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Introduction Implement and Steering/Hydraulic System

1. 6 Run the engine at maximum rpm Look at the test gauge and slowly move the bulldozer control lever to the TILT RIGHT position The high reading on the pressure gauge is the pressure setting of the pressure limiter valve The pressure setting of the pressure limiter valve for the bulldozer tilt circuit is 19 800 600 kPa 2875 88 psi 7 If it is necessary to change the pressure setting of the pressure limiter valve stop the engine C212B0P2 3 TEEN ANN cin ESY A z SN ANN o L N i WIE a d es ae ram Fas KS WA TAMU Y 5 4 Bulldozer Tilt Control Valve 3 Plug 4 Plunger adjusting 5 Valve pressure limiter 8 Remove plug 3 from the bulldozer tilt control valve https sisweb cat com sisweb sisweb techdoc techdoc_print_page jsp returnurl sisweb si 2 25 2011 D6H amp D6H LGP TRACTORS POWER SHIFT 7PCO00001 UP MACHINE POW Page 27 of 64 9 Turn adjusting plunger 4 clockwise to increase the pressure setting or counterclockwise to decrease the setting One revolution will change the pressure setting about 5520 kPa 800 psi Do Step 6 again 10 When the pressure setting is correct install plug 3 and tighten it to a torque of 60 5 N m 44 4 lb ft 11 Remove floor plate and test equipment Install floor plate Ripper Lift Circuit 4C4890 Pressure Gauge Kit 1 Put a 0 to 50 000 kPa 0 to 7500 psi pressure gauge on the 6V3081 Hose 2 Remove the floor plate from
2. Page 44 of 64 https sisweb cat com sisweb sisweb techdoc techdoc_print_page jsp returnurl sisweb si 2 25 2011 D6H amp D6H LGP TRACTORS POWER SHIFT 7PCO0001 UP MACHINE POW Page 45 of 64 SPACER CHART PRESSURE CHANGE TO THE VALVES BY REMOVAL OR ADDITION OF ONE SPACER 505 kPa 73 0 psi 293 kPa 42 7 psi 81 kPa 12 0 psi 98 kPa 14 2 psi Load Piston 5 57 kPa 8 3 psi 16 kPa 2 3 26 5M9623 0 90 mm 035 in Clutches Engaged in Tranamission First Speed Forward Second Speed Forward aenda Third Speed Forward Second Speed Reverse 1 and 4 Third Speed Reverse https sisweb cat com sisweb sisweb techdoc techdoc_print_page jsp returnurl sisweb si 2 25 2011 D6H amp D6H LGP TRACTORS POWER SHIFT 7PCO0001 UP MACHINE POW Page 46 of 64 24 4 kez Lan a ke aN mi aoe aa G ea o C07324P6 Priority Valve 1 Valve priority 24 Spacers il ime ec ERO om a i l Zo ai eee ve 4 mei B12110P8 Transmission Hydraulic Control Valve 5 Piston load 3 Valve selector and pressure control 25 Spacers https sisweb cat com sisweb sisweb techdoc techdoc_print_page jsp returnurl sisweb si 2 25 2011 D6H amp D6H LGP TRACTORS POWER SHIFT 7PCO0001 UP MACHINE POW Page 47 of 64 C25299P4 AN 13 AN Converter Outlet Relief Valve 13 Valve converter outlet relief 26 Spacers Linkage
3. If the rpm reading one control handle position is less than 50 rpm and over 50 rpm at the other position then one of the crossover relief valves has a low pressure setting or a makeup valve may be leaking in the steering control valve 7 To determine if the main relief or both crossover relief valves have low pressure settings the main relief valve should be turned in exactly 1 8 revolution maximum Then do Steps 5 and 6 again 019143P3 fm Se MOTOR SIDE OF VALVE Counterbalance Valve Earlier Model Shown 1 Valve crossover relief for right turn 2 Valve crossover relief for left turn 8 If both rpm readings are less than 50 rpm from maximum rpm then the main relief valve has to be replaced or adjusted on a test bench https sisweb cat com sisweb sisweb techdoc techdoc_print_page jsp returnurl sisweb si 2 25 2011 D6H amp D6H LGP TRACTORS POWER SHIFT 7PCO0001 UP MACHINE POW Page 30 of 64 If both rpm readings are over 50 rpm from maximum rpm then replace or inspect the main relief valve and do Steps 5 and 6 again If both readings remain over 50 rpm from maximum rpm then replace or inspect both crossover relief valves If the rpm reading for the MID STEER LEFT position is over 50 rpm from maximum then crossover relief valve 2 or the one toward the left side of the machine should be replaced or adjusted on a test bench If the rpm reading for the MID STEER RIGHT position is over 50 rpm from
4. 1 The temperature of the oil is too hot 2 Pump makes unusual noise the cylinder rods do not move smoothly and there are air bubbles in the oil 3 There is a pause before pressure is reached in all circuits 4 Hydraulic oil transfer into power train oil 5 One or more of the implement control levers or the steering handle moves when not in use when another one of the control levers or steering handle is moved Steering Problem list https sisweb cat com sisweb sisweb techdoc techdoc_print_page jsp returnurl sisweb si 2 25 2011 D6H amp D6H LGP TRACTORS POWER SHIFT 7PCO0001 UP MACHINE POWER Page 4 of 64 1 Machine will not turn in either direction 2 Machine will not turn in one direction 3 Slow turning in either direction 4 Machine turns when steering control handle is released Implement Problem list 1 Implement cycle times are too slow machine not being steered 2 Too much implement drift 3 Implement cycle times are too fast 4 Excessive pause time at ground line when powering blade down Hydraulic System Problem 1 The temperature of the oil is too hot Probable Cause Oil cooler core plugged or no air flow over the core The crossover or main relief settings are too low or the pump cut off pressure is set too high There is a restriction in an oil passage The cooler bypass valve is stuck open The oil level is too low Margin spool in compensator valve set too hig
5. 2 25 2011 D6H amp D6H LGP TRACTORS POWER SHIFT 7PC00001 UP MACHINE POW Page 24 of 64 Pressure limiter valves are installed on each of the implement control valves They control the maximum pressure in each implement circuit Pressure Limiter Valve Settings Bulldozer Bulldozer Ripper Lift Lift Circuit Tilt Circuit Circuit kPa 198004600 198002600 19800 600 2875 88 2875 88 Bulldozer Lift Circuit 2875 88 4C4890 Pressure Gauge Kit 1 Disconnect the rod end hydraulic line from each lift cylinder and install a blocking plate assembly 1 in each line Blocking Plate Installation Typical Example 1 Plate blocking assembly 2 Put a 0 to 50 000 kPa 0 to 7500 psi pressure gauge on the 6V3081 Hose 3 Remove the floor plate from the machine Compensator Valve on Pump 2 Tap pressure https sisweb cat com sisweb sisweb techdoc techdoc_print_page jsp returnurl sisweb si 2 25 2011 D6H amp D6H LGP TRACTORS POWER SHIFT 7PCO00001 UP MACHINE POW Page 25 of 64 4 Install hose and pressure gauge on pressure tap 2 5 Install floor plate 6 Start and run the engine at maximum rpm Look at the test gauge and slowly move the bulldozer control lever to the RAISE position The high reading on the pressure gauge is the pressure setting of the pressure limiter valve The pressure setting of the pressure limiter valve for the bulldozer lift circuit is 19 800 6
6. POWER SHIFT 7PCO0001 UP MACHINE POW Page 37 of 64 C6274P1 22 12 23 SIE WS NJ f 3 Aei N J as a t A Measurement For Spacer Thickness 1 Plate port 2 Barrel cylinder 3 Spacer 4 Pin center 12 Pin centering 19 Support 22 Disc centering 23 Screws lifting 24 Cylinder measuring kit 25 Hole centering 34 Insert barrel 2 spacer 3 and center pin 4 into the centering hole 25 in support 19 Stand cylinder in a vertical position Insert centering pin 12 in port plate 1 and barrel 2 Position centering disc 22 with two lifting screws 23 over the port plate Slide this assembly under the dial indicator The dial indicator must read between 0 10 mm 004 in and 0 20 mm 008 in The motor has four different sizes of spacers to get the correct center pin to port plate distance There is a minimum spacer size Each succeeding size of spacer is 0 10 mm 004 in thicker Depending on the dial indicator reading the correct spacer is selected https sisweb cat com sisweb sisweb techdoc techdoc_print_page jsp returnurl sisweb si 2 25 2011 D6H amp D6H LGP TRACTORS POWER SHIFT 7PCO0001 UP MACHINE POW Page 38 of 64 Thickness Difference From Spacer MM Minimum Spacer MM erieso 36 O min spacer ataza omes o7 o So o o 9T 1646 For example tolerance for dimension B is 0 40 mm 016 in on the dial indicator In
7. Steer Right kPa psi __ kFa pe rpm pm em rpm CA rpm kPafpsl kPajpsi https sisweb cat com sisweb sisweb techdoc techdoc_print_page jsp returnurl sisweb si 2 25 2011 D6H amp D6H LGP TRACTORS POWER SHIFT 7PCO0001 UP MACHINE POWER Page 8 of 64 Implement Operation Checks Make reference to WARNING on the first page of the Implement and Steering Hydraulic System Testing and Adjusting section The operation checks can be used to find leakage in the system They can also be used to find a bad valve pump or motor The speed of rod movement when the cylinders move can be used to check the condition of the cylinders and the pump Raise and lower the blade and ripper several times Operate the tilt control valve until the tilt cylinder is fully extended and retracted several times 1 Watch the cylinders as they are extended and retracted Movement must be smooth and regular 2 Check for noise from the pump 3 Check for the sound of the pressure limiter valves opening The opening pressures of the pressure limiter valves are given in the subject Pressure Tests of the Pressure Limiter Valves Cylinder Speed Tests The oil in the system must be SAE 10 and at a temperature of 65 3 C 150 5 F to get correct results All speed tests are made with the engine at maximum rpm System speeds that are the same as those given in the chart is an indication that the circuit operation is normal
8. adjusted 2 Start and run the engine at maximum rpm Raise all the implements to the FULL Raise position if so equipped 3 Release the parking brake and put the transmission is first speed forward 4 Move to steering control handle the FULL STEER LEFT position 5 Make a full 360 turn 6 Stop the machine after the full turn lower all implements to the ground if equipped and stop the engine 7 Measure distance A as shown Distance A should be 1 8 to 2 3 m 5 9 to 7 5 ft 8 Do Steps 1 through 7 again with steering control handle at FULL STEER RIGHT position 9 Do Steps 1 through 6 again with steering control handle at FULL STEER RIGHT and FULL STEER LEFT positions with the bulldozer control lever held in the FULL RAISE position 10 Measure distance A as shown Distance A should be 4 8 to 6 0 m 16 to 20 ft https sisweb cat com sisweb sisweb techdoc techdoc_print_page jsp returnurl sisweb si 2 25 2011 D6H amp D6H LGP TRACTORS POWER SHIFT 7PCO0001 UP MACHINE POW Page 13 of 64 C181391P1 Full Turn Diameter A Diameter of the turn 11 If distance A is too wide after Steps 1 through 8 check steering linkage pump steering motor control valve and counterbalance valve for correct operation If distance A is too wide after Step 9 and 10 check the priority flow control valve in the steering control valve 12 If a problem has been indicated by this check use the Diagnostic Instrument T
9. have a NEUTRAL detent position https sisweb cat com sisweb sisweb techdoc techdoc_print_page jsp returnurl sisweb si 2 25 2011 D6H amp D6H LGP TRACTORS POWER SHIFT 7PCO0001 UP MACHINE POW Page 41 of 64 Location Of The Pressure Taps A Inlet torque converter B Clutch speed P1 C Clutch direction P2 D Lubrication transmission F Valve priority E Outlet torque converter https sisweb cat com sisweb sisweb techdoc techdoc_print_page jsp returnurl sisweb si 2 25 2011 D6H amp D6H LGP TRACTORS POWER SHIFT 7PCO0001 UP MACHINE POW Page 42 of 64 ane C7325P3 LP Plug Load piston https sisweb cat com sisweb sisweb techdoc techdoc_print_page jsp returnurl sisweb si 2 25 2011 D6H amp D6H LGP TRACTORS POWER SHIFT 7PCO0001 UP MACHINE POW Page 43 of 64 Tranemlasion Presaute Chart l Convener Indet Pressure P3 iA 735 kPa 115 pai ene 63 20 kPa 77 3 psi Add or ramowe Minimum wilh tranemisgion spacers 25 for Selection lever in NEUTRAL toad piston 5 In Load piston pug LP removed selector and pressure control valve See space charl Speed Clutch F1 initial Pressure a i Maximum of 345 kPa 59 psi 2550 105 kPs 370 15 psi None Final Speed Clutch P1 lags than Ihe prassure at with selector fever in arry pressure i MAXIMUM RPM Selector ever FORWARD or REVERS
10. maximum rpm then crossover relief valve 1 or toward the right side of the machine should be replaced or adjusted on a test bench 9 Turn the main relief back out 1 8 revolution if it was not replaced in Step 8 Adjustment of Steering Motor Rotary Grou LI Wee TNA MT MT AE AA SS SSS AL ES yp So FS LY Liked ESSE Sy SANNA Sy _ m E Se f m NRAN SF img KY EES NY COSSD4P1 5 Motor Rotary Group 1 Plate port 2 Barrel cylinder 3 Spacer 4 Pin center 5 Springs compression four 6 Piston seven 7 Shaft 8 Bearings 9 Shims 10 Cover assembly 11 Ring The steering motor rotary group is divided into a mechanical drive group shaft 7 bearings 8 and cover 10 and a hydraulic group barrel 2 port plate 1 spacer 3 compression springs 5 pistons 6 and center pin 4 https sisweb cat com sisweb sisweb techdoc techdoc_print_page jsp returnurl sisweb si 2 25 2011 D6H amp D6H LGP TRACTORS POWER SHIFT 7PCO0001 UP MACHINE POW Page 31 of 64 If parts of the motor are serviced there are two critical dimensions which should be checked in assembling the motor rotary group Shims 9 on the mechanical drive group and one of four spacers 3 on the hydraulic group are used to get these respective dimensions At this point in time the mechanical drive group is a non serviceable group except for the cover assembly 10 NOTICE To prevent damage to the
11. motor it is very important that the cases are filled with hydraulic oil at least to the fill port before operation Use the following chart for adjustment dimensions in servicing the rotary group Gauge Hoch Diet ie aiii kiiun rmn Sandleg 0 1 tp 0 2 mA Steering G713749 107 3 mm 4 224 in 0 1 mm 004 in 186 6 mm 6 374 In 00s to 008 i CLLL AN Ko eh AKK 7z Z N A AR JNK SSeS NO ee Y ANIN NY ae B ESS SAH Sey wE T G ISSS i pote ror O aah antl shed Adjusting Dimensions 12 Pin centering tooling A Distance from ring 11 to shaft 7 B Distance from shaft 7 to centering pin 12 C Play spacer 3 to center pin 4 https sisweb cat com sisweb sisweb techdoc techdoc_print_page jsp returnurl sisweb si 2 25 2011 D6H amp D6H LGP TRACTORS POWER SHIFT 7PCO0001 UP MACHINE POW Page 32 of 64 Adjustment for 40 Displacement Angle Gauge Blocks Use standard gauge set 8T5096 Dial Indicator8T7760 Measuring Kit8T7756 Support 13 Setup for Dial Indicator 13 Blocks gauge 14 Support This shim adjustment is necessary to maintain an exact angle between the center lines of drive shaft 7 and center pin 4 In turn this maintains the proper alignment between the barrel 2 and its pistons 6 https sisweb cat com sisweb sisweb techdoc techdoc_print_page jsp returnurl sisweb si 2 25 2011 D6H amp D6
12. not make any adjustments to the control linkage with the engine running Accidental disengagement of the parking brake while the engine is running could cause sudden machine movement and personal injury Torque for 1 4 in locknuts on cable assembly that hold the rod ends in place 8 3 N m 6 2 lb ft Torque for all 3 8 in locknuts jam nuts that hold the rod ends in place on the rod 12 4 N m 9 3 Ib ft Torque for all 5 8 in locknuts jam nuts on cable assembly 38 7 N m 28 5 lb ft NOTE All rod assembly measurements must be made in a straight line between the centerlines of the rod end mounting holes C19187P2 Transmission And Steering Control Linkage 5 Bolt 6 Locknut 7 Cover A Rod assembly B Rod assembly D Cable assembly E Dimension F Dimension https sisweb cat com sisweb sisweb techdoc techdoc_print_page jsp returnurl sisweb si 2 25 2011 D6H amp D6H LGP TRACTORS POWER SHIFT 7PCO0001 UP MACHINE POW Page 50 of 64 A Assembled length of rod assembly 876 mm 34 5 in B Assembled length of rod assembly 280 1 5 mm 11 02 06 in C Assembled length of rod assembly 823 mm 32 4 in E Dimension 16 2 mm 63 08 in F Dimension 12 2 mm 47 08 in 5 p e l e O 1 j e e ra i tI a re A B Bl 3 ji a A wiped p v4 ji BE l eee EE gt me Craii a ee oo ee te oe C19192P1 Transmission
13. steering linkage should be adjusted 7 Adjustments to the pump output should not be made based on the results of this test If the results are not correct the Margin Pressure Test should be run High Pressure Stall Test 1U5796 Pressure Differential Delta P Gauge Group 1 Remove the floor plate from the machine 2 Install a 1U5755 Hose Assembly on pressure tap 1 and pressure tap 2 Connect the other ends of the hoses to 1U5793 Delta P Delta P Gauge Connect the hose from pressure tap 1 to the tee side of the Delta P gauge Connect the hose from pressure tap 2 to the elbow side of the Delta P gauge Compensator Valve On Pump 2 Tap pressure 3 Install the 8T0861 Gauge on the tee side of the Delta P gauge 4 Install the floor plate 5 Start the engine and run at maximum rpm Release the parking brake and activate the service brakes 6 Move the steering control handle to a position in between HOLD and the MID STEER LEFT position 7 The pressure reading on the 8T0861 Gauge should be 38 500 550 kPa 5575 80 psi This is the pumps pressure output in the high pressure stall condition The pressure reading on the Delta P gauge should be less than 345 kPa 50 psi at a maximum oil temperature of 66 C 150 F 8 If the high pressure reading is not correct then the pressure cut off spool should be adjusted See Compensator Valve Adjustments If the pressure reading on the Delta P gauge is high and the high pre
14. the machine Compensator Valve on Pump 2 Tap pressure 3 Install hose and pressure gauge on pressure tap 2 4 Install floor plate 5 Start and run the engine Lift the ripper as high as it can lift 6 Run the engine at maximum rpm Look at the test gauge and slowly move the ripper control lever to the RAISE position The high reading on the pressure gauge is the pressure of the pressure limiter valve The pressure setting of the pressure limiter valve for the ripper lift circuit is 19 800 600 kPa 2875 88 psi 7 If it is necessary to change the pressure setting of the pressure limiter valve stop the engine https sisweb cat com sisweb sisweb techdoc techdoc_print_page jsp returnurl sisweb si 2 25 2011 D6H amp D6H LGP TRACTORS POWER SHIFT 7PCO00001 UP MACHINE POW Page 28 of 64 C21280P2 3 ie a Me at Pe LLEN aag Te 3 4 Ripper Lift Control Valve 3 Plug 4 Plunger adjusting 5 Valve pressure limiter 8 Remove plug 3 from the ripper lift control valve 9 Turn adjusting plunger 4 clockwise to increase the pressure setting or counterclockwise to decrease the setting One revolution will change the pressure setting about 5520 kPa 800 psi Do Step 6 again 10 When the pressure setting is correct install plug 3 and tighten it to a torque of 60 5 N m 44 4 b ft 11 Remove floor plate and test equipment Install floor plate Main Relief and Crosso
15. this case remove the spacer with the minimum thickness and replace with a spacer that increases the indicator reading by 0 20 mm 008 in to give a B dimension of 136 3 mm 5 366 in Once the correct spacer has been selected the center pin 4 can be removed The four compression springs 5 can then be inserted using a piece of wire 20 as a guide 20 Z SS AAN Installation Of Compression Springs 5 Springs compression 20 Wire Power Shift Transmission Testing And Adjusting https sisweb cat com sisweb sisweb techdoc techdoc_print_page jsp returnurl sisweb si 2 25 2011 D6H amp D6H LGP TRACTORS POWER SHIFT 7PCO0001 UP MACHINE POW Page 39 of 64 When some tests and adjustments are made to the transmission the parking brake must be OFF To prevent movement of the machine and personal injury do the procedure that follows 1 Lower the bulldozer and ripper to the ground 2 Put blocks in front of and behind the tracks 3 Let only approved personnel on the machine and keep other personnel off the machine and in clear view of the operator 4 When testing must be done in a closed area and whenever possible engage the service brakes if the parking brake can not be used NOTE All tests and adjustments must be made with the oil in the power train hydraulic system at normal temperature for operation Make sure that the linkage adjustments are correct before any tests are made Many of the pre
16. 00 kPa 2875 88 psi 7 If it is necessary to change the pressure setting of the pressure limiter valve stop the engine C21281P2 3 W EEN Erza A d Femme RN H BSR OAR AR Spa NY oMsMems Mee s o A er a g r ae r A a ol Fa 4 i SJ ESS Ya NIT ge YS 5 4 Bulldozer Lift Control Valve 3 Plug 4 Plunger adjusting 5 Valve pressure limiter 8 Remove plug 3 from the bulldozer lift control valve 9 Turn adjusting plunger 4 clockwise to increase the pressure setting or counterclockwise to decrease the setting One revolution will change pressure setting about 5520 kPa 800 psi Do Step 6 again 10 When the pressure setting is correct install plug 3 and tighten it to a torque of 60 5 N m 44 4 lb ft 11 Remove floor plate and test equipment Install floor plate Bulldozer Tilt Circuit 4C4890 Pressure Gauge Kit 1 Put a 0 to 28 000 kPa 0 to 4000 psi pressure gauge on the 6V3081 Hose 2 Remove the floor from the machine https sisweb cat com sisweb sisweb techdoc techdoc_print_page jsp returnurl sisweb si 2 25 2011 D6H amp D6H LGP TRACTORS POWER SHIFT 7PCO0001 UP MACHINE POW Page 26 of 64 DEY Compensator Valve on Pump 2 Tap pressure 3 Install hose and pressure gauge on pressure tap 2 4 Install floor plate 5 Start and run engine Lift the bulldozer blade approximately 300 mm 12 in off the ground Tilt the blade to the right as far as it can tilt
17. 23 0 rpm 7 Now add the left sprocket speed and right sprocket speed The sum should be 3 5 rpm This step checks the mechanical drag balance between left and right sprockets Example Left sprocket speed 12 5 rpm Add Right sprocket speed 10 5 rpm Add left and right sprocket speed 2 0 rpm 8 Do Steps 5 6 and 7 again but move the steering control lever to FULL STEER LEFT position Sprocket speed difference for FULL STEER LEFT position should be 22 5 1 1 rpm 9 If sprocket speeds are not within the tolerances check component operation pump steering motor control valve and counterbalance valve If Step 6 is low check the engine speed leaks in signal system and priority flow control valve in steering control valve If Step 6 is high check the priority flow control valve and compensator valve adjustments If Step 7 is out of tolerance excessive mechanical drag may be present in differential steer unit and final drives 10 If a problem has been indicated by this check use Diagnostic Instruments Test to get a more accurate indication to where the specific problem exists 11 When checks tests and adjustments if necessary are complete stop engine remove all test equipment and connect the track Diagnostic Instrument Tests Make reference to WARNING on the first page of the Implement and Steering Hydraulic System Testing and Adjusting section Also always replace floor plate when performing tests and whene
18. 3 Check continuity through switch 12 If there is no continuity adjust the position of switch 12 with the following steps 4 To adjust the position of switch 12 remove three screws 22 and cover assembly 25 5 Loosen switch screws 26 and reposition switch 12 Recheck continuity as in Step 3 and reposition switch if necessary Backup Alarm Adjustment Procedure 1 Engage the parking brake Release the brake and rotate handle 2 15 toward Reverse counterclockwise Check continuity through switch 14 If there is no continuity within 1 of the 15 angle adjust the position of switch 14 2 To adjust the position of switch 14 remove three screws 22 and remove cover assembly 25 3 Loosen switch screws 27 and reposition switch 14 Recheck continuity as in Step 1 and readjust switch if necessary
19. 5 mm 1 8 in from the support Bolt 5 is the upper stop for the brake pedal 4 Hold brake pedal against upper stop and push valve plunger all the way into valve 1 Then adjust rod end on rod assembly C so that the pin that connects rod end to valve plunger has a free fit 5 Push brake pedal down until valve plunger stops https sisweb cat com sisweb sisweb techdoc techdoc_print_page jsp returnurl sisweb si 2 25 2011 D6H amp D6H LGP TRACTORS POWER SHIFT 7PCO0001 UP MACHINE POW Page 54 of 64 6 Adjust bolt 4 until head contacts brake pedal 7 Release brake pedal and turn bolt 4 an additional 1 2 turn out Tighten locknut Later Models C40076P 1 1 Bolt 2 Adjustment Bolt 3 Locknut 4 Spring 5 Adjustment Bolt 6 Locknut 7 Locknut 8 Rod end 9 Pin 10 Service brake pedal 1 Torque for bolt 120 20 N m 90 15 lb ft 7 Torque for locknut 45 7 N m 33 5 1b ft Procedure To Adjust Service Brake Pedal Linkage 1 Adjust spring 4 stretch to 3 1 mm 11 04 in with adjustment bolt 2 and secure in place with locknut 3 2 With service brake pedal 10 against the upper stop and valve stem depressed adjust rod end 8 to allow free fit of pin 9 in rod end and valve stem 3 With service brake pedal 10 depressed and valve stem extended adjust bolt 5 until it is in contact with service brake pedal 4 Release service brake pedal and adjust bol
20. Adjustments Transmission Speed Control Earlier Models Transmission control linkage adjustment should be made only with engine OFF Accidental transmission engagement and sudden machine movement could cause personal injury https sisweb cat com sisweb sisweb techdoc techdoc_print_page jsp returnurl sisweb si 2 25 2011 D6H amp D6H LGP TRACTORS POWER SHIFT 7PCO0001 UP MACHINE POW Page 48 of 64 C10000P1 Transmission Control Linkage 1 Lever control 2 Cable assembly 3 Locknut 4 Rod assembly 5 Locknut 6 Bolt 7 Cover 8 Locknut Torque for 1 4 in locknuts 8 on cable assembly 2 that hold the rod ends in place 8 3 N m 6 2 lb ft Torque for 3 8 in locknuts 3 on rod assembly 4 12 4 N m 9 3 lb ft Torque for all 5 8 in jam nuts 38 7 N m 28 5 lb ft Assembled length of rod assembly 4 202 0 1 5 mm 7 95 06 in Procedure For Adjustment 1 Remove bolts 6 that hold cover 7 to the housing 2 Loosen locknut 5 for cable 2 Turn cover 7 to move cable 2 that adjusts control lever 1 3 Adjust control lever 1 so that it does not make contact with the guide in any speed or in neutral Steering And Transmission Directional Control Earlier Models https sisweb cat com sisweb sisweb techdoc techdoc_print_page jsp returnurl sisweb si 2 25 2011 D6H amp D6H LGP TRACTORS POWER SHIFT 7PCO0001 UP MACHINE POW Page 49 of 64 Do
21. And Steering Control Linkage 1 Plate 2 Shaft assembly 3 Plate 4 Lever 8 Lever 9 Lever A Rod assembly B Rod assembly C Rod assembly D Cable assembly https sisweb cat com sisweb sisweb techdoc techdoc_print_page jsp returnurl sisweb si 2 25 2011 D6H amp D6H LGP TRACTORS POWER SHIFT 7PCO0001 UP MACHINE POW Page 51 of 64 C12549P4 VIEW A A Steering Control Lever 10 Handle 11 Collar 12 Plate shaft assembly 13 Lever 14 Shaft assembly C Rod assembly G Dimension G Dimension 40 0 2 0 mm 1 57 08 in Procedure For Adjustment Of Steering Control Linkage 1 Install assembled and adjusted rod assemblies A and B 2 Install lever 13 on shaft assembly 2 so that lever 13 forms a 75 4 angle with plate 3 on shaft assembly 2 3 Install shaft assembly 2 on the machine and make sure the top of shaft assembly 2 and lever 13 are above plate 1 the dimension shown in view A A 4 Install lever 4 on shaft assembly 2 so that lever 4 forms a 193 4 angle with plate 3 5 Move parking brake lever to the ON position and then adjust rod assembly A so there is a free fit between lever 8 and the bolt to hold rod assembly A to lever 8 6 Move parking brake lever to the OFF position Move steering control handle to the FULL RIGHT TURN position and FULL LEFT TURN position Make sure the steering control valve lever moves its full tra
22. E controlled by the in any FORWARD o REVERSE speed Load slon plug LP Initial Prassure spaad Load piston plug LF inslaled Setting installed 980 55 kPa 55 8 psi less S80 66 kPa 55 6 pel less NONE Direction Dwreclion Clutch ic than the speed cluich pressure Ihan ihe speed clutch pressure Clutch pressure is P2 at lap 6 Selector lever in any al tep B Selecior ever in any contraliad by the FORWARD or REVERSE FORWARD or REVERSE Spring rate For th Speed Load piston plug LP speed Load piston plug LF pressure installed installed diferential valve spring Transmission Lutricatian Oil 3 5 kPa S psl Minimum 2760 50 kPa 37 5 7 5 psi NOME D Conwarter iE Outlet Pressure 410 amp 70 kPa 80 t 10 pst Add or remova with Drakes engaged selector Spacers 20 In ever in THIRD SPEED converter autiel FORWARD anc converter in a rellat valve 13 stall condition See Spacer Char Add or remove tc 2900 140 kPa 420 amp 20 psi BPAST 24 in pridrily valve 1 See Spacer Char 2925 140 kPa 410 20 pel wilh foot brake off Less than 7 NONE KPa 1 D5 With foot brake ON 80 29 kPa 12 3 pail NONE 3375 176 kPa 495 25 pal NONE 550 kPa 80 pail NONE Priority Valve Brake G H tight or left Pump Drive Lubr kation PRESSURE DIFFERENTIAL VALVE TEST Pressure With the engine not running move Ihe direction selection lever lo any position excapl NEUTRAL
23. H LGP TRACTORS POWER SHIFT 7PCO0001 UP MACHINE POW Page 33 of 64 15 C06271P 1 Measurement for Shim Thickness 14 Support 15 Cover 16 Ring location 17 Shims 18 Boss Place support 14 on a surface plate Position the gauge blocks 13 on the support to get dimension A Set the indicator in position over the gauge blocks and zero the dial Position the mechanical drive group on support 14 so that boss 18 is located over the hole in the support Place cover 15 without the seal and O ring on the drive group Do not install the ring at location 16 Slide drive group and support under the dial indicator Add shims 17 to get a reading on the indicator between 0 and 0 10 mm 004 in Mechanical Drive Group 15 Cover 17 Shims https sisweb cat com sisweb sisweb techdoc techdoc_print_page jsp returnurl sisweb si 2 25 2011 D6H amp D6H LGP TRACTORS POWER SHIFT 7PCO0001 UP MACHINE POW Page 34 of 64 Adjustment of Lift Off Limitation Cylinder Barrel to Port Plate Maximum Separation Tools Needed me OOOO CT Tegese OOO o swen T776 Centering Disc 877759 with two screws Spacer 3 to pin 4 clearance in combination with the compression springs 5 maintain the correct barrel 2 to port plate 1 maximum separation This maximum separation limits leakage during start up and downhill operation Measuring Kit This adjustment procedure determi
24. Page 1 of 64 Testing And Adjusting Introduction Reference This supplement contains the Specifications Systems Operation and Testing And Adjusting for the components and systems that are different than those of the D6H Steering Clutch and Brake Machines For complete Specifications with illustrations Systems Operation and Testing and Adjusting Procedures for components and systems not shown in this supplement make reference to D6H Service Manual Form No SENR3235 Implement and Steering Hydraulic System Testing and Adjusting Sudden movement of the machine or release of oil under pressure can cause injury to persons on or near the machine To prevent possible injury do the procedure that follows before testing and adjusting the implement and steering hydraulic system 1 Move the machine to a smooth horizontal location Move away from working machines and personnel and lower implements to the ground 2 Permit only one operator on the machine Keep all other personnel either away from the machine or in view of the operator D6H amp D6H LGP TRACTORS POWER SHIFT 7PCO0001 UP MACHINE POWER Page 2 of 64 3 Engage the parking brake With the parking brake engaged the steering tiller handle can not be moved If the parking brake is OFF and the engine is running the machine will turn when the steering tiller handle is moved Engage the service brakes to prevent machine movement 4 Stop the engine 5 Move the implem
25. Start the Differential angine and run al HISH IDLE The direction clutoh pressure P2 must be O kPa 0 psi the speed cfuteh Valve pressure P1 must ba 2550 105 kPa 370 16 psi Move the direction selection laver io NEUTRAL and t8 then to THIRD SPEED FORWARD or REVERSE The direction clutch pressurs P2 must be 80 55 kPa 55 B psi lass ihan iha speed clutch pressura NOTE It the vahicle is equipped with a n wtral start swilch the transmission control laver must be in NEUTRAL bela ihe startar r engaged te slart Ihe angine Transmission Oil Pump Bench Test Specifications Type Gear Number of sections Three https sisweb cat com sisweb sisweb techdoc techdoc_print_page jsp returnurl sisweb si 2 25 2011 D6H amp D6H LGP TRACTORS POWER SHIFT 7PCO00001 UP MACHINE POW Rotation seen from drive end Counterclockwise Output of transmission charging section use SAE 10W oil at 49 C 120 F minimum 106 liter min 28 U S gpm At a pump speed of 1800 rpm At a pressure of 3100 kPa 450 psi Output of brake lubrication section use SAE 10W oil at 49 C 120 F minimum 53 liter min 14 U S gpm At a pump speed of 1800 rpm At a pressure of 140 kPa 20 psi Output of transmission and torque converter scavenge section use SAE 10W oil at 49 C 120 F minimum 98 liter min 26 U S gpm At a pump speed of 900 rpm At a pressure of 140 kPa 20 psi
26. The pressure limiter valves must be tested to be sure that the opening pressure of each is correct See chart for settings If all the cylinder speeds are slow check the steering circuit to see if the problem is in the pump or steering motor Bulldozer Speed In Blade Bulldozer Tilt Cylinder Speed Test Seconds amp U FULL TILT RIGHT to FULL TILT 2 4 LEFT Max A 1 8 Max https sisweb cat com sisweb sisweb techdoc techdoc_print_page jsp returnurl sisweb si 2 25 2011 D6H amp D6H LGP TRACTORS POWER SHIFT 7PCO0001 UP MACHINE POWER Page 9 of 64 Bulldozer Speed In Blade Bulldozer Lift Cylinder Speed Test Seconds S U amp A_ FULL DOWN to FULL UP Max FULL UP to FULL DOWN quick drop Ripper Cylinders Speed Test FULL DOWN to FULL UP w o shank 5 6 Max Speed In Seconds 2 8 Max If the cylinder speeds are not correct 1 If only one of the cylinder speeds is slow check that circuit for cylinder drift 2 If all the cylinder speeds are slow check the steering circuit to see if the pump signal is plugged or if the pump has a problem Drift Tests for Bulldozer Lift Cylinders Bulldozer Lift Cylinder Drift Oil 28 to 48 C 49 to 68 C 69 to 88 C Temperature 83 to 118 F 120 to 155 F 156 to 190 F 2 5 7 1 7 minutes minutes minutes Raise the front of the machine off the ground by lowering a level blade Put the
27. Torque for all 1 4 in locknuts on cable assembly that hold the rod ends in place 8 2 N m 6 1 5 lb ft https sisweb cat com sisweb sisweb techdoc techdoc_print_page jsp returnurl sisweb si 2 25 2011 D6H amp D6H LGP TRACTORS POWER SHIFT 7PCO0001 UP MACHINE POW Page 63 of 64 Torque for the 3 8 in locknut jam nut that holds the swivel rod end on the center rod 30 7 N m 22 5 b ft Torque for all 5 8 in locknuts jam nuts on cable assembly 38 7 N m 28 5 lb ft 4 Torque for four screws 8 2 N m 6 1 5 lb ft 7 Torque for nut 8 2 N m 6 1 5 lb ft 10 Torque for screw 17 4 N m 13 3 1b ft 11 Dimension two places 15 2 mm 59 08 in 13 Dimension 16 2 mm 63 08 in 15 5N6096 Spring Length under test force 25 50 mm 1 004 in Test force 19 57 N 4 40 lb Free length after test 48 77 mm 1 920 in Outside diameter 13 82 mm 544 in 16 6Y2846 Spring Length under test force 74 64 mm 2 939 in Test force 626 N 140 8 1b Free length after test 79 92 mm 3 146 in Outside diameter 20 mm 79 in 17 Dimension two places 16 2 mm 63 08 in 18 Torque for three screws 1 7 0 25 N m 15 2 2 1b in 19 Torque for two bolts that hold collar 0 8 0 1 N m 7 1 Ib in 20 Depth to install bearing 4 5 1 0 mm 18 04 in 22 Torque for three screws 8 2 N m 6 1 5 l
28. age not adjusted correctly 2 Pump will not develop steering pressure A Signal line is damaged B Shuttle valve will not move stuck or has failed seals C Flow control sleeve behind flow control spring has failed seals D Plug in end of steering valve spool is leaking E Signal line orifice is plugged F Main relief valve is stuck open has failed seals or relief setting is too low G Margin spool pressure cutoff spool or piston in pressure cutoff spool is stuck H Crossover relief valves set too low or have failed seals I Pump has damage 3 Steering motor has damage 4 Mechanical damage in steering differential Problem 2 Machine will not turn in one direction Probable Cause 1 Steering control linkage not adjusted correctly 2 Crossover relief valves are damaged sticking open have failed seals or are set too low 3 A steering control valve makeup valve is stuck open or has failed seals 4 Counterbalance valve stem sticking 5 Motor port plate broken or scored 6 Mechanical damage in steering differential Problem 3 Slow turning in either direction Probable Cause 1 Steering control linkage not adjusted correctly 2 Margin spool in compensator valve is set too low or stuck 3 Crossover relief valves are damaged sticking open have failed seals or are set too low 4 Main relief valve is stuck open has failed seals or relief setting is too low 5 A steering control valve makeup valve is st
29. b ft 24 Depth to install bearing 1 5 1 0 mm 06 04 in 26 27 Torque for four bolts that tighten switch 0 5 0 05 N m 4 4 5 Ib in https sisweb cat com sisweb sisweb techdoc techdoc_print_page jsp returnurl sisweb si 2 25 2011 D6H amp D6H LGP TRACTORS POWER SHIFT 7PCO0001 UP MACHINE POW Page 64 of 64 Speed Control Adjustment Procedure 1 Rotate collar 23 until the number 2 is 30 1 counterclockwise from vertical as viewed from the end of handle 2 Tighten the bolt that holds collar 23 to a torque of 1 7 0 20 N m 15 1 8 Ib in 2 With plate 5 removed rotate lever 9 until it is parallel with the top of housing 8 Install handle assembly 3 with the white mark in line with the number 2 on collar 23 Forward Reverse Adjustment Procedure 1 Rotate ring 21 so screw 22 is in the center of the slot Tighten two screws 19 to a torque of 0 8 0 1 N m 7 1 lb in 2 With parking brake lever 1 in the engaged position rotate handle 2 until the white mark on the handle lines up with N NEUTRAL on ring 21 Tighten three screws 18 to a torque of 1 7 0 25 N m 15 2 2 Ib in Neutral Start Switch Adjustment Procedure 1 With parking brake lever 1 in the engaged position loosen screw 10 and remove parking brake lever 1 2 Install parking brake lever 1 on splined shaft 6 so that the hole in lever 1 is in line with the hole in plate 5
30. control lever in HOLD position Shut off the engine and watch the lift cylinder rods for movement Must not move Test No 1 Test No 2 Raise the front of the machine off the ground by lowering a level blade Shut off the engine Hold the lift control lever in LOWER position Watch the lift cylinder rods for movement Test No 3 https sisweb cat com sisweb sisweb techdoc techdoc_print_page jsp returnurl sisweb si 2 25 2011 D6H amp D6H LGP TRACTORS POWER SHIFT 7PCO0001 UP MACHINE POW Page 10 of 64 Raise the blade off the ground Put the control lever in HOLD position Shut off the engine and watch the lift cylinder rods for movement Test No 4 Raise the blade off the ground Shut off the engine Hold the lift control lever in RAISE position Watch the lift cylinder rods for movement Test Results Most Probable Causes Drifting occurs in Lift circuit make up valve Tests No 1 and No 2 head ends leaking Drifting occurs in Leakage between lift Tests No 1 and No 3 valve spool and body Drifting occurs in Leakage between pistons Tests No 1 No 2 No 3 and cylinders Bad piston and No 4 valves in cylinders Quick drop valve leaks Drifting occurs in Lift circuit load check Tests No 2 and No 4 valve or flow control valve is leaking NOTE Remember that an O ring seal failure in the circuit will have the same effect as a major component failure Drift Tests for Bulldozer Tilt C
31. e Fuel Specifications Zero T for most current specification for engine 9 With engine still at maximum rpm move the bulldozer control lever to a position in between HOLD and FULL RAISE positions Record the reading on Delta P gauge while the bulldozer blade is still moving up The reading on the Delta P gauge is margin pressure or the difference between pump discharge pressure and the signal pressure from the control valve The margin pressure should be 2100 275 kPa 305 40 psi If the margin pressure is not correct then see Compensator Valve Adjustments Margin Pressure Adjustment for the correct procedure to make an adjustment If the margin pressure is adjusted the differential pressure setting should be held to 2100 70 kPa 305 10 psi 10 Lower bulldozer blade to the ground and leave all implement control levers in the HOLD position 11 Release the parking brake and fully activate the service brakes Make sure the transmission is in neutral both speed and direction NOTE On later model machines the speed selector does not have a NEUTRAL position https sisweb cat com sisweb sisweb techdoc techdoc_print_page jsp returnurl sisweb si 2 25 2011 D6H amp D6H LGP TRACTORS POWER SHIFT 7PCO0001 UP MACHINE POW Page 16 of 64 12 With engine at maximum rpm move steering control handle to the MID STEER RIGHT position This puts the hydraulic system in a steer stall condition NOTE The machine must not move if it do
32. e ripper Put the ripper control lever in HOLD position Shut off the engine and watch the ripper lift cylinder rod for movement Test No 2 Raise the ripper off the ground Put the control lever in HOLD position Shut off the engine and watch the ripper lift cylinder rod for movement Most Probable Causes Drifting occurs in Tests Leakage between piston No 1 and No 2 and cylinder Leakage between ripper lift circuit Drifting occurs in Test No 1 valve spool and body NOTE Remember that an O ring seal failure in the circuit will Lift circuit makeup valve head end leaking have the same effect as a major component failure https sisweb cat com sisweb sisweb techdoc techdoc_print_page jsp returnurl sisweb si 2 25 2011 D6H amp D6H LGP TRACTORS POWER SHIFT 7PCO0001 UP MACHINE POW Page 12 of 64 Steering Operation Checks Make reference to WARNING on the first page of the Implement and Steering Hydraulic System Testing and Adjusting section Steering operation checks are indications that the steering circuit operation is normal The sprocket speed and steering turn checks are the checks that will give an indication of steering circuit problems Steering Turn Diameter Check 1 Move the machine to a flat and dry open area Make sure the underfoot conditions are such that a limited amount of track slip will be present when turning the machine Make sure the steering linkage is correctly
33. ent control levers to all positions to release the pressure in the implement and steering hydraulic system 6 Carefully loosen the filler cap on the hydraulic tank to release the pressure in the tank 7 Make sure all hydraulic pressure is released before any fitting hose or component is loosened tightened removed or adjusted 8 Tighten the filler cap on the hydraulic tank 9 The pressure in the system has now been released and lines or components can be removed NOTE During a diagnosis of the implement and steering hydraulic system remember that correct oil flow and pressure are necessary for correct operation Oil pressure is caused by resistance to the flow of oil Procedure When defining an implement and steering hydraulic system problem the following procedure should be followed First do Visual Checks If when complete the problem has not been identified do operation checks If the problem is still not fully understood do Instrument Tests This procedure will help identify implement and steering hydraulic system problems As soon as the problem is defined go to Troubleshooting The Troubleshooting section will list the probable causes of a known problem Since there may be more than one cause for a problem the Troubleshooting section may suggest specific inspections or instrument tests be done These inspections and tests will help identify which of the causes is most probable Use this as a reference for the locati
34. es the brake system must be checked 13 With the machine in a steer stall condition record the following readings A Pump discharge pressure read gauge on tee side of Delta P gauge B Engine rpm C Pressure on Delta P gauge 14 Readings from Step 13 should be as follows A 38 000 550 kPa 5510 80 psi B 50 rpm or less below the reading recorded in Step 8 C 50 psi maximum with a maximum oil temperature of 66 C 150 F If all readings are within specification the steering hydraulic circuit should be alright but there still could be a problem in the individual implement circuits If a steering problem still exists it could be a mechanical problem in the steering differential unit or the final drives A continued implement circuit problem could be a pressure limiter adjusted incorrectly or cylinder wear If reading A is too high or too low 1 The pressure cut off needs to be adjusted see Compensator Valve Adjustments Pressure Cut Off Adjustment in this section NOTE If the pressure cut off can not be adjusted down the pump or compensator valve has failed If reading A is correct or too low reading B is correct and reading C is too high this indicates a leak s in the signal network between the steering control valve and the compensator valve The causes for the leak s could be the following 1 Seals on shuttle valve in steering control valve 2 Dirt or foreign material in shuttle valve in steering cont
35. est to get a more accurate indication to where the specific problem exists Sprocket Speed Checks NOTE This check should be used primarily in a shop area after a machine has been repaired or rebuilt 1 Move the machine to a flat and open area Lower the implements to the ground and stop engine 2 Separate the tracks and remove from the final drive sprockets See Power Train Disassembly and Assembly Form No SENR4176 3 Before checks are made make sure the steering linkage is correctly adjusted Also put a mark on both final drives so the number of revolutions they make can be counted 4 Start the engine and run at maximum rpm 5 Release parking brake and move the steering control lever to the FULL STEER RIGHT position with transmission in Neutral 6 With a stopwatch count the number of revolutions the left and right side sprockets make in a minute Subtract the right sprocket speed from the left sprocket speed Forward rotation is positive and reverse rotation is negative The speed difference between left sprocket and right sprocket should be 22 5 1 1 rpm This step checks the pumps flow through the system https sisweb cat com sisweb sisweb techdoc techdoc_print_page jsp returnurl sisweb si 2 25 2011 D6H amp D6H LGP TRACTORS POWER SHIFT 7PCO0001 UP MACHINE POW Page 14 of 64 Example Left sprocket speed 12 5 rpm Minus Right sprocket speed 10 5 rpm Subtract right from left sprocket speed
36. h Charging valve is stuck closed Control stem partially shifted ANAM BB WN Problem 2 Pump makes unusual noise the cylinder rods do not move smoothly and there are air bubbles in the oil Probable Cause 1 Oil aeration from a loose connection or restriction of the oil line on the inlet side of pump 2 The oil level is too low 3 The cylinders and lines are not properly purged of air 4 Porous welds or broken baffles in hydraulic tank Problem 3 There is a pause before pressure is reached in all circuits Probable Cause 1 Air in signal network 2 Margin spool in compensator valve is set too low 3 Orifice to flow control valve restricted Problem 4 Hydraulic oil transfer into power train oil Probable Cause 1 Excessive pump seal leak into flywheel housing 2 Excessive motor seal leak into bevel gear case https sisweb cat com sisweb sisweb techdoc techdoc_print_page jsp returnurl sisweb si 2 25 2011 D6H amp D6H LGP TRACTORS POWER SHIFT 7PCO0001 UP MACHINE POWER Page 5 of 64 Problem 5 One or more of the implement control levers or the steering handle moves when not in use when another one of the control levers or steering handle is moved Probable Cause 1 Linkage interference 2 Plug in the end of a control valve spool is missing 3 End cover drain holes do not intersect Steering Problem 1 Machine will not turn in either direction Probable Cause 1 Steering control link
37. ine running Accidental disengagement of the parking brake while the engine is running could cause sudden machine movement and personal injury C21276F1 Brake Pedal Linkage 1 Valve service brake control 2 Bolt 3 Pedal brake 4 Bolt adjusting B Rod assembly C Rod assembly https sisweb cat com sisweb sisweb techdoc techdoc_print_page jsp returnurl sisweb si 2 25 2011 D6H amp D6H LGP TRACTORS POWER SHIFT 7PCO0001 UP MACHINE POW Page 53 of 64 Torque for all 1 2 in locknuts jam nuts that hold the rod ends in place on the rod 45 7 N m 33 5 lb ft NOTE All rod assembly measurements must be made in a straight line between the centerlines of the rod end mounting holes B Assembled length of rod assembly 975 0 1 5 mm 38 38 06 in C Assembled length of rod assembly 386 0 2 0 mm 15 20 08 in 2 Torque for bolt 135 15 N m 100 11 1b ft VIEW A A 01012P5 Brake Pedal Linkage 5 Bolt adjusting upper stop X Distance Procedure To Adjust Service Brake Pedal Linkage 1 Install adjusted rod assemblies B and C 2 Install pedal 3 so that the slot of the pedal is one spline tooth down counterclockwise from the timing mark on the shaft NOTE To bring the pedal closer to the operator the centerline of the slot of pedal 3 must be in alignment with the timing mark on the shaft 3 Adjust the head of bolt 5 to dimension X 4
38. ite direction Tighten nut 6 to a torque of 30 7 N m 22 5 lb ft To Check Parking Brake Adjustment 1 Check brake pressure with the parking brake lever in the ON and OFF position See Power Shift Transmission Testing And Adjusting in this module for location of pressure tap https sisweb cat com sisweb sisweb techdoc techdoc_print_page jsp returnurl sisweb si 2 25 2011 D6H amp D6H LGP TRACTORS POWER SHIFT 7PCO0001 UP MACHINE POW Page 60 of 64 2 The brake pressure with the parking brake lever in the ON position should be 0 kPa 0 psi If not make rod assembly 8 longer 3 The brake pressure with the parking brake lever in the OFF position should be 2825 140 kPa 410 20 psi If not make rod assembly 8 shorter 4 Do Step 1 again if rod assembly adjustments were needed https sisweb cat com sisweb sisweb techdoc techdoc_print_page jsp returnurl sisweb si 2 25 2011 D6H amp D6H LGP TRACTORS POWER SHIFT 7PCO0001 UP MACHINE POW Page 61 of 64 Steering And Transmission Hand Control https sisweb cat com sisweb sisweb techdoc techdoc_print_page jsp returnurl sisweb si 2 25 2011 D6H amp D6H LGP TRACTORS POWER SHIFT 7PCO0001 UP MACHINE POW Page 62 of 64 Do not make any adjustment to the control linkage with the engine running Accidental disengagement of the parking brake while the engine is running could cause sudden machine movement and personal injury
39. knut on cable 12 and turn cover 17 as necessary Steering Control Assembly Procedure 1 Install rod assemblies 2 and 3 after they have been adjusted to the correct dimensions 2 Assemble lever 24 to the shaft assembly Align the timing mark on the tube assembly with the lever arm and bolt head side of the lever saw cut If unable to align the timing mark with the bolt head side of the lever saw cut rotate the lever counterclockwise as viewed from the bottom one spline and install lever Lever should be installed 5 1 mm 20 04 in above the bottom of the splined tube assembly Tighten the lever clamping bolt 3 Engage the parking brake 4 Adjust the length of rod 2 to allow free fit of bolt 25 into bellcrank 26 Parking Brake Adjustment Procedure 1 Engage the parking brake 2 Assemble rod end 9 and nut 6 to threaded rod 8 Do not tighten nut 6 3 Assemble rod eye 10 into the parking brake valve spool until bottomed Tighten nut 11 against the washer and the valve spool to a torque of 30 7 N m 22 5 lb ft 4 Push the parking brake valve spool to the down position 5 Hold rod end 9 and turn rod 8 until pin 7 will assemble through rod end 9 and rod eye 10 6 Adjust the parking brake valve bracket to center rod 8 in the tube 7 Hold rod end 9 and turn rod 8 until pin 7 is firmly bottomed resistance is felt in the slot in rod eye 10 Then turn rod 8 1 4 turn in the oppos
40. llar 20 engages the eccentric on bearing 21 and the two parts are locked together 5 Place a punch or drift in the blind hole in collar 20 and strike it sharply with a hammer in the clockwise direction 6 Tighten the setscrew in collar 20 Forward Reverse Assembly Procedure 1 Engage the parking brake 2 Move the transmission direction selector spool to the NEUTRAL position middle detent 3 Assemble cable 13 to cover 14 and rod end Adjust cable 13 to dimension 15 shown in View E E 4 Adjust cable 13 to allow free fit of pin assembly 18 into the transmission bellcrank To adjust the cable remove bolts that hold cover 14 to the housing Loosen the locknut on cable 13 and turn cover 14 as necessary https sisweb cat com sisweb sisweb techdoc techdoc_print_page jsp returnurl sisweb si 2 25 2011 D6H amp D6H LGP TRACTORS POWER SHIFT 7PCO0001 UP MACHINE POW Page 59 of 64 Speed Control Assembly Procedure 1 Assemble cable 12 to cover 17 and rod end Adjust cable 12 to dimension 16 shown in View E E 2 Move the transmission speed selector spool to the SECOND gear position middle detent 3 Turn handle 5 to the SECOND gear position white mark on handle aligned with the number 2 on speed collar 4 Adjust cable 12 to allow free fit of pin assembly 19 into the transmission bellcrank To adjust the cable remove bolts that hold cover 17 to the housing Loosen the loc
41. nector 4 on the Test Tee This makes the pump outlet the load signal to the compensator valve 6 Connect a 1U5755 Hose Assembly to pressure tap 2 Connect the nipple assembly to the other end of the hose assembly and put this end in a container to collect oil 7 Make sure the transmission is in NEUTRAL and the parking brake is ON Move the governor lever to the OFF position so the engine will not start With the bulldozer control lever held in the RAISE position turn crank the engine over with the starter until a clear stream of oil comes out of the hose assembly This will remove purge any air that is in the signal line NOTE The bulldozer blade will raise when the engine is turned cranked over 8 Stop turning cranking the engine and lower the bulldozer blade to the ground Remove the nipple assembly from the hose assembly and connect the hose assembly to the elbow side of the 1U5793 Pressure Differential Delta P Gauge 9 Connect the other end of 1U5755 Hose Assembly on pressure tap 5 to the tee side of the delta P Delta P gauge Put a 0 to 60 000 kPa 0 to 8700 psi pressure gauge on the other pressure tap on the tee side of the Delta P gauge 10 Move the governor lever to the DECELERATE position With the bulldozer control lever in the RAISE position start the engine NOTE The bulldozer blade will raise when the engine is started https sisweb cat com sisweb sisweb techdoc techdoc_print_page jsp returnurl sis
42. nes the correct size of spacer to get the distance B between the center pin center of pivot head and the centering pin 12 With the correct distance B clearance C between spacer 3 and center pin 4 will be 0 10 to 0 25 mm 004 to 010 in https sisweb cat com sisweb sisweb techdoc techdoc_print_page jsp returnurl sisweb si 2 25 2011 D6H amp D6H LGP TRACTORS POWER SHIFT 7PCO0001 UP MACHINE POW Page 35 of 64 GZ Z l Setup Of Dial Indicator 13 Blocks gauge 19 Support Place support 19 on a surface plate Using gauge blocks 13 build up the dimension B as listed in the above chart Set up the dial indicator and zero https sisweb cat com sisweb sisweb techdoc techdoc_print_page jsp returnurl sisweb si 2 25 2011 D6H amp D6H LGP TRACTORS POWER SHIFT 7PCO0001 UP MACHINE POW Page 36 of 64 C6273P1E Installation Of Spacer 1 Plate port 2 Barrel cylinder 3 Spacer 20 Wire 21 Cylinder Using a piece of wire 20 guide the spacer 3 minimum thickness into center pin cylinder 21 of barrel 2 Place center pin in cylinder 21 without compression springs 5 NOTICE To avoid damage to center pin 4 and support 19 in the next step place measuring kit cylinder 24 over support and lay cylinder on its side horizontal https sisweb cat com sisweb sisweb techdoc techdoc_print_page jsp returnurl sisweb si 2 25 2011 D6H amp D6H LGP TRACTORS
43. ng are given in the Implement and Steering Hydraulic System Testing and Adjusting Visual Checks Do not check for leaks with your hands Pin hole very small leaks can result in a high velocity oil stream that will be invisible close to the hose This oil can penetrate the skin and cause personal injury Use cardboard or paper to locate pin hole leaks in pump or motor hoses during steer stall condition A visual inspection of the implement and steering hydraulic system and its components is the first step when a diagnosis of a problem is made Stop the engine lower the blade and the ripper to the ground To remove the tank filler cap slowly turn the filler cap until it is loose If oil comes out the bleed hole let the tank pressure lower before the filler cap is removed Make the following inspections 1 Measure the oil level 2 Look for air in the oil that is in the tank Do this immediately after the machine is stopped Use a clear bottle or container to get a sample of the oil Look for air bubbles in the oil that is in the bottle 3 Remove the filter elements and look for particles removed from the oil by the filter element A magnet will separate ferrous particles from nonferrous particles piston rings O ring seals etc 4 Inspect all oil lines and connections for damage or leaks 5 Inspect control linkage for bent broken or damaged components Troubleshooting Problem Checklist Hydraulic System Problem List
44. nt 1U7564 Hex Wrench 5 mm 6V9097 Combination Wrench https sisweb cat com sisweb sisweb techdoc techdoc_print_page jsp returnurl sisweb si 2 25 2011 D6H amp D6H LGP TRACTORS POWER SHIFT 7PCO0001 UP MACHINE POW Page 23 of 64 eG AO sh NS aie Re C19140FP2 Cross Section of Margin Spool in the Compensator Valve 1 Spool margin 2 Springs 3 Plug 4 Stop 5 Nut If after a margin pressure test an adjustment to the margin spool needs to be done do the following procedure 1 Lower all implements to the ground 2 Shut off the engine and move all the implement and steering control levers to release system pressure 3 Hold stop 1 with a 5 mm hex wrench and loosen nut 5 with a 17 mm combination wrench Turn stop 1 counterclockwise to decrease pressure setting and clockwise to increase the setting One revolution of stop 1 will change the pressure setting approximately 3500 kPa 510 psi 4 When the pressure setting is adjusted hold stop 1 with hex wrench and tighten nut 5 to a torque of 25 5 N m 18 4 lb ft 5 Do the Margin Pressure Test again to make sure the differential pressure setting is 2100 70 kPa 305 10 psi Pressure Tests of Pressure Limiter Valves Make reference to WARNING on the first page of the Implement and Steering Hydraulic System Testing and Adjusting section https sisweb cat com sisweb sisweb techdoc techdoc_print_page jsp returnurl sisweb si
45. ntial pressure setting should be held to 2100 70 kPa 305 10 psi Pump Load Test This test is a final test to determine if the pump or compensator valve is bad This test should be done only after the compensator valve and main relief valve have been checked for correct operation 1U5796 Pressure Differential Delta P Gauge Group Test Tee See Note 6V9829 Cap Assembly6V3965 Nipple Assembly NOTE The Test Tee must be assembled from parts shown in illustration C21314P1 The 6V8636 Connector must be drilled and tapped before the 6T0421 Orifice Plug 1 16 in 27 NPT can be installed This orifice plug must be installed in the 9 16 in THD end of the connector with a 4 mm 16 hex wrench 1 Remove the floor plate from the machine a SP Er https sisweb cat com sisweb sisweb techdoc techdoc_print_page jsp returnurl sisweb si 2 25 2011 D6H amp D6H LGP TRACTORS POWER SHIFT 7PCO0001 UP MACHINE POW Page 20 of 64 Hydraulic Pump 1 Tap pump discharge pressure 2 Tap signal oil Pressure 3 Line signal 2 Connect one end of a 1U5755 Hose Assembly to pressure tap 5 on the Test Tee 3 Connect coupler 6 on the Test Tee to pressure tap 1 6V9601 ADAPTER PUT 5349S THREAD SEALANT ON THOS Test Tee 4 Tap Pressure 5 Connector 6 Coupler 4 Disconnect signal line 3 from the elbow on the inlet manifold Put the 6V9829 Cap Assembly on the elbow 5 Connect signal line 3 to con
46. on and correction of problems in the implement and steering hydraulic system When more checks are necessary use the 8T5320 Hydraulic Test Group and the 4C4890 4C4892 Fitting Groups a stop watch a magnet a thermometer and a mm inch ruler for basic tests to measure 1 The opening pressure of the pressure limiter valves for the implement circuits and pump cut off valve for the steering circuit Pressure limiter valve and pump cut off valve pressures that are too low will cause a decrease in the lift dig rip and steering characteristics of the machine Opening pressures that are too high will cause a decrease in the life of hoses and components 2 Drift rates in the implement circuits Circuit drift is caused by leakage past cylinder pistons control valve spools load check valves or make up valves Excessive drift can be caused by problem with any one or combination of components 3 Cycle times in the implement circuits Cycle times that are longer than shown in the charts are the result of leakage pump wear and or pump speed rpm If the basic operation checks indicate excessive circuit leakage then pressure tests are needed to determine which components have a problem https sisweb cat com sisweb sisweb techdoc techdoc_print_page jsp returnurl sisweb si 2 25 2011 D6H amp D6H LGP TRACTORS POWER SHIFT 7PCO00001 UP MACHINE POWER Page 3 of 64 NOTE Locations of the pressure taps and procedures for testing and adjusti
47. pressure stall will tell if the pressure cut off spool needs to be adjusted The margin pressure test will tell if the margin spool needs to be adjusted Pressure Cut Off Spool Adjustment 1U7564 Hex Wrench 5 mm 6V9097 Combination Wrench https sisweb cat com sisweb sisweb techdoc techdoc_print_page jsp returnurl sisweb si 2 25 2011 D6H amp D6H LGP TRACTORS POWER SHIFT 7PCO0001 UP MACHINE POW Page 22 of 64 Cp Dat SSAA AT ie Ti Sif LZ C14768P2 Cross Section of Pressure Cut Off Spool in the Compensator Valve 1 Stop 2 Spring 3 Spool pressure cut off 4 Cap 5 Nut If after a high pressure stall test an adjustment to the pressure cut off spool needs to be done do the following procedure 1 Lower all implements to the ground 2 Shut off the engine and move all the implement and steering control levers to release system pressure 3 HOLD stop 1 with a 5 mm hex wrench and loosen nut 5 with a 17 mm combination wrench Turn stop 1 counterclockwise to decrease pressure setting and clockwise to increase the setting One revolution of stop 1 will change the pressure setting approximately 3500 kPa 510 psi 4 When the pressure setting is adjusted hold stop 1 with hex wrench and tighten nut 5 to a torque of 25 5 N m 18 4 lb ft 5 Do the High Pressure Stall Test again to make sure the pressure setting is 38 500 550 kPa 5575 80 psi Margin Spool Adjustme
48. rol valve 3 Seal on plug at the end of the steering valve spool 4 Seals on sleeve behind priority flow control valve spring in the steering control valve 5 Dirt or foreign material in orifice in signal line between the inlet manifold and compensator valve 6 Compensator valve Do the Pump Load Test to make sure 7 Steering valve spool or spool bore badly scratched If reading B is not correct and reading A is correct or too low this indicates excessive power use by the pump in the Steer Stall Condition The causes for this could be the following 1 Setting of main relief valve is too low or valve is leaking See Main Relief And Crossover Relief Valve Tests in this section 2 Setting of crossover relief valve s in counterbalance valve is are too low See Main Relief And Crossover Relief Valve Tests in this section 3 Makeup valves in steering control valve are leaking 4 Pump is failed Do a Pump Load Test to make sure 5 Steering motor is failed https sisweb cat com sisweb sisweb techdoc techdoc_print_page jsp returnurl sisweb si 2 25 2011 D6H amp D6H LGP TRACTORS POWER SHIFT 7PCO0001 UP MACHINE POW Page 17 of 64 15 Do Steps 10 through 13 again with the steering handle at the MID STEER LEFT position 16 Remove test equipment after all tests adjustments and needed repairs are completed Pump Discharge Pressure Tests Make reference to WARNING on the first page of the Implement and Steering H
49. ssure reading is correct or too low this indicates a leak s in the signal network See Diagnostic Instrument Tests for more information https sisweb cat com sisweb sisweb techdoc techdoc_print_page jsp returnurl sisweb si 2 25 2011 D6H amp D6H LGP TRACTORS POWER SHIFT 7PCO0001 UP MACHINE POW Page 19 of 64 Margin Pressure Test 1U5796 Pressure Differential Delta P Gauge Group 1 Remove the floor plate from the machine 2 Install a 1U5755 Hose Assembly on pressure tap 1 and 2 Connect the other ends of hoses to the 1U5793 Delta P Delta P Gauge Connect the hose from pressure tap 1 to the tee side of the Delta P gauge Connect the hose from pressure tap 2 to the elbow side of the Delta P gauge 3 Install the 8T0861 Gauge on the tee side of the Delta P gauge 4 Install the floor plate 5 Start and run the engine at maximum rpm Make sure the parking brake is ON and the transmission in NEUTRAL 6 Move the bulldozer control lever to a position in between HOLD and FULL RAISE positions Read the pressure on the Delta P gauge This is the margin pressure or the difference between pump discharge pressure and the signal pressure from the control valve The margin pressure should be 2100 275 kPa 305 40 psi 7 If the margin pressure is not correct then see Compensator Valve Adjustments Margin Pressure Adjustment for the correct procedure to make an adjustment If the margin pressure is adjusted the differe
50. ssure taps for testing the power train hydraulic system have quick disconnect couplings already installed Do not connect or disconnect the couplings when there is pressure in the system This will prevent damage to the seal that is in the coupling https sisweb cat com sisweb sisweb techdoc techdoc_print_page jsp returnurl sisweb si 2 25 2011 D6H amp D6H LGP TRACTORS POWER SHIFT 7PCO0001 UP MACHINE POW Page 40 of 64 PIR EP EEE EELS Na Power Train Hydraulic System Schematic 1 Valve priority 2 Spool speed selector 3 Valve selector and pressure control 4 Valve modulation relief 5 Piston load 6 Valve pressure differential 7 Spool direction selector 8 Valve ratio 9 Breather 10 Converter torque 11 Sump torque converter 12 Drive pump 13 Valve torque converter outlet relief 14 Cooler oil 15 Line transmission lubrication 16 Valve parking brake 17 Filter transmission oil 18 Pump oil 19 Sump transmission 20 Passage brake lubrication 21 Passage brakes 22 Valve service brake control 23 Sump case A Tap torque converter inlet pressure B Tap P1 pressure C Tap P2 pressure E Tap torque converter outlet pressure G Tap brake pressure J Tap pump pressure K Tap pump drive lube pressure NOTE Speed selector spool 6 has a NEUTRAL detent position This is for earlier models only later models do not
51. sted linkage 2 Leakage in and around the seals on the piston in the cylinder s affected 3 Leakage past a makeup valve or failed makeup valve seals for the affected circuit bulldozer lift and ripper lift control valves 4 The quick drop valve or end of stroke bypasses may be leaking Problem 3 Implement cycle times are too fast Probable Cause 1 Margin spool in compensator valve set too high 2 Flow control valve s failed Problem 4 Excessive pause time at ground line when powering blade down Probable Cause https sisweb cat com sisweb sisweb techdoc techdoc_print_page jsp returnurl sisweb si 2 25 2011 D6H amp D6H LGP TRACTORS POWER SHIFT 7PCO0001 UP MACHINE POWER Page 7 of 64 1 Quick drop not operating correctly 2 Charging valve stuck open 3 Makeup valve stuck open Mechanic s Chack And Data Shest For Use When Troubleshooting Steering System Hydraulic Problems O ll Levels Linkage Correctly Adjusted D Steering Turn Diameter Steer Lett mjt vith blada Wet Mh LJ Low Pressure Standby kPa psi O Margin Pressure kPa pai CL Engine No Load Maximum RPM rpm O Steer Stall Test Steer Left Pump Discharge Pressure No Load Engine RPM maximum Steer Stall Engine RPM Difference Between No Laad APM and Steer Stall APM Pump Differential Pressure 4 P At Steer Stall Tractor Serial Date Service Meter Hours Steer Right mitt with blade lift m MIR
52. t 5 out 1 2 turn and secure in place with locknut 6 https sisweb cat com sisweb sisweb techdoc techdoc_print_page jsp returnurl sisweb si 2 25 2011 D6H amp D6H LGP TRACTORS POWER SHIFT 7PCO0001 UP MACHINE POW Page 55 of 64 Parking Brake Earlier Models C21275P3 Parking Brake Linkage 1 Rod assembly 2 Locknuts 3 Valve parking brake control 2 Torque for locknut 14 4 N m 10 3 1b ft Procedure to Adjust Parking Brake 1 Check brake pressure at pressure tap G see transmission pressure chart with the parking brake lever in the ON and OFF positions 2 The brake pressure with the parking brake lever in the ON position should be 0 kPa 0 psi If not make rod assembly 1 longer 3 The brake pressure with the parking brake lever in the OFF position should be 2825 140 410 20 psi If not make rod assembly 1 shorter 4 Do Step 1 again if rod assembly adjustments were needed https sisweb cat com sisweb sisweb techdoc techdoc_print_page jsp returnurl sisweb si 2 25 2011 D6H amp D6H LGP TRACTORS POWER SHIFT 7PCO0001 UP MACHINE POW Page 56 of 64 Steering And Transmission Directional Control Series IT corar Dea Do not make any adjustment to the control linkage with the engine running Accidental disengagement of the parking brake while the engine is running could cause sudden machine movement and personal injury Torque for all 1 4 in lockn
53. uck open or has failed seals 6 Signal line orifice to pump restricted https sisweb cat com sisweb sisweb techdoc techdoc_print_page jsp returnurl sisweb si 2 25 2011 D6H amp D6H LGP TRACTORS POWER SHIFT 7PCO0001 UP MACHINE POWER Page 6 of 64 7 Internal signal leak A Shuttle valve will not move stuck or has failed seals B Flow control sleeve behind flow control spring has failed seals C Plug in end of steering valve spool is leaking 8 Pressure cutoff spool in compensator valve is set too low 9 Excessive internal leakage in pump and or steering motor Problem 4 Machine turns when steering control handle is released Probable Cause 1 Steering control linkage loose or not correctly adjusted 2 Steering valve spool is sticky Implement Problem 1 Implement cycle times are too slow machine not being steered Probable Cause 1 Implement valve spool is not fully shifted 2 Margin spool in compensator valve set too low 3 Blockage or leakage in signal network A Shuttle valve stuck open or has failed seals B Flow control sleeve behind flow control spring has failed seals C Plug in end of a control valve spool has a failed seal D Pressure limiter poppet valve leaking or failed seals on valve body Problem 2 Too much implement drift Probable Cause 1 The valve spool in the control valve is not correctly centered This problem can be caused by a broken spring or sticky valve spool or misadju
54. uts on cable assembly that hold the rod ends in place 8 2 N m 6 1 5 lb ft 1 See Steering And Transmission Hand Control Group for adjustment procedures 2 Assembled length of rod assembly 880 mm 34 6 in 3 Assembled length of rod assembly 280 0 1 5 mm 11 02 06 in 4 Torque for bolts 30 7 N m 22 5 lb ft https sisweb cat com sisweb sisweb techdoc techdoc_print_page jsp returnurl sisweb si 2 25 2011 D6H amp D6H LGP TRACTORS POWER SHIFT 7PCO0001 UP MACHINE POW Page 57 of 64 6 Torque for nut 30 7 N m 22 5 lb ft 11 Torque for nut 30 7 N m 22 5 lb ft 15 16 Dimension 12 2 mm 47 08 in 23 Depth to install bearing 4 5 1 5 mm 18 06 in _ NS SAG https sisweb cat com sisweb sisweb techdoc techdoc_print_page jsp returnurl sisweb si 2 25 2011 D6H amp D6H LGP TRACTORS POWER SHIFT 7PCO0001 UP MACHINE POW Page 58 of 64 t9 Steering And Transmission Hand Control Installation Procedure 1 Make any necessary adjustments to the Steering And Transmission Hand Control Group 2 Install control group 1 into the vehicle along with collar 20 bearing 21 and two flanges 22 3 With bearing 21 between two flanges 22 install bolts 4 to flanges 22 shown in View B B Tighten bolts 4 to 30 7 N m 22 5 lb ft 4 Turn collar 20 quickly clockwise as viewed from the top until the eccentric groove in co
55. vel at both turn positions before the steering linkage stops bottoms out Procedure For Adjustment Of Transmission Directional Control Linkage 1 Install assembled and adjusted rod assembly C through shaft assembly 2 Install shaft assembly 14 and lever 9 Make sure lever 9 and shaft assembly plate 12 part of shaft assembly 14 are parallel https sisweb cat com sisweb sisweb techdoc techdoc_print_page jsp returnurl sisweb si 2 25 2011 D6H amp D6H LGP TRACTORS POWER SHIFT 7PCO0001 UP MACHINE POW Page 52 of 64 2 Install cable assembly D and adjust to dimensions E and F Dimension E 16 2 mm 63 08 in is the distance from the top of cover 7 to the end of threads on cable Dimension F 12 2 mm 47 08 in is the distance from the end of rod end to the end of threads on cable 3 Install collar 11 and handle 10 on shaft assembly 14 so timing mark on handle is perpendicular within 5 to shaft assembly plate 12 4 Put handle 10 in NEUTRAL position If timing mark on handle is not vertical within 2 then adjust cable assembly D To adjust cable assembly remove bolts 5 and loosen locknut 6 Turn cover 7 to move timing mark to vertical position 5 With handle 10 in NEUTRAL position adjust collar 11 to line up NEUTRAL symbol on collar with timing mark on handle Service Brake Pedal Earlier Models Do not make any adjustments to the control linkage with the eng
56. ver Relief Valves Test The pressure settings for the main relief and crossover relief valves located on the counterbalance valve are higher than the pumps cut off pressure setting Therefore normal system pressures will not open these relief valves A test to check for low pressure settings can be done by checking engine rpm during given conditions Make reference to WARNING on the first page of the Implement and Steering Hydraulic System Testing and Adjusting section Also do not attempt to adjust the main relief or crossover relief valves on the machine with the engine running https sisweb cat com sisweb sisweb techdoc techdoc_print_page jsp returnurl sisweb si 2 25 2011 D6H amp D6H LGP TRACTORS POWER SHIFT 7PCO0001 UP MACHINE POW Page 29 of 64 6V3121 Multitach Group 1 Move the machine to an open area lower all implements to the ground engage parking brake and stop engine 2 Install 6V3121 Multitach on the tach drive 3 Start and run engine at maximum rpm 4 Record the maximum rpm reading on the tach 5 Release parking brake and engage service brakes Move the steering control handle to mid steer left position and then to mid steer right position 6 Record the rpm reading on the tach at each control handle position If the difference in the rpm readings from maximum rpm is more than 50 rpm at both control handle positions then the main relief or both crossover relief valves may have low pressure setting
57. ver possible perform tests with oil temperature below 66 C 150 F to prevent serious burns Do not hold gauges in hand or lap when recording pressure readings https sisweb cat com sisweb sisweb techdoc techdoc_print_page jsp returnurl sisweb si 2 25 2011 D6H amp D6H LGP TRACTORS POWER SHIFT 7PCO0001 UP MACHINE POW Page 15 of 64 This test is used mainly to determine where a problem may exist in the steering hydraulic circuit It also gives some indication of a problem in an implement circuit 1U5796 Pressure Differential Delta P Gauge Group 6V3121 Multitach Group 1 Move the machine to a flat and open area Lower all implements to the ground and stop engine 2 Remove floor plate and install a 1U5755 Hose Assembly on pressure tap 1 and 2 Hydraulic Pump 1 Tap pump discharge Pressure 2 Tap signal oil pressure 3 Connect the other ends of the hoses to the 1U5793 Delta P Delta P Gauge Connect the hose from pressure tap 1 to the tee side of the Delta P gauge Connect the hose from pressure tap 2 to the elbow side of the Delta P gauge 4 Install a 60 000 kPa 8700 psi gauge on the tee side of the Delta P gauge 5 Make sure the steering linkage is correctly adjusted See Low Pressure Standby Test in this section 6 Install the floor plate 7 Install multitach on the engines tach drive 8 Start and run the engine at maximum rpm Record rpm the reading should be 2075 50 rpm Check Vehicl
58. web si 2 25 2011 D6H amp D6H LGP TRACTORS POWER SHIFT 7PCO00001 UP MACHINE POW Page 21 of 64 11 After the engine starts move the bulldozer control lever to the HOLD position This puts the pump in the high pressure stall condition Record the pressure readings on both pressure gauges and stop the engine 12 The pressure readings on the gauges should be as follows A Pump discharge reading gauge on the tee side of the Delta P gauge should be 38 500 550 kPa 5575 80 psi B Pressure differential reading Delta P gauge should be 550 kPa 80 psi or less If the engine stalls dies when the bulldozer control lever is moved to the HOLD position the pump is failed and should be replaced If reading A is low and reading B is correct the compensator valve should be adjusted and Steps 10 and 11 should be done again See Compensator Adjustments Pressure Cutoff Spool Adjustment in this section If the pump discharge pressure can not be increased through adjustments to the compensator valve the pump is failed and should be replaced If reading B is high the compensator valve should be replaced Compensator Valve Adjustments Make reference to WARNING on the first page of the Implement and Steering Hydraulic System Testing and Adjusting section Do not make compensator valve adjustments with the engine running The compensator valve on the pump can be tested by running one of the pump discharge tests The high
59. ydraulic System Testing and Adjusting section Also always replace floor plate when performing tests and whenever possible perform tests with oil temperature below 66 C 150 F to prevent serious burns Do not hold pressure gauges in hand or lap when checking pressure readings Pump discharge pressures are known values and can be tested These tests are low pressure standby test high pressure stall test margin pressure test and pump load test Low Pressure Standby Test 6V7830 Tetragauge Group 1 Remove the floor plate from the machine Hydraulic Pump 1 Tap pressure 2 Install tetragauge on pressure tap 1 and install the floor plate 3 Start the engine and run at maximum rpm Make sure parking brake is in the ON position 4 Leave all control levers in the HOLD position 5 The pressure reading on the tetragauge should be approximately 3000 kPa 435 psi This is the pumps pressure output in the low pressure standby condition If the pressure reading is below 2100 https sisweb cat com sisweb sisweb techdoc techdoc_print_page jsp returnurl sisweb si 2 25 2011 D6H amp D6H LGP TRACTORS POWER SHIFT 7PCO0001 UP MACHINE POW Page 18 of 64 kPa 305 psi or above 3700 kPa 535 psi check the margin pressure setting See Margin Pressure Test in this section 6 Move the steering control handle back and forth against the stop in the parking brake linkage If the pressure reading on the tetragauge increases the
60. ylinder Bulldozer Lift Cylinder Drift Oil 28 to 48 C 49 to 68 C 69 to 88 C Temperature 83 to 118 F 120 to 155 F 156 to 190 F 2 7 17 minutes minutes Test No 1 Put the blade flat on the ground Raise the front of the machine off the ground by lowering the right side of the blade tilt right Put the tilt circuit in HOLD position Shut off engine and watch the tilt cylinder rod for movement Test No 2 https sisweb cat com sisweb sisweb techdoc techdoc_print_page jsp returnurl sisweb si 2 25 2011 D6H amp D6H LGP TRACTORS POWER SHIFT 7PCO0001 UP MACHINE POW Page 11 of 64 Put the blade flat on the ground Raise the front of the machine off the ground by lowering the left side of the blade tilt left Put the tilt circuit in HOLD position Shut off the engine and watch the tilt cylinder rod for movement Test Results Most Probable Causes Drifting occurs in Leakage between piston Tests No 1 and No 2 and cylinder Leakage between tilt circuit valve spool and body NOTE Remember that an O ring seal failure in the circuit will have the same effect as a major component failure Drift Tests for Ripper Lift Cylinder Ripper Lift Cylinder Drift Oil 28 to 48 C 49 to 68 C 69 to 88 C Temperature 83 to 118 F 120 to 155 F 156 to 190 F 5 2 7 1 7 minutes minutes minutes Test No 1 Raise the rear of the machine off the ground by lowering th

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