631E Series II, 633E Series II and 637E Series II Wheel Tractor Power Train Caterpillar

• The oil pressure to the transmission lubrication circuit is good.

• The oil pressure to the transmission lubrication circuit is good during the retarder operation (if equipped).

• The retarder control valve (if equipped) properly functions.

• The retarder (if equipped) properly functions.

Procedure

Illustration 1	g00635447
Transmission Lubrication and Torque Converter Outlet Pressure Tap. (N) Pressure tap for transmission lubrication (P) Pressure tap for torque converter outlet

1. At pressure tap (N), connect a hose group to the nipple assembly.

2. Connect 8T-0853 Pressure Gauge to the hose.

3. With the parking brake engaged, start and operate the engine at LOW IDLE rpm with the transmission in NEUTRAL. The pressure on the gauge should read a minimum of 7 kPa (1 psi).

4. With the transmission in NEUTRAL, operate the engine at HIGH IDLE rpm. The pressure on the gauge should be between 100 to 210 kPa (15 to 30 psi). Make sure that the retarder control lever (if equipped) is in RELEASED position.

   Note: Continue with Step 5 and Step 6 if you are testing a machine with a retarder.

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NOTICE
Be sure that the torque converter (transmission) oil does not get too hot.

5. While the engine is still operating at HIGH IDLE rpm, FULLY ACTIVATE the retarder by pulling the lever all the way toward you. The pressure on the gauge should be between 0 to 35 kPa (0 to 5 psi) of the pressure that was measured in Step 4. Make sure that the air pressure is correct.

6. Move the retarder control lever back to the RELEASED position by pushing the lever away from you. The pressure on the gauge should be identical to the pressure in Step 4.

Results

• When the retarder is not activated and the oil pressure is too low, perform the Systems Operation, Testing and Adjusting, "Torque Converter Outlet Relief Valve Pressure - Test".

• When the retarder is activated and the oil pressure decreases too much, the retarder has too much oil leakage.

• If the oil pressure in Step 6 is not identical to the oil pressure in Step 4, the retarder control valve is open or damaged.