SHAFT-AXLE 3188626 - Caterpillar

Hydraulic oil pressure can remain in the hydraulic systems after the engine and pump have been stopped. Serious injury can be caused if this pressure is not released before any service is done on the hydraulic systems. To prevent possible injury, refer to the section, Testing and Adjusting, "Hydraulic System Pressure - Release" before any fitting, hose or component is loosened, tightened, removed or adjusted.When possible, the bucket or attachment must always be lowered to the ground before service is started. When it is necessary for the boom to be in the raised position while tests or adjustments are done, be sure that the boom, stick and bucket or attachment have correct support.The swing lock (if equipped) must be engaged before service is started.Always move the machine to a location away from the travel of other machines. Be sure that other personnel are not near the machine when the engine is running and tests or adjustments are being made.
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.
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 g01161467
Tooling (A)
Table 1
Required Tools    
Tooling    Item    Part
Number    Description    Qty    
A     A1     8T-0855     Pressure Gauge
0 to 4000 kPa (0 to 580 psi)     1    
A2 6V-3989     Fitting     1    
A3 6V-4143     Coupler     2    
A4 177-7861     Hose As
0 to 6000 kPa (0 to 870 psi)     1    Test Procedure (Transmission Main Relief Valve)
Move the machine to a smooth horizontal location.
Lower all of the implements. Engage the parking brake. Turn the engine OFF.
Illustration 2 g01255465
(P) Pressure Tap for the Transmission Main Relief Valve (L1) Pressure Tap for the Transmission lubrication
Attach tooling (A) to pressure tap (P) .
Start the engine. Warm the power train oil to a temperature of 80° 10°C (176° 18°F).
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 pressure at tooling (A) should be 2830 140 kPa (410 20 psi).
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 pressure at tooling (A) should be 2585 105 kPa (375 15 psi).ReferenceRefer