Band Servo

Pre-Inspection

Band servo operation
1. Apply compressed air through the oil passage as shown.
2. Verify that the piston stem moves toward the brake band.

Air pressure: 390 kPa (4.0 kgf/sq.cm, 57 psi) max.

3. If not, the D-rings or the O-rings may be damaged or the piston assembly may be sticking. Inspect and replace as necessary when assembling replace as necessary when assembling.







Disassembly / Inspection / Assembly
1. Disassemble in the order shown in the figure, referring to Disassembly Note.
2. Inspect all parts and repair or replace as necessary.
3. Assemble in the reverse order of disassembly, referring to Assembly Procedure.

Disassembly note




Piston and servo piston retainer
Remove the piston and servo piston retainer from the transmission case by using a plastic hammer.




0/D band servo piston
1. Block one oil hole of the 0/D servo piston retainer and the center hole in the 0/D band servo piston.
2. Apply compressed air through the other oil hole in the 0/D servo piston retainer to remove 0/D band servo piston.

Air pressure: 390 kPa (4.0 kgf/sq.cm, 57 psi) max.

3. Remove the D-ring from the 0/D band servo piston.

Inspection

Return spring




1. Measure the spring free length.

Specification:

Specification

2. If not within specification, replace the return spring.

Assembly procedure




1. Apply ATF to new O-rings and Install them onto the servo piston retainer.
2. Apply ATF to new D-rings and Install them onto the band servo piston.






CAUTION: Do not deform the retaining ring.

3. Apply ATF to the servo spring retainer and retaining ring (large). Assemble them in the band servo piston.




4. Assemble the band servo piston, piston stem, return spring, and spring retainer.

CAUTION: Do not deform the retaining ring.

5. Install the retaining ring (small).






CAUTION: Apply even pressure to the perimeter of the piston when Installing it to avoid damaging the O-rings and D-rings.

6. Apply ATF to the band servo piston assembly and Install it onto the servo piston retainer.




7. Apply ATF to a new D-ring and Install it onto the 0/D band servo piston.






CAUTION: Apply even pressure to the perimeter of the piston when Installing it to avoid damaging the D-ring.

8. Apply ATF to the 0/D band servo piston, and Install it into the band servo retainer.




9. Install return springs A and B.

CAUTION: Apply even pressure to the perimeter of the body when Installing it to avoid damaging the O-rings and D-rings.

10. Apply ATF to the piston assembly and Install it into the transmission case.




11. Apply ATF to the band servo retainer and a new gasket, and Install them on the transmission case.




12. Tighten the bolts evenly and gradually in the order shown.

Tightening torque: 6.9 - 8.8 N.m (70 - 90 kgf.cm, 61 - 78 in.lbf)







13. Verify servo piston operation by applying compressed air through the oil holes as shown.

Air pressure: 390 kPa (4.0 kgf/sq.cm, 57 psi) max.