Toyota 4-Runner 1985 Repair Manual page 447

AUTOMATIC TRANSMISSION - Component Groups (Overdrive Case and Brake)
4. REMOVE THRUST BEARING AND RACES FROM
OVERDRIVE CASE
Note the position of the races.
AT-45
5. REMOVE SNAP RING, SPRING RETAINER AND RETURN
SPRINGS
6. REMOVE BRAKE PISTON
Blow compressed air through the case hole indicated in the
figure to pop out the brake piston.
If piston does not pop out, lift it out with needle-nose pliers.
7. REMOVE TWO OIL SEAL RINGS FROM OVERDRIVE CASE
8. REMOVE O-RINGS FROM PISTON
INSPECTION OF OVERDRIVE CASE AND BRAKE
NOTE: Do not allow the discs to dry out.
Prepare new discs by soaking them at least two hours in
ATF.
ASSEMBLY OF OVERDRIVE CASE AND BRAKE
(See page AT-44)
1. INSTALL TWO OIL SEAL RINGS ON OVERDRIVE CASE
Spread apart and slide them into the groove. Hook both
ends by hand.
2. INSTALL NEW O-RINGS ON PISTON
3. INSTALL BRAKE PISTON IN OVERDRIVE CASE
Install the piston with the cup side up, being careful not
to damage the O-rings.
4. INSTALL RETURN SPRINGS AND SET RETAINER AND
SNAP RING IN PLACE
Check that the ends of the snap ring are not aligned with
one of the cutouts.