Clutch Air Pressure Tests

CLUTCH AIR PRESSURE TESTS

Special Tools:















Inoperative clutches can be located using a series of tests by substituting air pressure for fluid pressure using Air Pressure Test Plate.

The clutches may be tested by applying air pressure to their respective passages. The valve body and oil filter must be removed and Air Pressure Test Plate installed. To make air pressure tests, proceed as follows:

NOTE: The compressed air supply must be free of all dirt and moisture. Use a pressure of 30 psi.

Remove oil pan and valve body, Install Test Plate and tighten bolts to 6 Nm (50 in. lbs.). When testing is finished install valve body and tighten bolts to 6 Nm (50 in. lbs.), Install the oil pan bolts and tighten to 6 Nm (50 in. lbs.) and fill transmission . Fluid/Filter Service

OVERDRIVE CLUTCH

Apply air pressure to the overdrive clutch feed hole located on the test plate marked OD, listen for an audible thud. The piston should return to its starting position when the air pressure is removed.

REVERSE CLUTCH

Apply air pressure to the reverse clutch feed hole located on the test plate marked REV , listen for an audible thud. The piston should return to its starting position when the air pressure is removed.

2/4 CLUTCH

Apply air pressure to the feed hole located on the test plate marked 2/4 clutch. listen for an audible thud. The piston should return to its original position after the air pressure is removed.

LOW/REVERSE CLUTCH

Apply air pressure to the low/reverse clutch feed hole located on the test plate marked LR. Then, listen for an audible thud. The piston should return to its original position after the air pressure is removed.

UNDERDRIVE CLUTCH

Because this clutch piston cannot be seen, its operation is checked by function. Air pressure is applied to the feed hole located on the test plate marked UD. This locks the output shaft. Use a piece of rubber hose wrapped around the input shaft and a pair of clamp-on pliers to turn the input shaft. Next apply air pressure to the underdrive clutch. The input shaft should not rotate with hand torque. Release the air pressure and confirm that the input shaft will rotate.

DIRECT CLUTCH

Apply air pressure to the feed hole located on the test plate marked DC, listen for an audible thud.

LOW CLUTCH

Apply air pressure to the feed hole located on the test plate marked LC, listen for an audible thud.