUS Heat Range If you ve been around 2 Type of where ve ES NS aD dm Tu very Y simple really The center is insulated from r fastened to ae Erat grouhdi to the cylinder he EE jflowst from the eae do 2 combustion begins Spark occurs Sul Spark occurs combustion begin ni remaining fuel flame fronts collide ROUNDED EBGE WIDE GAP Notice how the used plug left and the plug that has only been aie similar By just r gapping aen ae acc 3 plishing anything right A plug that has been abrasive blasted regapped offers ponar than Just agr h c y use the insulator deposits have been removed NM 2 FD MU x i i SHARP
79. h to oil performance and they also want to remind you there is the possibility of a voided warranty if sucha product is use when certain types of engine failure occur Get Going We hope we ve convinced you that a job Ho am oil and Dn c rease Oil and needs so let s tag along with Belinda Jean Proietti of the DA section of AFISC as she trips on over to the Norton AFB Auto Hobby Shop Lindy a San Bern rdino native tists poetry dancing and baseball as her hobbies and tells ussthat she works on her own most of the time she watoh s her odometer carefully so she ll know when a lube job ands an oil and filter change are needed This petite attractive young woman prove you don t need to be male or professional mechanic interest in your car andet mainten wetised our photdg rapher s car for the pictures ance Although w we might add that Lindy s car is a VW with over 100 000 miles on it She thinks that proves the value of preventive maintenance I a Mes gue E ME continued filter change are just what your car MASS linda Jean Lindy Proietti E in the Norton AFB Auto Hobby Shop grease oe oil and fiter anager gives Her the tools necessary for ob not a bad deal Jor 79 cents she ranna can
80. hRe pedal is depressed by pushing out a piston inside the cylinders exerting pressure that is transferred hrQuigh the system MASTER CYLINDER CHECK TOM sean fails since braking action will b greatly reduced and on new r gars the pressure warning light on the dash board should illuminate But it s a good ideato check the upit for leaks when you check the fluid level in the r seryoir The master cylinder reservoir should id loss will indicate a leak in the wem that you be checked regularly since can track down ang repair efore it be Comes seridus To check the fluid level clean all as off the unit and mes 731 ms Mc 2 a After shed the wheel area for and signs of abrasion points where the lines turn or bend around obstruc tions om the underside of the frame If you don t spot any leaks along the brake lines you can move on to the master cylinder is the heaft of a a PUE the master First of all continued THE BACKYARD MECHAN IC he wire bracket ie what ar locking device is on the top and E Ne the lid qf th level AS dnd slightly the brake line connections and refill the reservoir with fluid and check the level again in g couple of days some fluid loss is ormalz Although its 7 nat likelye the fwd level could be very low without your beirfg
81. he car you re ready for a test drive Listen carefully when yeu crank the engine The engine should start quickly and easily After the engine warms a bit rev it a few times and check the color of the exhaust smoke If the exhaust smoke is black you re in need of at least a carb adjustment But if the exhaust smoke is blue there s a definite engine problem Run the engine at various speeds and listen for misses hesitations or unusual noises Any irregular engine operation is an indication that at least a tuneup is needed and it s a good rea i termine the should son to have the car diagnosed or at least a compression check made to de internal condition of the engine po b After you geta feel for the car head out for a deserted stretch of road where you can safely make some quick stops to check the brakes On tlie way you can make a few acceleration tests to further check engine operation From a standing start accelerate briskly and smoothly to about 50 mph The car accelerate without missing or making any unusual noises check the rearview mirror for blue smoke while you re accelerating Also be listening for any unusual mechanical noises like traansmission cl nks Blue exhaust smoke or strange noises are good rea sons to look for another car When you get to a nice stretch af deserted road where vou can safely test the brakes make some progressively harder stops Make sure t
82. he car stops evenly and quickly without pulling screeching or making any unusual 2 p to get the car in shape And noises When you get the feel of the brakes trv locking them on for just an instant If the brakes won t lock there s something wrong with them Finallv drive the car over various road surfaces to get a feel for ride com fort and noise levels If the car drifts on the road or won t track straight down the road when you release your grasp from the wheel briefly there s a definite alignment problem If the wheels seem to bounce or hop you know they need to be balanced EN So if the car rides ahd handles to your liking and evervthing else checked out you may have just bought a new used car congratul tions But if things didn t check out just right be prepared to look for another car or make sure the deal you re getting is saving you enough so you can afford if you just picked up a second car clunker check out this month s article on keep ing up an oldie on page 16 aie BARGAIN truth is that your car operates at best efficiency when it is tuned properly to r ecently many people have Bot very tune conscious not musically but mechanically Fuel shortages and bigh gas prices make maximizing gas mileage the in But many drivers still think there are super trick ways of tuning a car to double the
83. he idle ts reasonably close the gap One lead of the dwellmeter hooks to the positive coi covered with an insulator boot w the switch to either cylinder whichever is see picture If vou are tesung a four cylinder engine set the selector on eight cvlinder and menti Hy double the reading After getting thes meter hooked up and properly set chetk a mantal for the dwell spec on your engine The dwell specification may be given as a single value or in the form of an acceptable ranges For six or eight appropriate instance the acceptable dwell might be givens 36 the best bet is 10 sh ot dor the middle to 40 n this case of the range To check the dwell simply start engine and take the reading to the proper speed to insure a correct dwell reading not to specs the points need to be readjusted Too high a dwell the points are staying closed too long the low dwell reading means points are not staying closed long enough s to be 10 remember this 1S that lift the boot slightly and wrap one end of a straightened paper cilp around the terminal Then clamp onto the paper clip hassle Ii the dwell angle is over the engine just long enough to T gap needs to be widened A lo narrowed The rminal If the terminal is Before testing the neh set the meter either tach or dwel and to six or eight
84. he oil drain holes ir the rear f the cylinder heads are clogged due to sludge excess oil may pulled into the cylinders via the intake valve stems This will probably noticed in the two rear cylinders first since the engine slants in that direction High oil consumption and smoky ex haust when starting may RCCOmpany this condition Cleaning Used Plugs To use or not away at the rate of 005 to 008 inch during anormal service life of 10 000 miles Plugs should be replaced if they measure out of these limits Renewal suitable for further service and the following procedures should fol to permit cleaning and filing ator and then use clean air while foul air pressure equal ta or greater than WRONG Air pressure as read engine cranking pressure Why The neered product combining highly spe that is the question relative DRIVER wishes to n Technical to used plugs Electrode gaps wear r should be performed only on those plugs lowed A Remove any oil deposits with a safety solvent and dry plugs thoroughly W Open the electrode gap wide enough Use an abrasive cleaner sand blaster to remove combustion deposits on both the electrodes and the insul wearing your safety goggles to blow away all abrasive dust Clean and dry the threads and connector terminal m File the electrode surfaces to restore
85. he rod should not be removed Also when removing the unit be very careful when disconnecting the brake lines When you get the brake lines re moved all you have to do is pull the stoplight switch and unbolt the unit from the firewall or power unit Before disassembling the unit clean it very thoroughly with alcohol When you remove parts clean each one in alcohol and lay it on a clean cloth in the order in which it was removed Make sure the unit is clean on the inside and check the piston bore very carefully The hore k st be smooth and ne unmarred If the bore is slightly dam EI A E aged you can probably clean it witb T crocus cloth b t if it is badly scoured it must be honed smooth or the entire unit replaced Finally when reassem bling the unit be extra clean Carefully follow the instructions step by step and lubricate all installed parts with clean brake fluid Figure 2 has blow ups of t single and dual master cylinder which vill give you an idea of the parts in volved The master cylinder generally should be bled after being rebuilt this will be covered later T UID L c mpressible in the system can seri ously affect braking The system should be bled whenever the brake pedal gets spongy indicating contaminated fluid or when the system is opened at the wheel cylinders or master cylinder duf in
86. ifold to the air cleaner intake previously mentioned Back yard Mechanics cover thermo air cleaner maintenance but your pri coficern shouldbe checking to see that the heat tube is eae be sprayed down the carb throat ac cording to the instructions on the can The outside 9f the carb espe cially the choke plate and linkages should also be sprayed clean with carb or choke solvent Be sure the um choke operates freely continued F nne evenly continued ee vp BACKYARD MECHAN me After out the items as well as basics like the drive belts and the master cylinder reser you re ready to get into the actual tuneup The only tools you need in addition to ordinary hand tools are a pl g gapping tool and FE voir feeler gauges unless you have a GM product in which case you don t sven need feeler gauges Naturally you ll need spark plugs anta guneup Ki these are discussed later tells you the internal condition of the engine primarily what kind of shape the valves and piston rings are in This check is important since an en effectively tuned and some Sines can be damaged when run with burned valves ES In a future Backyard Mechanic we will feature an entire article on doing a thorough compression and cylinder balance
87. ight to the master cylinder ELS D OPERATION mur o 2 E Ns Most power brake units consist The poweri brake assist unit is jbcatari be tween the master cylinder andthe fire and vacuum connection from the x M spect connecter where ur engine intake manifold When your vacuum gauge can be attached MUT foot is off the brake and the vacuum LEA UPS vacuum system intake port IS closed I uw uM A special atmospheric port remains E sid of the vacuum piston to the other This maintains equal pressure on the piston and keeps itin the off position G When you hit the brake the at em ON ee a mospheric port closes and the vacu DNE IUE K PG deus odis um port opens Vacuum from the en ee epee oe gihe then sucks the unit piston fors 2 ut com vt on Tad sc ed ward against the master cylinder JM EM CE E NAT ee ating rod and actuates the brakes I NEIL X the power unit fails or the engine dies m _ Pulling the vacuum Madat the power ae sist and checking for suction is the first assisted braking or a few seconds step in tracking down E Ppwer brake But after that you re going to Have to problem use plenty of leg power 0 m PET MANT The important thing to remember MR power brakes is don t freak out gt KD UN always stop Power brake
88. ill below Inere a vacaum operated water Valve normal Suspect the blower or tempera ture control system lf ithe blower operates on all speeds sats ite when the blower control switch IS oved it s operational If it loperates on only ohe or two posi and should leak checked and re tion or speeds suspect a faulty blower Charged If you see severe bubbling or resistor This gem is located usually in the engine Gompartment on the evapora tor housing Remove it and chec burning or shorting coils If the bl wer doesn t function at all run a jumper wirefrom the positive battery terminal or the fuse block to the blower motor terminar If it still doesn t even though the blow r is goo i temperature control system may be the check the ground strap If the system output is inadequate glitch Have a b ddy move the tem perature control leve back and forth white you look urid r thesdash for a mov ing control cable when Under hood or lt dash remove rings watches bracelets The cable operates either water valve an air mixing door If there is n ap parent cable movement but shifting the temp control knob has an effect on com pressor operation have the thermo static switch checked by your E alc serviceperson ie 251 for the is used to stop coolant flow through the heat
89. in a Kettering sys In a future article we ll give you the em Since the points carry less current Straight skinny on spark plugs and how they encounter fewer problems than the they can really make or break the per onventional systems points do _ formance of any ignition system p CDIs employ a solid state device to TAE rigger the high voltage and this trigger PICO RE S or electronic switch 9 called a siicone NOTE There Ish ISN Lengugnr apate ontrolled rectifier or SCR in DRIVER to go into the whole opera SCR operation as concerns CDls is tional theory of solid state devices and again very complex 4f you wish to know associated circuits If this article whets iore about the operation of CDis con your appetite or if some circuits are ult one of the reference works we ve COnfusing may we suggest the follow isiad al ipa end ol the article ing reference works most should _ be available at your post library Which One Is For You If you avea practical Electricity by R G Middle ew car of course the choiceris already on Audel ade for you lt is nearly impossible to 73 ansistor Technology by Bridgers tempt covert he new EI or Duar Seat and Shive Bel Lab Series Electronics by Robert Irving A Knopf DI or transistor ignition In actuality you would be dealing yourself a losing Semiconductor Fundamentals by and Marshal Wiley
90. ing dwellmeter tells ex ex N actly y What the point gap is and ee rate and very difficult to use The ee for a more exact adjustment oo IDY Some people think tHat if the points are set t carefully with a feeler e 1 boot you wert n gt ghtened gauge there s no reason to check the dwell But this isn t true as evidenced by the very existence of dwell meter Generally if the points are set to specs with a ga ge they ll be pretty meter should be part of very y tuneup To use the dwellmeter all you L on the dwell but not have to do is attach one of the meter s leads at the coil and ground the other lead Trace the wire that lt 5 runs from the distributor to the coil e Clip positive dwell lead red clamp to this terminal If the termi nal is covered with a special insulator connection In arable to get d direct this case pull the boot slightly and wrap one end ofa ten aper clip around the inal push the boot back dowh Then cl mp onto the free send _ of th clip td make your connection pi cture Make sure the lead Is vane any other metal then Simply glo ithe other lead Next p the meter to dwell if dti is E U a combination tach dwell a x ES the make sure t
91. ing You should always use a torque wrench when installing plugs and in stall to the values listed in Chart 1 These figures maximum readings and a based on clean and dry threads on piis and in Cylinder heads The final tightening of plugs in cast iron heads should be done with th en gine at normal operating temperature installation in aluminum heads requires does it Mis Fire ol No Fire Assuming that an erigine has adequate compression that fuel and air are mixed in the proper proportions and that ignition timing and dwell are correct ignition of the charge may occur any of several ways Actual misfire may be due to lack of proper mixture in the cylinder When the Spark js lacking however it may be due to one of the following reasons Torque plugs in aluminum heads with the engine cold at roorn temp Plug r Care because of the ease with which the threads may be stripped Easy Tracking ignition This occurs when the spark jumps from one deposit island to another and ignites the fuel charge at some point along the insul ator nose The charge does not actually misfire but the effect is to retard ignition timing Power and economy are affected without the driver being aware of the problem Surface ignition May occur ae 2 some surface in the combustion cham ber becomes hot enough to ignite the fuel charge Usually this o
92. into the power unit but not through the end that attaches to the vacuum line Install a new valve if the old one is faulty being sure to get the unit placed securely in its grommet If the valve is in good condition but the power unit doesn t operate you better head for the local brake shop or pick up a factory rebuilt power assist unit and bolt it on As previously mentioned power assists are hairy to rebuild and should always be replaced with a new or factory rebuilt unit good service manual has the specs on this job for your car REGULAR MAINTENANCE Most power boost units have a filter to clean the air drawn into them On a few boosters the unit is external and should be periodically removed and cleaned with alcohol check your manual for the specs However most units have an in ternal filter that should be serviced when the booster is removed from the car One final check you can make on the power assist unit is making sure there is no brake fluid being sucked through the vacuum line into the in Y jj T 5 ing the power unit the master cylinder very carefully for leaks Fluid leaking into the vacuum unit from the master cylinder may be the cause of the excess fluid In this case the master cylinder should be repaired or rebuilt t ke manifold the manifold and run a pencil around the inside
93. ire is mast likely to occur between consecutive firing cylinders which are located close to gether in the ngine block Cross fire can cause engine rough ness and damaging preignition or de tonation So even though it may no look pleasing run your plug leads in a Detonation can cause actual plug damage To stop detonation try retarding the igni tion Slightly using higher octane gasoline and a richer mixture manner so that they won t run parallel for any distance and separate plug wires for adjacent cylinders by placing opposite ends of the plug wire holder or loom N Troubleshooting With Plugs Champ ion Spark Plug Company notes that close examination of spark plugs can di give you clues about the fitness of your engine Just as important as the ex amination though is keeping the plugs in order according to their cylinder position The location in the engine may help to locate a problem that otherwise might go undetected The some of the problems in the engine which may be located by keeping iagrams in Chart 2 illustrate a to use the backyard mechanic continued plugs in the correct order Telltale plugs colored black if fouled and red to indicate an averheat Fig 1 two adjacent fouled plugs in a six cylinder engine There s a good chance that this is due to a blown head gasket between the two cylinders Fig 2 is d
94. isting of a roll of two layers of thin metal foil separated by cause the cam to rotate thus advancing the spark earlier into the combustion cycle Vacuum Advance Since centrifugal ad vance isn t really effective at low engine speeds we must have another means of advancing the spark under conditions of low engine speeds or partial throttle openings This low speed advance is accomplished by the vacuum advance system The vacuum advance mechanism has a spring loaded diaphragm connected by linkage to the distributor breaker plate The spring loaded side of the diaphragm is air tight is usually connected to an opening in the carburetor This open ing is on the atmospheric side of the thir Sheet of insulation This assembly is sealed in a small metal can with a flat washer providing a tight seal The high voltage induced in the coil primary winding causes the condenser plates to charge when the contacts first separate the condenser then like a short circuit and current flows into the condenser to minimi ize arcing at the points Coil The ignition system TET be of much help if it didn t have high voltage to deliver to the plugs In order to develop this nigh voltage we rely on the ignition coil An ignition coil is essentially a pulse transformer that steps up the low voltage fr m the battery or alternator to
95. l the drums the best bet is to check to be sure the local shop has parts for your car before you begin You ll also need some transportation to get you to the shop to pick up any needed parts since you can t very well drive 4 can cause the your car without the rear drums To finish your preparation locate a machine shop that offers while you wait service in case you need to have the brake drums machined Manv base auto hobby shops have the spe cial lathes and equipment needed for doing brak machine work So if you re not working at the hobby shop you may be able to save some bread having machine work done there When you ve checked out the local parts house and machine _shop you re set to begin If you ve got your tools and a clean surface to lay out parts on all you need are some clean rags ahd denatured alcohol Yu should also have some paper and pencil to make any sketches of the brake as sembly needed to supplement the dia grams in your service manual Some smart camera enthusiasts find a black white Polaroid is the easiest way When you ve got everything organ ized chock the front wheels to keep the car from rolling and carefully raise the car s rear end just enough to get the wheels off the ground Place safety stands securely under the car s frame Remove both rear wheels and release the emergency brake Finally place q block of
96. l the 43 ohm collector the transistor col lector and emitter the common 33 ohm 0 the battery Since this circuit supplies the power to the ignition coil we refer to it as the power or cbil circuit During the dwell when the contact points are closed current flows in both circuits When the points begin to open the collapsing magnetic field produced in the toroid sends a reverse pulse through the control circuit stopping all electron flow in the control circuit Be cause the control circuit triggers the power circuit current stops in the power This causes magnetic field pro duced by the coil primary windings O collapse and sends very high voltage generated by inductance in the coil oy from the coil to the spark induced in the primary windings of the power circuit Normally this would be sufficient to cause transistor destruction inasmuch as the induced voltage instantly rises above the load level of the transistor until it teaches the breakdown level of the zener diode So this is the reason we incorporate the condenser in the power circuit it absorbs the high voltage current and keeps it within load _ limits until the zener protection level is reached Discharge of the condenser voltage from zener level to system volt takes place by revers flow through the power
97. ld check the hydraulic system regu larly to be sure the fluid l vel is up and the system is not leaking A quick and easy check 15 to simply depress the brak pedal and hold it down with plenty of force If the pedal stays firm the system is okay But if the pedal gradually sinks to the floor there s a hydraulic leak somewhere If your car has power brakes or vacuum assist disc brakes which mos newer cars have this check should be made both with the ngine engine off pump the brake pedal six or eight times to release the vacuum before holding the pedal down Any time the pedal fails to hold firm you should immediately find and Te pair the eak before it resulls in brake continued running and with the ignitian off When performing the test with the us 145 AIR VENT FILLER CAP MASTER CYLINDER ASSEMBLY FLUID RESERVOIR g PISTON SPRING was E pum WEN PISTON BRAKE LINE BACKING WHEEL CYLINDER PISTONS LINK 7 d 100 55 FORCE Fig 1 BASIC HYDRAULICS Principle of hydraulics illustrated 108 Ibs of force in the cylinder is applied such as your foot on the brake This pressure is exerted equally in all directions so there is 50 pounds of force against a cylinder with a 0 5 square inch bore and 100 pounds against a cylinder with a one square inch bore 1 My y E SNAP RING
98. lly if you do th job yourself Of course you want to be sure he carb is really what s giving you trouble If a sick carb is the problem there 5 no reason why the average back yard mechanic can t pull off an older model one barrel carb anid completely rebuild it Also if you have a bit of experience with carbs and or you work very carefully and follow in structions you should be able to han dle a two barrel carb As we mentioned previously the post 1970 carbs are specially cali brated and equipped for reducing emissions and should not be tamper ed with However if you re having carb problems it s not a bad idea to remove the carb and give it a thorough cleaning and check for obvious prob lems Uke a puna float If the REBUILD carb still gives y u trouble after it is cleaned and properly reinstalled your best bet is heading for a good me chanic or replacing the carb Okay let S say you have an older carb that s in need of a rebuild The 2 gs very first thing you should do is get amanual that outlines the job for your carb step by step If you re not sure of yourself after checking out the procedure don t do it Save your self time and trouble by getting factory rebuilt If you re confident you handle the job you can save a bundle by picking up a carb rebuild kit and doing th
99. long major y panet for ES or body Be larities that mean the has been pressed out after a smack Check the rocker panels and behind the bumpers for r st f oa He E The bounce test will give you a general idea of the condition of the shocks If the bounces a couple of times before r turn ing to its original position when depressed the shocks are worn 4 K 7 u recourse if the car has problemi ol course if you re saving a bundle p th going price of the car you c n afford to amp pend a bit on minor mainfenande after the sale i So what this boils that you weigh the advantages and disadvan tages Qf each buying situat jon as they apply to you But if at all possible e recommend not buying a car that have not had thoroughly checked out by an independent diagnostic center And df you ve never dealt with a diagnostic _cenf r most American Automobile Association AAA offices keep aj list of reputable diagnostic shops in their are But let s say for some reason you can t have the checked out of you want to be sure you don t have a total lemon before spending the money on having the car tested Well there are some basic checks and should make before purchasing any used car Before we get into the of checking out a used car however we want to poin
100. me type unit and now most new utilize a combination type valve These combination Valves nor mally located at or near the master cylinder a ch ck manual for the location and Specifics on your car The entire unit must be replaced if any of the functions fail Once again E there isn t any trick to replacing ides quite today most t People who pay the exta oney pay Howe power br k s more than a standard Ay draulic brake System with a vacuum assist unit between the brake pedal 25 and the master lin ler to help you power brakes dune pus the in kei manifold pulls the assist unit master cylinder actuate red oper ating the makes The fact hat Ou brakes where the brake pedal i i linked basically of a piston control valves unit is in the released position E 4 open to allow air to pass from they should be any time the brake ifthe power fails or the car dies You o i8 lot of muscle on the brake pedal 2 what basic checks make before Tustin down to the local brake shop j When are fiom h m ster a der by the vacuum unit is why you don t have as good feel with power brakes as you do with manual r
101. ming set you can test the mechanical advance by gradually in creasing engine speed while aiming the timing light at the marks If the advance is working the timing mark will jump ahead older cars you can also check the vacuum advance N by reinstalling the vacuum line at the distributor The timing mark should jump ahead slightly On most cars since 1971 there is little or no vacuum advamce at low speeds so gt you can t check the vacuum advance this manner Now you re sdb done But 0 back and quickly double check every thing again just to be sure you ve got the engine super tuned for max per formance and gas mileage You might also consider going to a dyno tune shop to have your car s engine scoped and dynoed For a modest price around 10 you can be doubly sure everything is working right and that your engine is super tuned f t T M or A 1 NE i i i 4 s easy to VR stopping a rakes are the one part of a car that nearly every driver is concerned about And its no wonder losing your brakes would be traumatic at best Although brake failures are quite rare with to day s dual master cylinder heavy duty brake systems your car s brakes do requir some basic care and main tenance to keep You gepping surely and safely E The most ance is checking the brake linings This is the subject we ll
102. n plug Then prior to iastalling the new oil filter wipe down the filter mount on the engine block and apply a thin film of oil or grease to the seal on the filter canister 3 17 New filter goes in the way the old one came out Instructidns say hand tighten but to be sure it doesn t leak you need hands like Goliath better to use the filter wrench and tighten snugly but don t over board and wrinkle fhe filter canister S diu Check to be sure you re installing the proper grade and welon of gil far your car s needs 4 z STE PET NO install the amount of oil called for in your owner s manual T oil filler cap and PEY or mog connections va Don t forget to reinst ll if PATET 20 Check oil level fire up the car and check for leaks from filter and drain plug turn car off and recheck oil level Clean your work area r turn the tools make a note of the odometer reading and pat yourself on the back for a job well done and quite a few bucks saved E 5 x 0 2 GOVERNMENT PRINTING OFFICE T 1984 O 443 270 THE TRAFFIC SAFETY MAGAZINE FOR THE MiLITARY DRIVER nS
103. ns and refill the reservoir Check a manual for the correct Bleed ing procedures and sequence for your car Usually brakes should be bled be ginning with the wheel farthest from E wheel closest but this varies bleed po s E Brakes can be easily bled by one person using a special bleed ing hose available at any auto supply store Bleeding done manually by opening and closing the as someone pushes on the brake pedal Special bleeding hoses have check valves that prevent air fron bleeding back into the system and eliminate the need for opening and closing the bleed screw The hose is installed on the bleed valve 55 the brake pedal pumped until the air is released from the syst m Brake fluid should be bled into a container end thiown icc out never use old brake fluid for any purpose working to the I Begin bleeding by opening the bleed screw on the appropriate wheel a quarter of a turn Have your buddy depress the brake pedal slowly as before letting you know when the pedal is near the floor s you can close off the screw Continue holding pressure on the pedal and opening and closing the bleed screw ntil all the cleaning agent is removed the master cylinder 9 and a steady stream of fluid escapes Now you re ready to bleed the air Following the same procedure of opening and closing the ble
104. nt factor in c nducting the heat from the plug to the cylinder heads Unless plugs properly tightened and gasket tension is Correct this heat flow ay be iriter r pted Spark plugs used on some cars like FoMoCo products do not use gaskets but rather the plug seat is _tapered so that when installed the taper becomes the cold plug may be ruined by exces sive heat if driven hard when it s not tight and if hot plugs driven hard wher not properly tightened we guar antee they ll go out t finch usually somewhere between Blythe Cali fornia and Quartzite Arizona Aftef you Ve properly gapped the plugs to be installed Use a gapping tool or one of the gauges available continued S _the backyard mechanic ER try the following pro cedure for installing those plugs N m Thoroughly clean the gasket seat ing Space m Screw the plug in by hand as f r as 3twill go Carefully fit a deep of the proper size over the plug and pull on the wrench lightly until you feel the gasket beginning to compress m Slowly inerease the pull on the Secure until you feel the resistance become stiff indicating that the gasket has been fully compressed E Clean the ceramic insulator and top conductor with dry egrease free rag to prevent possible short
105. nue the disassembly following the step by step Instructions given with the kit and in a manual Since the different yoe and siles of carburetors vary greatly we can t cover the entire rebuilding process here However we will generally out line some of the major steps using pictures of a Rochester two barrel carb which is a rather common carb that is used on marly GM products Various carb rebuilding tips also ac ny the G pics e or holding the carb to the manifold can be removed and the carb lifted off the manifold retor and remove the float by pulling ane first step is removing the top of Checking the float is a very important step Remove ie by pulling the retaining a the carb air horn from the carb body pin Shake the float if there s gas in it you need a new one Remove the e el There is usually some linkages that must be inlet needle and seat and save them Remove the accelerator pump and other air unhooked to accomplish this This is the time parts according to instructions ores vee metering Valves The accelerator pump is an important part that shoots gas into the carb under OE easily los heavy demand A worn pump is what oauses lagging acceleration Soak the new 2 Don t get carried away When you re dis pump in light oil before installing itto be sure gt it seats correc
106. o one assembly located near the mias m ter cylinder arrow Older cars have sepa ex J rate valves located in the brake lines METERING VALVE DIFFERENTIAL PRESSURE n VALVE AND e ASSEMBLY continued THE BACKYARD MECHANIC pressure is at the proper level Like proportioning valves metering valves tarely malfunction However if the metering valve is not operating prop erly unusual Stress is placed on the gt front brakes reducing braking action and greatly increasing front brake wear p i Check the metering valve by dp ing the brakes very slowly engine rem 74920 Tf the metering valve is operating E e there will be a slight change in oe pressure at about one inch of travel it should feel like a slight bump H the valve is Hot o operating it can be easily replaced by disconnecting it from the brake line and carefully installing the new valve The brakes should be bled after installing the valve as mE System is Opened COMBINATION VALVES BOL fe s qq 1971 General S there is usually enough vacuum re TE maining in the system to give you 3 b duced valve that combines the Pe warning system proportioning and gt metering functions all in one unit Ford followed i in 1972 with the sa
107. oline about every oil change it does fairly good job of keeping the carb clean especially if you start from the time the car is new But this Meus type cleaner is not really too efficient at cleaning out built Up dirt and var nish D CLEANING KIT te The most effective method of clean 00 carb especially a gunky one without removing it from the engine lt 15 to run solvent directly into the carb E eyes ATE SS ees i n pu MEE E use of this Keep Mieres elean si DENM umm VOR eris ELE pe am i jeans carburetor pia bibi PPP 07 the manufacturer but they are all D essentially the same Tf you add a s Every sso often i I H i i i t v pt iP vo 2 3 MT LE 1 2 i 2 i inexpensive kits are available at most auto supply and discount houses and are quite simple to use After removing the air cleaner as sembly the first step in using the kit i to disconnect the gas line at the carb After carefully disconnecting the line being sure to catch escaping gasoline in a can or rag block off the gas flow with the special block off fit ting provided with the kit Then at tach the flexible solvent hose to the gas inlet on the carb using the correct _ size adapter from the kit Install the other end of
108. on tinue until no more air bubbles are forced from the cylinder on appli Cation of the brake pedal 5 Repeat procedure on remaining wheel cylinders Master cylinders equipped with bleed screws may be bled inde pendently When bleeding the Ben dix type dual master cylinder it is necessary to solidly cap one reser voir section while bleeding the other to prevent pressure loss through the cap vent hole Disc brakes may be bled in the same manner as drum brakes ex cept that 1 It usually requires a longer time to bleed a disc brake thoroughly 2 The disc should be rotated to make sure the piston has returned to the un applied position when bleeding is completed and the bleed screw is closed Check the master cylinder fluid reservoir regularly Before popping the top clean it thoroughly to keep gunk from contami nating the fluid A low fluid level may mean a leak inspect immediately failure But even df the system checks out okay it s a good idea to make a quick inspection of the hydraulic system as a preventive measure BRAKE LINES Although the master cylinder seems like the most logical place to start a hydraulic system inspection your best bet is to begin with the brake lines This if you have a leak it will be iso way lated to either the lines or the master cylinder immediately the master cylin der sometimes appears to he leaking w hen it s not
109. or mainten ance as often if they re kept clean Also because of the complexity and the emission control restrictions most regular mechanics do not attempt to rebuild many of today s carbs In most cases it s easier and cheaper to simply remove a faulty carb and bolt on a new or factory rebuilt unit The same is also true fer four barrel carbs many skilled mechanics find that it s easier to get a factory rebuild than trying to rework a 1 complex four bar rel carb So the fact that real do not try to rebuild all carbs ought to tell you backyard mechanics something Generally if you ve got carb problems with post 1970 carb or with any four barrelf nit you re probably better off getting a rebuilt one and installing it rather than fool ing with the old carb It s also illegal 4 gt Aerosol carb cleaners can be used to clean I i the outside of the carb and sprayed down the carb throat to clean the inside A t a for anyone but a certified mechanic to tamper with a newer carb in many Cases t So now you may be wondering just when should you rebuild a carburetor Well the main candidates for carb rebuilds are older cars with one and two barrel carbs If you re nursing along a car that s logged a lot of miles and is running a bit sick prob ably the best investment you can make is a reworked carb especia
110. ore beginning the tuneup how s 2 wo ever you should perform a compres s sion check Checking the compressi i Light carbon deposits should be scraped off the distributor cap contacts Heavy d carbon build p or cracks in the cap call for a new Gap On If you have compressed air avail able it s a good idea to blow out he plug d pressions to keep junk from falling in the hole when the plug is removed Pull off the wires on cou ple ef plugs and carefully remove the plugs Sirice the removed plugs will be j warny grab them with a rag or leave them in the plug socket tool to inspect them If the plugs have a crumbly chocolate brown deposit the engine is burning okay But if the plugs are black and oily either the plug is burn ing too cold or oil is leaking into t combustion chambers and fouling the Plugs oil fouling is common with older engines that have worn piston od rings In either case a hotter burning plug should be used On the other hand a white Powdery means R the engine is burning too hot and colder burning pus are definitely needed A good pl ce to buy new plugs is at a discount store But check the ap plication charts very carefully to get the correct plug for your engine Fre quently the same size engine uses a different plug depending on the year or horsepower rating o
111. own in other sys tems as the stator and reluctor timer core capacitor rotor and distributor shaft The distributor cap houses the ignition coil and is tasked with directing high voltage impulses to the spark plugs as in conventional systems A convenient tachometer engine Speed gauge connection is incorporated in the wiring connector on the side of the distributor except 77 models how ever it will activate only certain models of electric tachs better check with your Chevy dealer before you buy a tach for this system NOTE The ta EACH 1 2 TOOTH ERROR IS EQUAL TO 7 3 4 ENGINE DEGHEES TIMING ERROR Control module for amp Chrysler system is firewallmounted and has pir connectors for ease of replace U shaped de 77 vice is heat sink for transistor in center Heat is the enemy of solid state devices 50 if a module goes bad rapidly move the new one to a location not so near the engine or where a flow of cooling air is available Ballast chometer terminal on the distributor cap must never be grounded since grounding can damage the circuitry of the control module Wheh making com pression checks disconnect the igni tion switch connector from the system The wiring used with HEI is a carbon pow d impregnated fiber glass conductor en E MU contact panis ca
112. park plug wire Connectors One nice thing about the new ignition systems is that it s pretty difficult to hook them up incorrectly aft n the last BYM Back to Basics we covered the operation of the conventional or Kettering igni tion syst m We showed that the purpose of the ignition system was to develop high voltage timg the high voltage de livery with respect to engine speeds then direct the voltage to the rect spark plug Today s ignition systems DS exactly the same thing but they do it with greater accuracy higher Speedy and generally less components No Points It was long hoped that eventually an ignition system could be designed so thatthe contact points com to the Kettering system could be eliminated The need to eliminate points was caused by several reasons One points wear out quite Apidly consider ing the life of other automotive compo ru nents Two at higher engine speeds conventional points tend bounce that is they stay in the open position when engine and therefore distributor shaft speeds are high the points just do not have enough spring tension or enough time to close Three the rubbing block a fiber d vice attached to the points wears quite quickly As it wears dwell changes Along with the change in dwell rubbing block wear will not allow the
113. part of the plug is the tip of ithe nose the part that actually sits in the combustion chamber Heat flows up through the insulator down through the shell The longer the J heat path through the insulator and the hotter the plug and vice versa because the amount of heat that flows decreases as the length of the path is increased The cold plug when used in an engine has a tip which is actually colder than the tip of plug Thus the cold plug is recommended when the car is driven at full throttie most of the time Un fortunately this cold plug will tend to foul become covered with misfire causing deposits at low speeds be cause it is not hot enough to burn off deposits The fouling may be burned off if the period of low sp ed driving is short but long periods of operation will bake the deposits on and permit current to leak across the fouled insu lator especially during open throttle operations Eventualty the deposits become heavy enough t allow all the current to flow through the instead of across the air gap Conversely the hot plug will not foul when driven at low speeds but if itis driven continually at high Speed it He tip of the in sulat r will burn away s will pomon of the electrode 1 Proper Plug Installation The spark will become so hot that t plug gasket is importa
114. place making sure the guide hole is over the guide post and snug down the set screw Don t tighten it all the way because you still have to adjust the points Vv To adjust the points you have tog first get the point rubbing block on a lobe of the distributor cam see pho To do this turn the engine by hand with the fan or if your car has a clutch operated fan you can have a buddy tap the starter until the rub bing block is on the peak of a cam lobe and the points are open Now with the points held open by the cam carefully insert a clean feeler gauge of the correct size your man ual gives the gap spec in between gt the points Insert a screwdriver in the special adjusting slots see photo and adjust the gap until the gauge drags lightly when inserted the gap Then carefully tighten the set screw and double check the gap The frequently changes when the Screw is tightened Install the new rotor by lining up the guide inside the rotor with the groove on the cam and twist the rotor slightly unil it slides all the way down on the cam Re in stall the distributor cap and you should be all set The engine should fite up If not go back and check your work espe cially the point gap If it s too narrow or too wide the engine won t start The points should also be checked with a dwell meter As previously mentioned this will be covered nex
115. points to open to the specified dimension and will cause them to burn more easily Early attempts to eliminate points resulted not in point elimination but in reduced voltage carried by the points Transistor ignitions solved the problem of point burning and wear but didn t solve the other problems inherent in _ contact points Th mid sixties begin ning of the end for the Kettering ignition as we know it New strides in electronic technology enabled manufacturers to develop break rless high energy igni tion systems that did away with the problems associated with conventional ignition systems Not only are the new ignition systems more reliable than conventional systems they deliver higher energy levels they are easier to work on and they have become the first link in a chain along with carburetion and exhaust that will allow us to arangie harmful exhaust emissions Transistor Ignition As we mentioned earlier transistor X sistor ignition was the first attempt to really improve the Kettering system Transistor systems have some advantages to the Backyard Mechanic because they can be easily installed in any conventional system and really do increase point life good aftermarket transistor system will also increase voltage levels and thereby more fully combust the fuel air mixture with a resultant slight increase in power and mileage How It Works A
116. r Conditioning unit ere the simple principle that when a liquid is NE through the evaporator Toe ar then passes into the passenger co partment through those grilles you Rnow the ones we mean those little vy no matter where you aim them they still The R 12 boils inside the evapo dioi E and then passes into the compressor as a Yas where its pressure is inefeased R 12 pressure as it leaves the car s radiator The high pressure 3 com pressor is usually 200 psi Th R 12 then enters th heat exchanging coil resembling radiator usually located front caused by the compressor is put to work at this point and raises the boiling point ofthe R 12 to over 150 degrees F When 4 and fins of the condenser it cools and changes the R 12 back to a liquid losing i the heat it picked up from tHe interior of the The iquified R 12 then enters insu re ceiver dryer a small black tank located next to the condenser or on one of the fender wells This unit has the job of separating liquid refrigerant from any gas that might have left the condenser and also filters the refrigerant ab Sorbs any moisture it may contain It incorporates a sight glass in most Sys tems that allows the R 12 to be N checked for
117. r Ifa wheel pull r is needed you should be able to rent or borrow one from the parts house where you are getting your parts After removing both drums imme diately check the linings and drums for wear If the linings are worn past V amp inch they should definitely be re placed Jf there is plenty of lining rough up the lining with fine sand pap r and clean the assembly with alcohol before reinstalling the drum Tf replacement linings are needed the MACHINE WORK best bet is to stick with good quality asbestos bonded brake shoes While relined shoes are a little cheaper YOQUT brakes are only as good as the jini gs So the small amount saved on cHeap er linings isn t worth your safety Th brake drums should be cleaned and checked for warping and heat discoloration If the inside surface of the drums have grooves or Bienes large enough to catch a fingernail the Nm E drums should be turned iene is Brakes are adjusted pu using brake Spoon or 8 RES m 2 screwdriver to turn star wheel on adjuster Us As Po X ontinued screw Job is faster if s lt adjusting lever is 18 gt i released as ug MUS 2 co a E Ta The drum should slide off with brakes released However Clean th ved drums with denatured dlcohol and Check on some cars a wheel puller
118. rawn so that the two center plugs are fouled This suggests that raw fuel is being boiled out of the carburetor into the intake manifold after the engine is shut off If the engine is used for stop start short distance driving the two center plugs may foul Proper due to an overly rich diet carburetor float level good needie and seat seal and the addition of a layer of insulation between the carb base and manifold can help relieve this problem An unbalanced carburetor may pro duce fouled plugs in an 8 cylinder en gine as shown in Fig 3 A good look at the fuel flow on this particular design consult your Mitchell s or Motor Man uals sho t if the right barrel was running rich the cylinders it suppties would foul The remaining four would show normal plugs Finding the back four plugs ver heated as in Fig 4 may indicate cool ing pron apm There s a geod chance that_a_gc6d cleaning of the Boling sys gt tem would restore circulation to the rear of the engine One overheated plug Fig 5 can indicate a leak in the intake manifold near the location of the fouled cylinder Also check the firing order If the over heated plug is the second of two ad jacent consecutive firing plugs you could be the victim of cross fire Fig 6 shows a condition you m y See occasionally in larger V 8 engines us d for light duty two rear plugs are oil fouled Af t
119. re tight especially at the starter Filter A dirty air filter re stricts air flow to the carburetor and causes i to burn more gas So a clean air filter is essential for best mileage Most cars USE a MECHANIC bright light bulb light coming through all the way performing any maintenance And any jobs that the backyard mechanic feels are beyond his capabilities should be ler to experts e He posable paper demen filte available f r around 3 at stores You can check the by holding it up to the sunlight or to a If you can t see around the filter it should definite ly be replaced Gas Filter A plugged gas filter can stall your engine cold without warning Since there s no way to check the filter it s should be r placed at every tuneup here are two basic types of gas filters the type used on most GM products Rochester carbs installs inside the carb Most other cars use an in line filter that clamps the fuel line between the fuel pump and carb Do The GM type filter can ber placed by very carefully removing the fuel line at the carb while hold ing a rag under the lin connection to catch leaking gasoline When you remove the line note how the filter and spring insert in the filter hous ing so you can install correct yi pecial cleaning tool works
120. red complete by any means should help make sure mV don t buy a dog One thing to keep in mind is that not all of these checks apply to a clunker as much as to a new cat and vice verga A final point con cerns buyi g an imported car Since some of the wert exotic import cars have syncracies that you ight not be aware sf it s not a bad idea to have an import car checked out by a foreign car mechanic gt GENERAL CONDITION Begin checking out a car by simply walking around it looking for obvious i defects such as cracked window glass You should be able to get a good feel for whether the car had a hard life by T simple observation If the car has been j to check underneath it for splotches of liquid sitting for awhile be sure that indicate transmission rear end or cooling system leaks Check the tail pipe if it is oily or gunky the engine has internal problems Carefully eyeball all major body panels for ripples irregularities that indicate the has been pressed out after a crunch A once smacked car is best avoided since it could have suffered other Mapa in the crash When eyeing the body its a good idea to check the rocker panels for rust Although it s rare on a late model car rust could be starting O an older car rustmay have been painted over so check the paint for pitting Also check the splash
121. s are hvdraulically activated they may not know exactly why or how But the reason vour brake system op 2 5 erates with uid pressure involves on disc brakes even though st get your s stem E gt basic law of hydraulics simple that is quite Essentially a fluid cannot be compressed by pressure and is therefore an excellent transfer medium Fig gt J page 24 Since your cars brake sysem is basic ally airtight network of cylinders and lines filled with fluid what this means is that when you step on the brake pedal and create pressure in the m the pressure has to co some where If the brake syst m Is jn good working condition the pressure ends up at the wheel cylinders or pistons on disc brakes where it i relieved when the cylinders or pistons expand and force the brake linings against the drum or disc AS lene as you hive brake lining and an airtight hydraulic system filled with have you re going to stop But if vou a leak in the system that allows the pressur to escape before it reaches the wheels you won t step so ggod And if vou lose enough fluid or d enough air in the system you won t stop at all ae c as we ve all seen on the tube when the bad guy drains the fluid from the master cylinder of the good guy s car SYSTEM CHECK So if you want to keep stopping you shou
122. s p os rusty and gunky you probably better look for anoth r Also look carefully for any sign of oil in the coolant that would indicate cracked block and a definite no pur chase Make sure the brake easier cylinder is topped off and there are no signs of leaks around the unit If the car has Des problems i an automatic transmission pull the transmission dipstick and check the color and condition of the fluid It should be sparkly red If it is orange black has carbon specks or smells like varnish the transmission is in definite need of an overhaul Pull the PCV valve out and see if it clicks freely if it does the owner probably kept up on fe Tailpipe should be dy it is black gunky or oily the engine probably has internal Zo z z regular maintenance Finally just check around under the hood is the battery clean are the terminals clean and uncorroded INSIDE a If aias look good under the hood you can check out the inside of the car w and cables First look for lube stickers on the inside Do amp oc Of the door 7 service sta a tions put there to tell when the car was 6 serviced These indicate how well the kept the serviced unless he did his own maintenance and you might be able to match up the mileage on the odometer with that shown on
123. sed in mm silicone rubber jacket RON s c s As in the Dura Spark system the p IU HEI is magnetically controlled so it s charge ignition Uses theory ef operation is the same CDI One of the most popular after market ignition systems is the CDi or Capacitive Discharge Ignition The CDI operational theory is extremely compli cated and lengthy so we won t go into it here Suffice to say that CDls are dif erent ini theory and produce different esults than transistor or magnetically m ontrolled electronic ighitions Mag tems won t work with any contemporary netically controlled ignitions produce a aftermarket ignition wima relatively long lasting spark that gives extensive rework complete combustion and therefore low If you own an older car with conven emissions The CDIs produce a short tional Kettering ignition then the after lived voltage of extremely high amplitude market systems are for you Transistor 40 000 volts that is capable of firing systems work well on the family car and spark plugs under difficult conditions relatively inexpensive CDIs cost uch as fouled plugs or extremely high more but their performance is what you ompression need if you have an older truck Remember a CDI system points hat has a slightly tired engine or that are retained but they carry far less gt you use to carry or tow heavy loads urrent than they do
124. shoes arced Arcine the linings is simply machining them so they fit the drum a Using a special brake spring tool carefully remove the primary and secondary return X _ springs from the shoes If you do not have the special spring tool you can use vis 3 i grips to pop the springs off But us extreme caution with either tool because the more closely This eliminates the nor springs can pop leose at dangerously high velocities Check the springs for wear and mal lining wear in period However damage and place them in an appropriate container If you ve had problems with z ENT oe a dragging or n isy brakes you might consider replacing these springs especially if arcing is not necessary unless the they are worn corroded or weak aa drums are turned fe n E After removing the springs carefully release the self adjuster unit Tollowinig the in structions in your manual Next release the parking brake cable and remove the old shoes Disconnect the parking brake lever from the removed shoe so it can be in stalled on the new shoe Screw out the star wheel adjuster assembly and apply grease oF spray lubricant to the threads and reinstall it I 6 26 2 BLEEDER PISTO SCREW LA SPRING N The wheel cylinders are critical since they expand the brake shoes to operate the brake Check the cylin
125. slot usually on the batking plate behind the brake assembly While holding the self adjuster lever away from the star wheel as shown in the dia gram turn the Wwheel with a brak adjusting spoon or screwdriver until the brake is completely backed off Make sure the emergency brake is released when you loosen the brakes ed shoes If the linings are soaked with brake fluid you should also place the shoes in addition to xing the fluid leak I Its usually recommended that brakes both front and rear be in spected at least every 10 000 miles But rear brakes normally wear about twice as long as front brakes pulling the rear drums can be a hassle So if you know when the rear brakes e were last relined or checked you can get by with checking them every other atime you inspect the front brakes However a faulty automatic adjuster among other things rear linings to go fast and put a dan Berous strain on the front binders So don t hesitate to pull the rear drums at the first sign of any brake piob lems GETTING READY Because pulling the rear drums Can to make a foolproof record of how the assembled brake should look be a hassle you should be prepared to go ahead and do a complete brake _ job necessary when you pull the drums But since there s no way to tell exactly what parts and or service are required if any before you pul
126. solvent for soak ing the parts clean and you re about ready to go Remember never use gasoline for cle ning the carb since it is highly flammable But also be Careful with the carb solvent since it 15 very caustic and can burn your skin The best bet is to try to keep the solvent off your hands as much as possible rid always rinse the solvent off of your skin after long exposures to the solvent Besides common hand tools the only otlier items you ll need are some ye clean rags clean cans suchias coffee cans to use for soaking t tanks and E finally some sectioned pansz such as TV dinner trays for organizing parts Before beginning to work there are a couple of final points to keep in NU Se ae mind First don t forget to remove all jewelry and disconnect the nega tive battery cable positive cable ne on posi ive ground systems to pre 9 if ny chance of a burn or explo fron a spark Finally to make outside of the carb with solvent before beginning t The first step is disconnecting the fuel line vacuum lines and the link x ages so the carb can be lifted off the manifold never try to rebuild a carburetor on the engine Th import ant things are to be sure and use a container or a rag to catch the escap ing gasoline when y u disconnect the fuel line Also be sure you know ex
127. t month Now your car should a whole lot better But you re not finished yet The final settings of point dwell tim ing and carburetion are what make _ the difference between a car that runs that runs great So hang on til next month when we ll give you tips on supertuning p To adjust the point gap the rubbing block must be on a high lobe of the distributor cam Special rings that fit over the cam and hold the points open to the proper gap are available These save the trouble of cranking the engine to get the rubbing block 7 8 NERA With tne points held open by the cam the gap can be adjusted to specifications with l a feeler gauge The gap is changed ty inserting a screwdriver in the special adjust De Rule e eal s n SS ME m 2 EE DUM o backyaid mechanieing yeu can phe first step in final tuning X x ast month Backjaid Me hanic went through the basic tuneup steps of inspect ing essential components and install ing new ignition parts However we didn t get into the most important part of a general tuneup the final adjustments So this month we ll fin ish things off by outlining how to use the special tuneup equipment to make ihe imal tune settings The main items you I need for
128. t chamber in the vacuum advance mechanism and this causes the diaphragm to be moved against the spring This motion is trans mitted by linkage to the breaker as sembly Total vacuum advance is gov erned by the amount of vacuum in the intake manifold up to a limit imposed by the design of the diaphragm and linkage assembly Dwell Angle Dwell often referred to as contact angle or cam angle is the num ber of degrees of cam rotation during which the points r main closed It is during this period that the current in the primary coi winding increases Although the cam angle may not change the length of time the contacts remain closed decreases as engine speed increases At higher engine sp ds the ignition coil primary current doesn t reach its maxi mum value in the short length of time the points are closed In order to store the maximum amount of energy obtain able from the coil and thereby obtain sufficient energy to fire the plug a at will operate well at high speeds is necessary The distributor is equipped with a special high rate of break cam and a special high speed breaker lever which is capable of following the cam contours at high speeds without bouncing The high rate of break cam separates the points faster for each degree of rotation and permits closing earlier thus ef fectively increasing dwell Condenser The ignition condenser is a capacitor cons
129. t out that this is where the basic X S for buying a latd model car and a W nker vary For instance if you re checking out a late mol and you discover some minor going to have to pay to Y dollar for it But if you discover some robl lems and you re still interested in ft e car these problems might provide Some good bargaining points to encourage a private r in the owner to drop his price a bit case of a dealer you can be sure he guarantees to have these items repaired b fore the sale jou On the other hand when you Te buy ing arr older car especiall a clunker v yourmust expect the car int going to be in perfect condition And since you re V probably going to be b lying from a is it s impor fart thoroughly D lt and weigh how mucly you re paying against how much it will cost to get the e with a clunker private owner as is b tant to check out the car in shape Of course your main concern will be whether the is safe and reliable So the items you ll be most ncerned with are things like tires problems or a fairly major one you may want to write off the car especially if rakes steering and engine performa ce continued a WHEELS AND TIRES ip conti nued BUYING USED CAR 1 i i So the lowing basic checks while not to b conside
130. the h se to the can of E solvent and suspend it from the un fot less than 1 a can The prod cts AM derside of the hood Start the engine and run it at vary img speeds the solvent penetrates through all of the jets and passages briefly Place your hand over the carb to block the air flow to help force the solvent through the carb When all of the solvent has run through the carb the engine will die and the internal passages should be pretty well cleaned of gonik and varnish 2 To finish the job right carefully re 2 connect the fuel the enge and spray a c n of aerosol carb clean er decarbenizer down the throat of the carb following the instructions on the can The outside surfaces of the using a special gravity feed Kit These carb especially u al Fuel system cleaners to gas tank go by various product names Regular mo 3 symptoms like poor performance need of carbur tor rebuild or and carb is in geod Shape and the Gravity feed kits are the pest method of clean I ingt the inside of the carb 5 s so be sprayed clean with choke sol vent to keep things working right Also check for any gasoline leaks from the carb or fuel line when you clean the outside elg NOT FOR EVERYBODY i kj Now if you ve been having ak mileage sand
131. the presence of bubbles Remember this sight glass ut S in 5 valuable in troubleshooting ale probe Jems es el then flows through a liquid line i to the expansion valve This valve is y located Hear the evaporator rand 3 S usually on or near the firewall The valve through the evaporator heat and mois E n ture are removed shaped like a mushroom on some after ee market Systems controls the flow of R 12 N to the evaporator It provides only the amount of tlow that the evaporator can V handle SYSTEM TROUBLESHOOTING OE EE I L COMPRESSOR BELTS fnspect belts for cracking fraying or glazing Glazing can result from and result in slipping A glazed belt will have smooth slippery surface where the belt contacts the pulley If the belt needs replacing do so being sure you use only the belt spe F cified in your owners manual If your compressor is driven by multiple fa but only one is bad pa a both Belt sels are exactly that Sets A Replacing belts Loosen the ne mou ing bolts of the compressor and move the unit toward the fan so that the ig belt may be installed without prying _Check first though to see if you can qe plate the belt by loosening the idler pulleys instead of the compressor de Tighten th
132. tly MS assembling the carb Follow the instructions steprby step and don t tear down subassem NS a ME 450 blies unless specified in the instructions su X us I M photos continued on next page Finish dices commuting the carb according to instructions and organize all Tma i Darts ang the r 7 6 praviously zt mentioned you may have extra parts in the rebuild kit This is good time to main all l ne new parts with the removed ones atid get mgs organ nized for the reassembly continued THE E MECHANIC Soak all major parts in carb solvent for at least 30 minutes Do not place rubber plastic or any non metal parts in solvent they3may disappear These parts can be washed in solvent and rinsed clean After all parts have soaked clean rinse them thoroughly in water and let them air dry Here s a good example of why you should save all removed parts This carb uses two sizes of balls which could be easily mixed All new parts should be checked carefully against the removed parts be fore installation E Reassembie the carb following instruc tions Make all adjustments very care fully according to instructions if you don t all of your time and trouble has been wasted Float level is of the most important settings After installing reworked carb nd Hooking up all vacuum lines and linkages
133. transistor is a small electronic device that controls current via the conductive properties of an element known as germanjum The word transistor originates from the term to transfer resistance The transistor in an ignition system provides a means of furnishing greater current to the ignition coil with an ac companying larger secondary voltage for spark plug firing At the same time it supplies less current to the ignition contacts thereby prolonging their life This whole deal is accomplished by using two interrelated primary ignition circuit whereas the Kettering system uses only one such circuit continued _ E resistor the toroid The system consists of a base circuit ui low voltage trigger circuit coil primary collector circuit low voltage primary circuit and a secondary high voltage coil circuit Current will not flow in the primary circuit unless a current is flow ing in the base circuit A very small current in the base circuit allows a much larger current flow in the primary col lector circuit In actual operation see Fig 1 a amp current flows from the battery through the ignition contacts a common 33 ohm resistor the ignition Switch and back to the battery This small current flow let s call dt control current permits a large 12 amp current to flow from the battery through the ignition coi
134. ts nearly all other cars In line filters Fhe PCV filter is located in thes rocker arm cover or intake manifold on most cars and should be replaced at every tuneup E connected at the air cleaner ad manifold and that it s not leaking Spark Plug Wires Plug wires are very frequently neglected items that can cause plenty of problems Wires with cracked or damaged insulation should be replaced The best way to install new wjres is to buy a replace ment kit designed for your car problems Locate the heat riser the exhaust pipe ortcrossover near the exhaust manifold and check for free operation A sticking valve can be freed with solvent Most cars since 1971 and many older mod l cars have a Sp cial thermostatically controlled air Cleaner instead of the heat riser few Cars still use both Sys e gine These kits come with wires pre cut tothe proper size The only trick is replacing one wire at atime so you get the wires into the dis tributor cap correctly If the wires are oilisoaked but not they can be cleaned with solvent Clean Carb At every if not more frequently a can of carb gt _combustion chamber cleaner should tems If yGur car uses a thermo air cleaner there will be a hot air tube ot pipe rurining from the exhaust i man
135. tuneup is a quick inspec tion ofthe basic Components that affect reliability and performance some of the most important checks that require nothing more than a couple of minutes and common tools are listed below Battery First after removing any jewelry pop off the battery filler Caps and check to see that the wa lt ter level is up to the fill line or over plates in all cells Ifthe level is E The Backyard Mechanic is designed to serve as only a general guide to the maintenance topics discussed Since Basic procedures vary from car to car a manual should be consulted when low bring it up with distilled water Tap water is okay in an emergency Next make sure the battery case and terminals are clean Corroded d with steel wool or a special cleaning tool such as pictured When removing the battery cables for cleaning terminals should be sufe to remove the ground cable first the cable that runs to the car frame or engine the negative cable on nearly all American ey most imports Connect t und last when reinstalling the cables A dirty battery case can be washed with baking soda solution and rinsed with clean water Coat the tops of the cleaned battery termi nals with petroleum jelly to help prevent corrosion Finally trace the Positive battery cable to make sure all electrical connections a
136. vacuum gaifge The yacuum gauge should show at least 16 inches of mercury with the engine idling Although not very common if vag uum is low at the intake manif ld 1 5 probably because of vacuum leaks You can check for leaks by putting heavyweight oil on the joints at the 2 carburetor base and intake manifold If there is a leak the oil will seal it T temporarily and the engine speed will increase Leaks can be repaired by tightening the bolts or installing new gaskets if necessary ee Jf there is plenty of vacuum at the hose but the booster unit still doesn t work the vacuum check valve s see picture is usually at fault This valve is common cause of power brake _problems The check valve is a One way unit that allows air 4 775 be sucked out of the vacuum boos ter to operate the assist but doesn t let air back i in vacuum out when the engine is shut off If the valve comes loose or fails vacuum isn t maintained in the booster unit and the power assist can t operate Most check valves can be easily removed from the vacuum unit for in spection Carefully pull or unscrew the valve from the unit and discon nect it from the vacuum line Test the valve by blowing through it one way and then the other You d Bntinued e PEE continued JOVE THE BACKYARD MECHANIC should be able to blow through the 1 end that inserts
137. ve passes air bl from each direction it s faulty MOVE HANDLE UPWARD RETRACT shoes 770707 AUTOMATIC ADJUSTER CHECK 1 Raise the vehicle and support it prop erly with safety stands Chock the wheels 2 Loosen the brakes by holding the ad juster lever away from the starwheel an backing off the starwheel approximately 30 notches see diagram Spin the wheel and brake drum in verse and have a hetper apply the brakes The movement of the secondary shoe should pull the adjuster lever up when the brakes are released the lever should snap down and turn the star wheel E 4 4 1f the automatic panicles doesn t ie work the drum must be removed and the ad juster components inspected carefully for wear improper installa 5 tion 2 The Bagkyard Mechanic is designed the maintenance topics discussed Since basic procedures vary from sulted when performing any main backyard mechanic feels are be _ to experts to serve as only a general guide to 15 a manual should be con tenance And any jobs that the yond his capabilities should be ien E few years ago a major oil comi ter knowr as purpose of the ad was to con s vince you to use their detergent gaso i line to keep Mr
138. w the wires fit into the cap Tf the distributor cap is in good condition gently scrape any carbon off the contacts with a screwdriver and spray out the inside of the cap with solvent Wipe the cap clean with _ and pull it out of your way _ There are basically two types of distributors and the procedure for in stalling and adjusting the points dif fers We ll discuss the two types sep companying pictures should get you oriented jf you ve never replaced ig nition parts Magneti ed serew stalling new ignition points con denser are the only tricky parts of a funeup but even this job is simple While some people recommend removing the dis Most GM cars have caps with a spe Most other type caps ar theld i in place arately beginning with the type used on nearly all GM products The ac condenser photo unless you have a window radio will be a shield over the points that N n GM distributor GM DISTRIBUTORS On a GM type distribtuor the T thing you ll see with the distributor cap removed is a large round rotor held in place by two screws Loosen the screws and lift the rotor straight up to remove it Now the points and should be visible see antenna in which case there you Simply pull off Now you can see that the points condenser are held in place by set screws
139. wood under the brake pedal to prevent accidentally depress k E ing the pedal something which Can cause real problems when the brakes are disassembled REMOVING THE DRUMS When you re ready to get into things the frst step is removing the brak drums The same type drum brakes have been used on all Ameri can cars except Vega since 1970 and on most cars since 1966 so the pro cedure is basically the same for new er cars Generally all that s required is backing off on the brake adjustment SO he drums can be pulled free To do this first remove thef rubber plugs that dover th brake access slots usually located on the backing plate behind the brake assembly Some cats have a filled access slot that will have to be punched out to gain access to the adjyster Insert a brake adjusting tool costs about 50 cents or screwdriver in the slot Then while holding the auto matic adjuster lever away from the star wheel with a small screwdriver turn the adjuster up until the drum turns freely see diagram Give the adjuster four or five good turns to make sure the brakes are completely backed off j If the drum won t budge after loosening the brakes you may have to use opel puller Check your i MOVE HANDLE UPWARD TO RETRACT BRAKE SHOES manual for the specs on your ca
140. y cause misfire Could mean engine may need valve guide seal o left Caused by deposits loosened from hot pi engines are most usually affected by gap bridgin high heat in th combustion chamber Try a plug is one step colder ws lee a reignition is a no no It s caused by combustion chamber deposits which become incandescent and ignite fuel before the plug does Other causes include piston scuffing detonation cross firing or plug heat range too high i Overheated plugs have a blistered white jnsulator and very few deposits Check f r correct plug heat range overadvanced ignition timing cooling system malfunc tion leaking intake manifold or sticking valves V C ton top and splashing onto insulator Just clean and regap centery Two stroke motorcycle AN Caused by dirty air filter or dirty piston top right Insulator glazing occurs because of Cross Fire Although it is not a spark plug problem cross fire is an ignition problem that can cause trouble Cross fire or induction leakage can occur whenever ignition cables are grouped closely together and run in parallel for gome distance Cross fire isn t usually caused by faulty cable insulation but by the magnetic field which surrounds any high voltage conductor The lead which is carrying high voltage at any given instant tends to induce voltage in an adjacent lead Cross f
141. y will go awfully long time before major maintenance is needed Quality All oil cans are supposed _ to be labeled with a code which indi For use oil graded at least SD Service Deluxe Newer cars re quire SE Service Extreme quality Most premium quality oil will pro vide adequate engine protection so the choice of brands is personal pref erence If you do decide for somerea to switch brands be sure that you continue to use tlie same type cates the Oil s service limitations detergent or non detergent and rating SE or SD that you have been thing Most good quality oil filters s about the same but be sure that whatever brand or type you choose it Meets the car manufaqtur r s specifi gations and warranty requirements fternal additive supplies Lately we ve seen the development of two stage filters and filters with in Both new types appear to be well tested and reli able and seem to have gained aceept ance with the professional racer crowd These new type filters are not too much filters and the added protection they offer may be worth the increase in price over single stage c nv ntional filters Additivgs Basically if you use a high quality oil and change it reg ularly you don t need additives Army studies indicate that the vast majority of those additives tested by the Army don t add muc
142. you can fire B the engine and adjust the fuel mixture and idle speed as specified in the manual _ es Soon as you get the engine running right why ative to a good shop and jet the carb Scientifically adjusted right with the special analyzers This will insure you re getting the best performance and mileage with the lowest emissions After all the ee you ies saved by doing yonr own carb rebuild you can Surely afford iL po Nowthatwe ve got the direi warnings let s take a look your car s air conditioning system to see how it works 1 maybe we can clear up a few mal Lo functions 07 UIT URS ADEL OPERATING THEORY 3 a TE hose of you who are familiar gt with T O s know that during cer 2 dain portions of any operation there are little notes that read caution or warning Well right up front here s sa warning about foolin Around with your ap oir conditioner ab converted to a gas it absorbs heat from its surroundings Using an immense amount of logic we see that when it s feconverted from a aces paee Slew O cigarette Or ds to a liquid it gives up this heat U In order to accomplish this feat of heat ee removal need Several components They are the compressor the E the receiver the expansion valve the evapor

1 - Pole Shift Survival Information

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