ELECTRONICS GP-ENGINE RATINGS 2085706 - Caterpillar

Personal injury or death can result from sudden machine movement.Sudden movement of the machine can cause injury to persons on or near the machine.To prevent injury or death, make sure that the area around the machine is clear of personnel and obstructions before operating the machine.
Care must be taken to ensure that fluids are contained during performance of inspection, maintenance, testing, adjusting and repair of the machine. Be prepared to collect the fluid with suitable containers before opening any compartment or disassembling any component containing fluids.Refer to Special Publication, NENG2500, "Caterpillar Tools and Shop Products Guide", for tools and supplies suitable to collect and contain fluids in Caterpillar machines.Dispose of all fluids according to local regulations and mandates.
Specifications
Table 1
Pilot Pressure
Item Setting Actual
Pilot Pressure 2800 1000 kPa (406 145 psi) Introduction
This information includes the following test:
Pilot Pressure-Test and AdjustRequired Tools
Illustration 1 g03696346
Table 2
Required Tools
Tool Item Qty Part No Description
A 198-4240 Digital Pressure Indicator Gp
A1 1 198-4234 Digital Indicator
A2 1 198-4237 Pressure Sensor Gp
(0 to 3,445 kPa (0 to 500 psi))
A2 1 198-4238(1) Pressure Sensor Gp
(0 to 34,450 kPa (0 to 5,000 psi))
A2 1 198-4239 Pressure Sensor Gp
(0 to 41,368 kPa (0 to 6,000 psi))
A2 1 251-9600(2) Pressure Sensor Gp
(0 to 68,900 kPa (0 to 10,000 psi))
A3 1 198-4236 Adapter Cable As
(1) This sensor must be purchased separately, the sensor is not included in the 198-4240 Digital Pressure Indicator Gp
(2) This sensor can only be used on large diameter pressure taps like 6V-3965 Fitting.Test Preparation
Refer to Testing and Adjusting, "Machine Preparation for Testing and Adjusting".Refer to Testing and Adjusting, "System Pressure-Release".Pilot Pressure-Test and Adjust
Move the machine to a smooth level area that will support the weight of the machine.
Lower all attachments to the ground. Stop the engine.
Apply parking brake.
Release pressure from the hydraulic system.Refer to Testing and Adjusting, "System Pressure-Release".
Remove left-hand side plates under the cab to access the front manifold under the machine cab.
Illustration 2 g03809296
Location of the front manifold
(1) PLG1 tap
(2) Locknut
(3) PRV1 adjustment screw
Attach tooling "A" the test tap at port labeled "PLG1" (1) using the appropriate size gauge.
Start the engine and run at high idle. Bring the hydraulic oil up to normal operating temperature.
Run the engine at high idle. Raise the boom to a stalled position.
Pressure reading should be 2862 350 kPa (415 51 psi).
If the pressure reading is correct, proceed to Step 14.Note: When, the pilot pressure is adjusted the machine must be cycled. The cycling allows the accumulator to equalize the pressure in the system. If, pressure is not equalized the mechanic may get a false reading when pressure is checked.
Illustration 3 g03696398
If the pressure reading is not correct, locate PRV1 on the pilot manifold. Loosen locknut (2) and turn adjustment screw (3) clockwise in order to increase the relief valve setting. Turn adjustment screw (3) counterclockwise in order to decrease the relief valve setting.
After adjustment screw (3) is turned for an adjustment, tighten locknut (2)