BENDIX BW2234 User's Manual
Contents
1. Test for excessive system leakage Allowable leakage observed at dash gauge Single vehicle 1 psi minute Tractor trailer 3 psi minute Using soap solution test vehicle for leakage at fittings drain valves and system valves and any accessories i e air suspension connected to the Bendix AD IS air dryer auxiliary ports If an accessory is suspected to be the cause of leakage disconnect that accessory from the air dryer plug the auxiliary port that it was in and retest the AD IS air dryer for proper purge cycling Repair or replace as necessary Build system pressure to governor cut out Wait 1 minute for completion of purge cycle Using soap solution at exhaust of purge valve leakage should not exceed a 1 bubble in less than 5 seconds If a rapid loss of pressure is found the following procedure will determine if the delivery check valve is malfunctioning Build system pressure to governor cut out and allow a full minute for the normal dryer purge cycle to empty the purge reservoir Switch off the engine and fan the brakes so that the system pressure reaches governor cut in The purge valve will return to its closed position The purge reservoir has a drain valve which is opened by moving the center lever away from its closed position Open the drain valve and wait 10 seconds to allow any residual purge pressure to be released Release the lever closing the drain valve Carefully remove the air dryer cartridge2. and Reservoir Systems RES GOVERNOR RESERVOIR 2 PURGE VALVE DESICCANT CARTRIDGE STANDARD SHOWN GOVERNOR PRESSURE PROTECTION VALVES 4 PURGE RESERVOIR Bendix AD IS and AD IS PuraGuard Oil Coalescing Air Dryer SD 08 2418 DESICCANT CARTRIDGE PURAGUARD OIL COALESCING SHOWN MOUNTING HOLES 4 23 AUX2 AUXILIARY DELIVERY PORT UNL GOVERNOR UNLOADER 2 BOLTS 3 22 SEC DELIVERY TO SECONDARY HEATER NN RESERVOIR THERMOSTAT 24 21 1 AUX1 PRI EXH AIR DRYER IN AUXILIARY DELIVERY TO PRIMARY GOVERNOR PARTNUMBER SUPPLY FROM PRESSURE PROTECTION DELIVERY PORTS RESERVOIR EXHAUST STAMPEDHERE COMPRESSOR VALVES 4 4 FIGURE 1 BENDIX AD IS AND AD IS PURAGUARD OIL COALESCING AIR DRYER AND RESERVOIR SYSTEMS The function of both the Bendix AD IS Integrated Solution Port ID Connection Air Dryer air dryer and reservoir system and the Bendix M Inlet Port air in AD IS PuraGuard oil coalescing air dryer and reservoir system is to collect and remove air system contaminants E Delivery Port Out to Primary Reservoir in solid liquid and aerosol form before they enter the brake T7 system and to provide as a module heavy vehicles with SEC Delivery Port out to Secondary Reservoir an integrated vehicle air dryer purge reservoir governor 24 p and a number of the charging valve components in a AUX 1 Auxiary Delivery Port Vell Qui module These components have
3. Every 900 operating hours or 25 000 miles or three 3 months 1 Check for moisture in the air brake system by opening reservoir drain valves and checking for the presence of water If moisture is present the desiccant cartridge may require replacement however the following conditions can also cause water accumulation and should be considered before replacing the desiccant A An outside air source has been used to charge the System This air did not pass through the drying bed B Air usage is exceptionally high and not normal for a highway vehicle This may be due to accessory air demands or some unusual air requirement that does not allow the compressor to load and unload compressing and non compressing cycle in a normal fashion Check for high air system leakage If the vehicle vocation has changed it may be necessary to upgrade the compressor size Refer to Bendix Specification BW 100 A Appendix D to determine if any changes are necessary Specification BW 100 A is available from the Bendix TechTeam at 1 800 247 2725 or www bendix com C The location of the air dryer and reservoir system is too close to the air compressor Refer to Bendix Specification BW 110 A Appendix B for discharge line lengths D In areas where more than a 30 degree range of temperature occurs in one day small amounts of water can temporarily accumulate in the air brake system due to condensation Under these conditions the presence of
4. GASKET SEE ASSEMBLY NOTE 6 GOVERNOR SMALL O RING SHE NIE SPRING NON ADJUSTABLE 130 PSI CUT OUT Tre n LARGE O RING ADAPTER FIGURE 6 BENDIX AD IS AIR DRYER AND RESERVOIR SYSTEM DELIVERY CHECK VALVE ROADSIDE INSPECTION In the event of a roadside inspection the system behavior will be as follows When the system is charged to governor cut out and then one reservoir drain valve is opened initially both reservoir gauges will fall however the Bendix AD IS air dryer primary and secondary pressure protection valves will close at pressures above 70 psi protecting the remaining brake circuit from further loss of pressure TEMPORARY AIR DRYER AND RESERVOIR SYSTEM BYPASS To temporarily bypass the air dryer follow these procedures Adhere to the General Safety Guidelines outlined elsewhere in this document Make sure that all residual pressure has been released and the air dryer purge reservoir has been drained to 0 psi then remove the air supply line from the compressor to the inlet port 1 IN Remove the safety valve from the Bendix AD IS air dryer see Figure 1 for location Note that a short puff of trapped air may vent from the safety valve port when removing the valve Install a T fitting into the port Using any adapters necessary reinstall the safety valve in one of the branches ofthe T fitting Using any adapters necessary install the air supply line into the remaining T fitting port A
5. IS air dryer and reservoir from the vehicle 1 Remove the line from the governor and mark for easy re installation Remove the bolts attaching the governor to the AD IS air dryer and reservoir system and retain for re assembly Remove the governor from the air dryer Be aware that a short puff of trapped air may vent when the governor is removed Retain the governor gasket for re assembly if a new governor gasket is not available Remove and retain the o ring from the adapter 4 The spring delivery check valve can now be removed Remove and retain the o ring from the check valve body CLEANING amp INSPECTION 1 10 Use a suitable solvent to clean all metal parts and use a cotton swab to clean the bore Note Do not use abrasives or tools to clean the bore any scratches caused may necessitate replacing the Bendix AD IS air dryer and reservoir system Superficial external corrosion and or pitting is acceptable Clean the o rings with a clean dry cloth Do not use solvents Inspect for physical damage to the bore and the check valve seat If the bore is damaged by scratches etc that would prevent delivery check valve from seating replace the AD IS air dryer Inspect the delivery check valve o rings etc for wear or damage Replace if necessary using the check valve replacement kit available at any authorized Bendix parts outlets Inspect all air line fittings for corrosion and replace as necessa
6. Replacement Kit 5004049 Governor Gasket 5007834 Heater amp Thermostat Replacement 12 volt 109495 Heater amp Thermostat Replacement 24 volt 109496 E I A R Bendix PuraGuard Oil Coalescing Desiccant Cartridge K020366 Service New Kit Mounting Bolt Kit 5009233 Protective Boots for pressure protection valves 5005163 Safety Valve 800350 Splash Shield Kit includes bracket and cover 5006698 Splash Shield Cover 5005266N Silencer Kit K021189 Wiring Harness amp Splice Kit 109871N Purge Valve Assembly Type Configuration Service RUE Pc No Bendix AD IS Air Dryer K022105 G6 Purge Valve Assembly for AD IS EverFlow K031560 climate conditions above Module 40 C 40 F AD IS Discharge Line K031562 Unloader AD IS Air Dryer K031559 Arctic Purge Valve Assembly Tico for climate conditions of AD Pa K031561 40 C to 50 C 40 F to 58 F AD IS Discharge Line K031563 Unloader 4 tis recommended that the total air system be tested for leakage to assure that the AD IS air dryer and reservoir system will not cycle excessively BRAKING SYSTEM PROTECTION The AD IS air dryer allows the system to maintain one brake circuit up to about 100 psi even after a pressure loss in the other brake circuit This allows a vehicle to be moved in an emergency but with reduced braking capacity Compare this to a conventional system where a loss of pressure in one service tank leaves the vehicle with a limited number of
7. air dryer and reservoir system Similarly the governor also supplies air pressure to the air dryer The pressure also moves the air dryer purge piston down opening the purge valve to atmosphere and closing off the compressor air supply to the turbo cut off valve covered in the Turbo Cut off Feature section of this piece Water and contaminants captured are expelled immediately when the purge valve opens In addition air which was flowing through the desiccant cartridge changes direction and begins to flow toward the open purge valve Contaminants collected by the air dryer are removed by air flowing from the purge reservoir through the desiccant drying bed to the open purge valve The initial purge and desiccant cartridge decompression lasts only a few seconds evidenced by an audible burst of air at the air dryer exhaust The actual regeneration of the desiccant drying bed begins as dry air from the purge reservoir flows through the purge orifice into the desiccant bed Pressurized air from the purge reservoir expands after passing through the purge orifice its pressure lowers and its volume increases The flow of dry air through the drying bed regenerates the desiccant material by removing any water vapor adhering to it Approximately 30 seconds are required for the entire contents of the purge reservoir of an AD IS air dryer and reservoir system to flow through the desiccant drying bed The delivery check valve assembly prevents
8. air pressure in the brake system from returning to the air dryer during the purge cycle After the purge cycle is complete the air dryer and reservoir system is ready for the next charge cycle to begin TURBO CUT OFF FEATURE Refer to Figure 3 The primary function of the turbo cut off valve is to prevent loss of engine turbocharger air pressure through the AD IS air dryer when the dryer is in the purge mode At the onset of the purge cycle the downward travel of the purge piston is stopped when the turbo cut off valve the tapered portion of purge piston contacts its mating metal seat in the purge valve housing With the turbo cut off valve seated in the closed position air in the compressor discharge line as well as the AD IS air dryer inlet port cannot enter the air dryer By completing these actions the turbo cut off effectively maintains turbo charger boost pressure to the engine PREVENTIVE MAINTENANCE Important Review the warranty policy before performing any intrusive maintenance procedures An extended warranty may be voided if intrusive maintenance is performed during this period Purge valve maintenance is permissible during the warranty period only when using a genuine Bendix purge valve kit Because no two vehicles operate under identical conditions maintenance and maintenance intervals will vary Experience is a valuable guide in determining the best maintenance interval for any one particular operation
9. exhaust port and observe that leakage does not exceed a 1 bubble in one second If any leakage exceeds the maximum specified refer to Symptom 4 in the Troubleshooting Chart 4 Build up system pressure to governor cut out and note that the AD IS air dryer purges with an audible burst of air followed immediately by approximately 30 seconds of air flowing out of the purge valve Fan the service brakes to reduce system air pressure to governor cut in Note that the system once again builds to full pressure and is followed by a purge If the system does not follow this pattern refer to Symptoms 5 and 6 in the Troubleshooting Chart 5 Check the operation of the end cover heater and thermostat assembly during cold weather operation as follows A Electric Power to the Dryer Refer to Figure 4 With the ignition or engine kill switch in the RUN position check for voltage to the heater and thermostat assembly using a voltmeter or test light Unplug the electrical connector at the air dryer and reservoir system and place the test leads on each of the connections of the female connector on the vehicle power lead If there is no voltage look for a blown fuse broken wires or corrosion in the vehicle wiring harness Check to see if a good ground path exists B Thermostat and Heater Operation Note These tests are not possible except in cold weather operation Turn off the ignition switch and cool the thermostat and heater as
10. in air D Replace air dryer pressure protection valves are not dryer will not open serviceable E Referto Symptom 4 E Referto Symptom 4 Remedy A F Referto Symptom 7 F Referto Symptom 7 Remedies A and B Air dryer does not purge or A Faulty air dryer purge valve A After determining air reaches purge valve control port by exhaust air installing a T fitting with a pressure gauge into the governor unloader port repair purge valve if necessary B See Causes B E and F for Symptom B Refer to Symptom 4 Remedies B E and F E NNNM Desiccant material being A Faulty dryer cartridge A Replace the Bendix AD IS air dor cartridge or AD IS air expelled from air dryer purge dryer valve exhaust may look like B Excessive dryer vibration B Check the AD IS air dryer mounting for looseness or damage whitish liquid or paste or Repair mounting and replace cartridge small beads Unsatisfactory desiccantlife A Excessive system leakage A Referto Symptom 1 Remedy A B Wrong vehicle application for AD IS B Refer to Symptom 2 Remedy C air dryer C Compressor passing excessive oil C Check for proper compressor installation if symptoms persist replace compressor Refer to Bendix Advanced Troubleshooting Guide for Air Brake Compressor BW1971 Pinging noise excessive A Single cylinder compressor with high A A slight pinging sound may be heard during system build during compressor loaded
11. pulse cycles up when a single cylinder compressor is used If this sound cycle is deemed objectionable it can be reduced substantially by increasing the discharge line volume This can be accomplished by adding a 90 cubic inch or larger reservoir between the compressor and the AD IS air dryer and reservoir system The air dryer purge piston A Compressor fails to unload Check air hose from governor to compressor for a missing cycles rapidly in the kinked or restricted line Install or repair air hose compressor unloaded non Repair or replace compressor unloader compressing mode 13 14 BW2234 2011 Bendix Commercial Vehicle Systems LLC a member of the Knorr Bremse Group 07 11 All Rights Reserved
12. L PRESSURE PROTECTION VALVES OPEN FIGURE 2 BENDIX AD IS AIR DRYER AND RESERVOIR SYSTEM CHARGE CYCLE The Bendix AD IS PuraGuard oil coalescing air dryer has an identical appearance to the standard AD IS air dryer but contains a coalescing media at the inlet of the desiccant bed The coalescing media provides a higher level of oil removal over the standard AD IS air dryer The AD IS PuraGuard oil coalescing air dryer has all of the same functions as the standard AD IS air dryer and is used in applications where lower oil concentration levels are required Important When servicing note that standard AD IS air dryers or air dryer cartridges may be serviced with PuraGuard oil coalescing air dryers or cartridges however PuraGuard oil coalescing air dryers or cartridges must only be serviced with like replacements Note Unless otherwise stated in this manual AD IS air dryer and reservoir systems refers to both the standard and PuraGuard oil coalescing air dryer and reservoir systems The function of the pressure protection valves is to protect each reservoir from a pressure loss in the other reservoir or a pressure loss in an air accessory Each of the pressure protection valves in the AD IS air dryer and reservoir systems may have different pressure settings These are factory set and must not be changed or adjusted The air dryer and reservoir system consists of a spin on desiccant cartridge secured to a base assembly T
13. NY work on the vehicle If the vehicle is equipped with a Bendix AD IS air dryer system or a dryer reservoir module be sure to drain the purge reservoir Following the vehicle manufacturer s recommended procedures deactivate the electrical system in a manner that safely removes all electrical power from the vehicle 6 T 10 11 Never exceed manufacturer s recommended pressures Never connect or disconnect a hose or line containing pressure it may whip Never remove a component or plug unless you are certain all system pressure has been depleted Use only genuine Bendix brand replacement parts components and kits Replacement hardware tubing hose fittings etc must be of equivalent size type and strength as original equipment and be designed specifically for such applications and systems Components with stripped threads or damaged parts should be replaced rather than repaired Do not attempt repairs requiring machining or welding unless specifically stated and approved by the vehicle and component manufacturer Prior to returning the vehicle to service make certain all components and systems are restored to their proper operating condition For vehicles with Automatic Traction Control ATC the ATC function must be disabled ATC indicator lamp should be ON prior to performing any vehicle maintenance where one or more wheels on a drive axle are lifted off the ground and moving GOVERNOR GASKET SPECIAL
14. been designed as an 23 Auxiliary Delivery Port air out integrated air supply system AUX 2 UNL Unloader Control Air D 2A Governor Both air dryer and reservoir systems provide clean dry air to the components of the brake system which increases RES the life of the system and reduces maintenance costs The necessity for daily manual draining of the reservoirs is eliminated Common Reservoir Pressure D 2A Governor TABLE 1 PORT DESIGNATIONS Note 1 The Bendix AD IS air dryer and reservoir system purge piston has a purge control channel drain This allows any condensation in this area to flow past a diaphragm in the top of the purge piston and out through a channel in the middle of the central bolt of the purge assembly to be drained During the purge cycle this drain is closed DESICCANT BED es a sual Lees baad as eee ee Se ee ee EESE d o oM J LO OIL COALESCING FILTER BENDIX AD IS PURAGUARD OIL COALESCING AIR DRYER PURGE PURGE RESERVOIR DELIVERY ORIFICE CHECK VALVE OPEN PRESSURE PURGE CONTROL CHANNEL GOVERNOR UNLOADER gt AN vaa uum PORT SUPPLY PORT PURGE VALVE CLOSED Loss SECONDARY ENGINE OPEN PORT SEC COMPRESSOR SEE NOTE 1 PRIMARY SAFETY PORT PRI VALVE PROTECTION VALVES A Q PURGE RESERVOIR fo DRAIN VALVE env C RESERVOIR SECONDARY RESERVOIR AUXILIARY PORTS TO ACCESSORIES DIAGRAM SHOWS AL
15. e designed to receive compressed air from the vehicle air compressor clean and dry the air deliver air to the vehicle s primary reservoir secondary reservoir and accessories and control the compressor dryer charge cycle AIR DRYER AND RESERVOIR SYSTEM OPERATION GENERAL The Bendix AD IS air dryer and reservoir system alternates between two modes or cycles during operation the Charge Cycle and the Purge Cycle The following describes these cycles of operation CHARGE CYCLE Refer to Figure 2 When the compressor is running loaded compressing air compressed air flows through the compressor discharge line to the inlet 1 IN port of the air dryer body The compressed air often includes contaminates such as oil oil vapor water and water vapor Traveling through the discharge line and into the air dryer the temperature of the compressed air falls causing some of the contaminants to condense and drop to the bottom of the air dryer and purge valve assembly These contaminants are ready to be expelled at the next purge cycle The air then flows into the desiccant cartridge where it flows through an oil separator or coalescing filter if equipped with a PuraGuard oil coalescing cartridge which removes water in liquid form as well as liquid oil and solid contaminants Air then flows into the desiccant drying bed and becomes progressively more dry as water vapor adheres to the desiccant material in a process known as ads
16. fter testing the T fitting for any air leakage by using a soap solution after charging to system cut out pressure a 1 bubble in 10 seconds is acceptable the vehicle may be returned to temporary service Note This is a temporary bypass of the air dryer Full repair of the unit must be carried out at the earliest opportunity With the air dryer removed from the system contaminants will be entering the air brake system reservoirs will need to be manually drained daily until the repairs are completed At the end of each working day park the vehicle and slowly drain pressure through the drain valves leave open to the atmosphere for several hours if possible When repairs are carried out be sure to check that all reservoirs including the air dryer purge reservoir are emptied of all contaminants If after bypassing the air dryer and reservoir system the system pressure still does not build use the following procedure to remove clean and reinstall the delivery check valve DELIVERY CHECK VALVE CLEANING PROCEDURE Note This is only required if system pressure does not build after temporary bypass is completed Refer to Figure 6 throughout the following procedures De pressurize the air brake system following the general safety precautions outlined elsewhere in this document Also always de pressurize the air dryer purge reservoir before servicing the air dryer This procedure does not require removal of the Bendix AD
17. he base assembly contains a delivery check valve assembly DESICCANT BED OIL COALESCING FILTER BENDIX AD IS PURAGUARD OIL COALESCING AIR DRYER Meh Peet PEEP ststst d 3 DELIVERY CHECK VALVE PURGE CLOSED CONTROL CHANNEL GOVERNOR UNLOADER PORT SUPPLY PORT PURGE VALVE OPEN j TURBO ay OFF japs COMPRESSOR EXHAUST VALVE SECONDARY PORT SEC PRIMARY SAFETY PORT PRI PURGE FURGE RESERVOIR ORIFICE PRESSURE PROTECTION VALVES O PURGE RESERVOIR DRAIN VALVE 5 C D SECONDARY RESERVOIR PRIMARY RESERVOIR AUXILIARY PORTS TO ACCESSORIES DIAGRAM SHOWS ALL PRESSURE PROTECTION VALVES OPEN FIGURE 3 BENDIX AD IS AIR DRYER AND RESERVOIR SYSTEM PURGE CYCLE safety valve heater and thermostat assembly pressure protection valves threaded air connections and the purge valve assembly The removable purge valve assembly incorporates the purge valve mechanism and a turbocharger cut off feature that is designed to prevent loss of engine turbo boost pressure during the purge cycle of the Bendix AD IS air dryer and reservoir system For ease of maintenance all replaceable assemblies can be serviced without removal of the air dryer and reservoir system from its mounting on the vehicle Refer to Preventive Maintenance section BENDIX AD IS AIR DRYER AND RESERVOIR SYSTEM OPERATION GENERAL Refer to Figure 2 The AD IS air dryer and reservoir systems ar
18. hould be an associated leveling off or momentary slight fall of pressure as the third and fourth pressure protection valves open Then the primary and secondary gauges should increase together until they reach their full pressure of approximately 130 psi 5 psi If the Bendix AD IS air dryer and reservoir system does not perform within the pressure ranges as described above recheck using gauges known to be accurate If the readings remain outside of the ranges outlined replace the AD IS air dryer and reservoir system NOTE There are no kits available for the servicing of the pressure protection valves Warning Do not attempt to adjust or service the pressure protection valves incorrect pressure protection valve settings can result in automatic application of the vehicle spring brakes without prior warning in the event one of the supply circuits experiences rapid pressure loss GENERAL When rebuilding or replacing components of the air dryer and reservoir use only genuine Bendix brand replacement parts For ease in servicing the AD IS air dryer and reservoir have been designed so that maintenance kits can be installed without removing the air dryer and reservoir from the vehicle CAUTION Always depressurize the air dryer and purge reservoir and all other reservoirs on the vehicle to 0 psi before servicing the air dryer It after completing the routine operation and leakage tests it has been determined that one or
19. more components ofthe air dryer requires replacement or maintenance refer to the Maintenance Kit listing shown in this manual or the Bendix Quick Reference Catalog for the appropriate kit s The Quick Reference catalog BW1114 can be ordered and viewed on line at www bendix com NOTE Kits are not available for the servicing of the pressure protection valves See Figure 5 Do not attempt to adjust or service the pressure protection valves these are not service items TESTING THE BENDIX AD IS AIR DRYER AND RESERVOIR SYSTEM Before placing the vehicle into service perform the following tests 1 Close all reservoir drain valves 2 Build up system pressure to governor cut out and note that the Bendix AD IS air dryer purges with an audible burst of air followed immediately by approximately 30 seconds of air flowing out of the purge valve 3 Fan the service brakes to reduce system air pressure to governor cut in Note that the system once again builds to full pressure and is followed by a purge at the air dryer exhaust Maintenance Kits Kit Description Piece No Delivery Check Valve Replacement Kit 5004052 Desiccant Cartridge Replacement Kit Standard 5008414 Desiccant Cartridge Replacement Kit Bendix AD IS PuraGuard air dryer can be used to replace the standard 5008414PG cartridge Drain Valve 5004961N Governor and Check Valve
20. mpressors BW1971 for proper application of the requirement Improper air dryer Bendix AD IS air dryer and reservoir system An extended vehicle application purge model Bendix AD IS EP is available for many higher air usage vehicles such as city buses and construction vehicles If the vehicle is equipped with high air usage accessories such as trailer pump off systems or central tire inflation the air for these accessories must by pass the dryer reservoir system E Air by passes desiccant cartridge assembly valve for proper installation and operation G Purge air exhaust time insufficient due to excessive system leakage 3 Safety valve on air dryer A Defective AD IS air dryer and reservoir A Test to determine if air is passing through check valve Repair popping off or exhausting system delivery check valve or replace Refer to Symptom 1 Remedy B air B Safety valve setting too low lt 150 p s i B Replace safety valve Ai C System pressure too high gt 135p s i C Test with accurate gauge Replace governor if necessary D Excessive pressure pulsations from D Increase volume in discharge line This can be accomplished compressor Typical single cylinder by adding a 90 cubic inch or larger reservoir between the type compressor and the AD IS air dryer and reservoir system 4 Constantexhaustofairatair A Air dryer purge valve leaking A With compressor loaded apply soap solution on purge
21. on amp Leakage Tests listed in this publication WARNING This air dryer is intended to remove moisture and other contaminants normally found in the air brake system Do not inject alcohol anti freeze or other de icing substances into or upstream of the air dryer and reservoir system Alcohol is removed by the dryer but reduces the effectiveness of the device to dry air Use of these or other substances can damage the air dryer and may void the warranty OPERATION amp LEAKAGE TESTS REFER TO THE TROUBLESHOOTING CHART IN THIS MANUAL For additional information see video BW2237 1 Check all lines and fittings leading to and from the air dryer and reservoir system for leakage and integrity Repair any leaks found 2 Build up system pressure to governor cut out and note thatthe Bendix AD IS air dryer purges with an audible escape of air Watch the system pressure and note the pressure fall off for a ten minute period If pressure drop exceeds a for a single vehicle 1 psi minute from either service reservoir or b for tractor trailer 3 psi minute from either service reservoir inspect the vehicle air systems for leak sources and repair them Refer to the Symptoms 1 and 4 in the Troubleshooting Chart 3 Caution Be sure to wear safety glasses in case of a purge blast Check for excessive leakage around the purge valve with the compressor in the charge mode compressing air Apply a soap solution to the purge valve
22. orption Dry air exits the desiccant cartridge through the center of the base assembly then flows to the delivery check valve and through an orifice and into the purge reservoir The delivery check valve opens supplying air to the pressure protection valves A through D simultaneously the safety valve and also to the reservoir port of the attached governor The purge reservoir fills storing air that will be used to regenerate the desiccant during the purge cycle This air is available to supply downstream components during the charge mode When the air pressure reaches approximately 106 psi the four pressure protection valves will open and air will be supplied to the primary reservoir secondary reservoir and accessories If the pressure protection valves are preset to different values the valves will open in order of lowest setting to highest setting when charging a flat system The air dryer and purge reservoir will remain in the charge cycle until the air brake system pressure builds to the governor cut out setting of approximately 130 psi PURGE CYCLE Refer to Figure 3 When air brake system pressure reaches the cut out setting of the governor the governor unloads the compressor activating the purge cycle of the air dryer and reservoir The governor unloads the compressor by allowing air pressure to fill the line leading to the compressor unloader mechanism This suspends the delivery of compressed air to the AD IS
23. reduced braking capacity applications before the parking brakes automatically apply and stay on See Bendix publication BW5057 Air Brake Handbook LOCK TABS SPLASH SHIELD BRACKET SPLASH SHIELD COVER ye FIGURE 7 SPLASH SHIELD BRACKET AND COVER EXPLODED VIEW 1 GENERAL SAFETY GUIDELINES WARNING PLEASE READ AND FOLLOW THESE INSTRUCTIONS TO AVOID PERSONAL INJURY OR DEATH When working on or around a vehicle the following general precautions should be observed at all times Park the vehicle on a level surface apply the parking brakes and always block the wheels Always wear safety glasses Stop the engine and remove ignition key when working under or around the vehicle When working in the engine compartment the engine should be shut off and the ignition key should be removed Where circumstances require that the engine be in operation EXTREME CAUTION should be used to prevent personal injury resulting from contact with moving rotating leaking heated or electrically charged components Do not attempt to install remove disassemble or assemble a component until you have read and thoroughly understand the recommended procedures Use only the proper tools and observe all precautions pertaining to use of those tools If the work is being performed on the vehicle s air brake system or any auxiliary pressurized air systems make certain to drain the air pressure from all reservoirs before beginning A
24. ry ASSEMBLY 1 Lubricate the smaller o ring and check valve body with a heavy duty lithium grease Install this o ring on the check valve body by sliding the o ring over the set of four tapered guide lands The o ring groove holds the o ring in its correct location At the other end of the check valve body the spring is installed over the set of four straight guide lands When the spring has been pushed to the correct location the check valve body is designed to hold the end of the spring in position be sure that the spring is not loose before continuing with this installation Install the assembled check valve body o ring spring in the delivery port so that the o ring rests on its seat and the free end of the spring is visible Grease the adapter and the remaining larger o ring and install it onto the fitting Position the governor gasket then insert the governor mounting bolts through the governor and tighten to 125 in lbs Note Do not replace with a standard compressor governor gasket Re attach line to the governor Before placing vehicle back into service check to see that the system pressure now builds to full operational pressure 1 BENDIX AD IS AIR DRYER AND RESERVOIR SYSTEM TROUBLESHOOTING CHART Dryer is constantly cycling or purging A Excessive system leakage A B Defective delivery check valve C Defective governor D Compressor unloader mechanism D leaking excessively
25. sembly to below 40 Fahrenheit Using an ohmmeter check the resistance between the electrical pins in the air dryer and reservoir system connector half The resistance should be 1 5 to 3 0 ohms for the 12 volt heater assembly and 6 0 to 9 0 ohms for the 24 volt heater assembly Warm the thermostat and heater assembly to approximately 90 Fahrenheit and again check the resistance The resistance should exceed 1000 ohms If the resistance values obtained are within the stated limits the thermostat and heater assembly is operating properly If the resistance values obtained are outside the stated limits replace the heater and thermostat assembly 6 Pressure Protection Valves Observe the pressure gauges of the vehicle as system pressure builds from zero The primary or secondary gauge should rise until it reaches approximately 106 psi 6 psi then level off or a momentary slight fall as the next pressure protection valve opens supplying its reservoir When that pressure gauge passes through approximately 106 THE BENDIX AD IS PRESSURE AIR DRYER GOVERNORS ARE PROTECTION NON ADJUSTABLE VALVE AND FEATURES A BREATHER LOCATIONS VALVE IN THIS PORT FIGURE 5 PRESSURE PROTECTION VALVE LOCATIONS WARNING DO NOT ATTEMPT TO ADJUST OR SERVICE THE PRESSURE PROTECTION VALVES INCORRECT PRESSURE PROTECTION VALVE SETTINGS CAN RESULT IN AUTOMATIC APPLICATION OF VEHICLE SPRING BRAKES WITHOUT PRIOR WARNING psi 6 psi there s
26. small amounts of moisture is normal For Bendix AD IS PuraGuard oil coalescing air dryers only every 3 600 operating hours or 100 000 miles or 12 months Oil removal requirements for air brake quality vary by vehicle manufacturer Because vehicle vocation Jr vfi 208 0 AVIA HEATER amp THERMOSTAT CONNECTOR FIGURE 4 HEATER AND THERMOSTAT CONNECTOR and maintenance can influence when the Bendix AD IS PuraGuard oil coalescing air dryer cartridge requires replacement each fleet should modify their replacement schedule based on experience The change out interval will be extended if the compressor passes a low level of particles The interval will be reduced if excessive carbon particles are delivered to the dryer inlet Higher compressor build up times at idle as well as water or oil in downstream reservoirs indicate an AD IS PuraGuard oil coalescing air dryer desiccant cartridge may need to be replaced Note Asmall amount of oil in the system is normal and should not be considered as a reason to replace the desiccant cartridge Some oil at the dryer exhaust is also normal 2 Visually check for physical damage such as chaffed or broken air and electrical lines and broken or missing parts 3 Checkthe AD IS air dryer and purge reservoir bolts for tightness See Figure 1 Re torque the three air dryer bolts to 360 420 in lbs and the four purge reservoir bolts to 300 360 in Ibs 4 Perform the Operati
27. using a strap wrench andthen test for air leaking through the center of the threaded boss by applying a soap solution to the area Replace the delivery check valve if there is excessive leakage exceeding a 1 bubble in 5 seconds Re grease the seal on the air dryer cartridge before reinstalling Be sure the drain valve on the purge reservoir is not leaking before restoring vehicle to service Check governor at both cut in and cut out position for i proper pressures and ii excessive leakage at fittings and exhaust Remove air strainer or fitting from compressor inlet cavity With compressor unloaded check for unloader piston leakage Slight leakage is permissible 11 BENDIX AD IS AIR DRYER AND RESERVOIR SYSTEM TROUBLESHOOTING CHART 2 Water in vehicle reservoirs A Maximum air dryer inlet temperature is A Check for excessive carbon build up in compressor discharge exceeded due to improper discharge line Replace if required Make certain that discharge line line length length is at least 6 ft Increase discharge line length and or diameter to reduce air dryer inlet temperature Air system charged from outside B If system must have outside air fill provision outside air should air source outside air not passing pass through air dryer through air dryer Excessive air usage Air dryer not C Refer to Bendix Advanced Troubleshooting Guide for Air compatible with vehicle air system Brake Co
28. valve dryer purge valve exhaust excessively exhaust to test for excessive leakage Repair or replace or unable to build system purge valve as necessary pressure Charge mode Refer to Technical Bulletin TCH 008 040 B Purge valve frozen open faulty heater B Refer to paragraph 5 of the Operation and Leakage Tests for and thermostat wiring blown fuse heater and thermostat test C Defective AD IS air dryer delivery C Refer to Symptom 1 Remedy B check valve D Leaking Turbo Cut Off valve D Repair or replace purge valve assembly E Defective governor E Check governor at both cut in and cut out position for i proper pressures and ii excessive leakage at fittings and exhaust F Leaking purge valve control piston F Repair or replace purge valve assembly seals 12 BENDIX AD IS AIR DRYER AND RESERVOIR SYSTEM TROUBLESHOOTING CHART 5 Cannot build system air A Supply pressure to the air dryer is not A Ensure the supply pressure to the air dryer is greater than pressure sufficient 110 psi after the system charges B Kinked or blocked plugged discharge B Check to determine if air passes through discharge line Check for kinks bends excessive carbon deposits or ice blockage C Excessive bends in discharge line C Discharge line should be constantly sloping from compressor water collects and freezes to air dryer with as few bends as possible D Pressure protection valve s
Download Pdf Manuals
Related Search