PLATE 4701192 - Caterpillar

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.Dispose of all fluids according to local regulations and mandates.
Specifications
Table 1
Pressure Test for the Transmission Main Relief Valve
Date Equipment ID Code
Item Specification Actual
Low Idle (P) 2610 104 kPa (379 15 psi)
High Idle (P) 2800 138 kPa (406 20 psi)
(Tier II)
High Idle (P) 2780 138 kPa (403 20 psi)
(Tier III) Introduction
The main relief valve for the transmission maintains the maximum pressure of the oil that is delivered to the transmission clutches by the transmission modulating valves. Also, the main relief valve protects the transmission hydraulic system from any high-pressure spikes.The following test procedure will verify whether the pressure setting is within the specified limit. The adjustment procedure provides the information that is needed to adjust the main relief valve to the specified limit.Required Tools
Illustration 1 g02571852
Tooling (A)
Table 2
Required Tools
Tooling Item Part
Number Description QTY
A 198-4240 Digital Pressure Indicator Group
A1 198-4234 Digital Pressure Indicator 1
A2 198-4237 Pressure Sensor (0 to 500 psi) 1
A3 198-4236 Adapter Cable Assembly 1 Test Preparation
Move the machine to a smooth horizontal location.
Lower all the implements.
Shut off the engine.
Turn the key to the ON position. Make sure that the implement lockout switch is turned to the UNLOCKED position. Move the implement control levers to all positions several times to release any pressure in the hydraulic system.
Illustration 2 g03676780
(P) Pressure Tap for the Transmission Main Relief Valve
(L1) Pressure Tap for the Transmission Lubrication
Attach tooling (A) to pressure tap (P).Test Procedure
Start the engine. Warm the power train oil to a temperature of 80° 5°C (176° 9°F).
Operate the engine at LOW IDLE (800 rpm). Make sure that the steering control lever is in the NEUTRAL position. Engage the parking brake.
Check the pressure at tooling (A). The main relief pressure should be 2610 104 kPa (379 15 psi).
Operate the engine at HIGH IDLE. Make sure that the steering control lever is in the NEUTRAL position. Disengage the parking brake.
Check the pressure at tooling (A). The main relief pressure should be a specific pressure for certain machines. Check Table 1 for the correct pressure.
If the pressure at tooling (A) is within the specified limit, the test is complete. If the pressure at tooling (A) is not within the specified limit, perform the procedure in "Adjustment Procedure".Adjustment Procedure
Perform the steps in "Test Procedure".
Illustration 3 g03676782
(1) Bolts
(2) Back Cover
Remove bolts (1) from