CONTROL GP-ELECTRONIC 4589392 - Caterpillar

Drive the machine to a smooth, horizontal surface.
Illustration 1 g02544624
Move propel lever (1) to the NEUTRAL position.
Rotate speed dial (4) to the MINIMUM position.
Move parking brake switch (2) to the ON position.
Move propel mode switch (3) to the PAVE position.Note: The machine must be in PAVE mode in order to operate the screed lift system.
Illustration 2 g02544758
Move screed lift switch (5) to the FLOAT position. Allow the screed to lower to the ground.Note: The screed lift switch on both instrument panels must be in the FLOAT position in order for the screed to lower.
After the screed rests on the ground, move screed lift switch (5) to the HOLD position.
Illustration 3 g02547937
Move throttle control switch (6) to the LOW IDLE position. Hold the switch in this position for less than 1 second.
Illustration 4 g02549056
After the engine reaches low idle, move engine start switch (7) to the OFF position.
Assemble two sets of Tool (A). Assemble two sets of Tool (B) .
Connect one Tool (A) to each Tool (B) .
Illustration 5 g02558377
Open right access panel (8) on the right side of the machine.
Illustration 6 g02600117
Remove cap from fitting (9) in port "G" of the generator pump.
Connect Tool (B) to fitting (9) .
Illustration 7 g02600118
Remove the cap from case drain fitting (10) in port "L1" of the right propel pump.
Connect Tool (B) to fitting (10) .
Move engine start switch (7) to the START position. Release the engine start switch when the engine starts.
Move throttle control switch (6) to the HIGH IDLE position twice. For each switch actuation, hold the switch in this position for less than 1 second. The engine speed should increase to 2200 rpm.
Illustration 8 g02545141
Monitor the hydraulic oil temperature on the operator display. Operate the machine until the oil temperature reaches 43 5.6 °C (110 10 °F).
Record the pressure at port "G" (9) of the generator pump.
Record the case drain pressure at port "L1" (10) of the right propel pump.
Subtract the pressure recorded in Step 21 from the pressure recorded in Step 20. The differential pressure should be 2550 200 kPa (370 29 psi).
Move throttle control switch (6) to the LOW IDLE position. Hold the switch in this position for less than 1 second.
Move engine start switch (7) to the OFF position.
If the charge pressure is inside the specified range, go to Step 31. If the charge pressure is outside the specified range, go to Step 26.
Illustration 9 g02600121
Remove charge relief valve (10) .
Illustration 10 g02600126
Remove the following components from the pump case:
Poppet (14)
Shims (13)
Spring (12)
Add shims (13) to poppet (14) in order to increase the pressure. Remove shims in order to decrease the pressure.Note: A 1 mm (0.04 in) shim changes the charge pressure by 390 kPa (56.5 psi).
Install the following components in the pump housing:
Spring (12)
Shims (13)
Poppet (14)
Valve (11)
Go to Step 17.
Remove the tooling and replace cap on fitting (9). Remove the tooling and replace cap on fitting (10) .
Close right access panel (8).