Air Pressure Tests

DESCRIPTION
A no-drive condition can exist, even with correct transmission fluid pressure, because of inoperative clutches or bands. Refer to the Clutch/Band application chart to determine the appropriate elements. A clutch concern may be located by substituting air pressure for oil pressure to determine the location of the malfunction.

Example: When the transaxle range selector lever is in a forward gear range (D, 2, 1) a no-drive condition may be caused by an inoperative forward clutch.

PROCEDURE
1. Drain the transaxle. Remove main control cover.
2. Remove the main control as an assembly, with the solenoid body assembly.





3. The inoperative clutches may be located by applying air pressure into the appropriate clutch port. See diagram for clutch port locations.
4. Install Transmission Test Plate T94P-77000-S using 6 bolts (T32P-7006-C).
5. Apply air pressure 275 kPa (40 psi) to the appropriate clutch port (see diagram). A dull thud may be heard, or movement felt when the clutch piston is applied. If clutch seals or check balls are leaking, a hissing may be heard.

CAUTION: The coast clutch circuit should not be applied unless air pressure is maintained in the forward clutch circuit. Failure to do so may result in the coast clutch piston coming out of the forward clutch piston.

NOTE: Refer to Clutch/Band Application Chart 601.

TEST RESULTS
- If the servos do not operate, disassemble, clean and inspect them to locate the source of the concern.
- If air pressure applied to the clutch passages fails to operate a clutch, or operates clutches simultaneously, inspect the fluid passages in the case.
- If air pressure applied to the accumulator fails to operate an accumulator, remove and inspect case passages and piston.