TUBE AS 2169960 - Caterpillar

When the oil in the power train gets hot, it causes the air to expand and build up pressure in the power train oil tank.Pressure can remain in the power train oil tank after the engine and pumps are stopped.Personal injury can occur if pressure is not released before any service is performed on the power train.To prevent possible injury, remove the cap from the oil filler tube before any fitting, hose, or component in the power train is loosened, tightened, removed, and/or adjusted.The cap must be replaced when the tests and/or the adjustments are completed.The bucket and the other attachments must always be flat on the ground before service is performed.When it is necessary for an attachment to be raised while tests and/or adjustments are being performed, be sure the correct supports are in place. In the case of the bucket, it must be in the full DUMP position.Move the machine to a location away from the travel of other machines.Wear the seat belt, and be sure that other personnel are not near the machine when the engine is running and tests or adjustments are being performed.
Required Tools
Illustration 1 g00994631
Table 1
Required Tools    
Tool    Item    Part Number    Description    Qty    
A     A1     6V-4143     Coupler     2    
A2 6V-3989     Fitting     1    
A3 8T-0855     Pressure Gauge (
4000 kPa (580 psi))     1    
A4 177-7860     Hose As     1    Test Procedure
Illustration 2 g01032573
(A) Tooling (1) Pressure Tap (2) Charge Pressure Relief Valve (3) ECM Manifold
Connect tooling (A) to pressure tap (1) for the charge pressure.
Use calibration submode 20 to engage the brakes.
Do not hold the transmission control lever in the full FORWARD or REVERSE position for more than 5 seconds at any one time. Return the lever to the NEUTRAL position for at least 10 seconds in order to prevent extreme overheating of the oil in the drive pumps.
Do not stall the implements during hydraulic system warm-up. Stalling the implements causes oil to flow across the relief valve. This can damage the vane-type hydraulic pump when the system is cold. Before you allow the implements to stall, wait until the hydraulic system reaches operating temperature.
Start the engine and raise the temperature of the oil up to operating temperature. Run the engine at HIGH IDLE. Stall the transmission in five second intervals in order to warm the oil to the first mark on the temperature gauge. Wait for ten seconds after each stall of the transmission.
Use calibration submode 20 to disengage the brakes.
Run the engine at HIGH IDLE. The speed/direction control lever should be in the PARK position. The reading on the gauge is the pressure setting of the charge relief valve. The correct pressure setting of the charge relief valve is 2850 40 kPa (415 6 psi).If you need to adjust the pressure setting, perform the procedure in "Adjustment Procedure".Adjustment Procedure
Illustration 3 g01032605
(2) Charge Pressure Relief Valve (3) ECM Manifold
Stop the engine.
Remove