4L80-E/4L85-E - Automatic Transmission

Pressure Regulator Replacement

Tools Required

J 36850 Transjel(R)

Removal Procedure

1. Raise the vehicle. Refer to Lifting and Jacking the Vehicle .
2. Remove the transmission oil pan and the filter.





Caution: Valve springs can be tightly compressed. Use care when removing retainers and plugs. Personal injury could result.

3. Remove the reverse boost valve bushing retainer ring (2).




4. Remove the following from the reverse boost valve cylinder:

* The reverse boost valve bushing
* The reverse boost valve
* The pressure regulator spring retainer
* The pressure regulator spring
* The pressure regulator valve
* The reverse boost valve bushing

Installation Procedure

1. Install the pressure regulator valve with J 36850 .




2. Pre-assemble the following parts:

* The reverse boost valve bushing
* A new reverse boost valve
* A new pressure regulator spring retainer
* The added isolator pressure regulator spring
* The pressure regulator spring

3. Install the pre-assembled parts into the pump bore.




4. Install the reverse boost valve bushing retainer ring while holding the reverse boost valve bushing in place.
Ensure the retainer ring (2) is in the groove.
5. Install the transmission oil pan and the oil filter.
6. Lower the vehicle.
7. Fill the transmission to the proper level with DEXRON(R) VI transmission fluid. Refer to Transmission Fluid Check .

Important: It is recommended that transmission adaptive pressure (TAP) information be reset.

Resetting the TAP values using a scan tool will erase all learned values in all cells. As a result, The ECM, PCM or TCM will need to relearn TAP values. Transmission performance may be affected as new TAP values are learned.

8. Reset the TAP values. Refer to Transmission Adaptive Functions .