First/Reverse Brake Piston and Transmission Case Overhaul

DISASSEMBLY AND INSPECTION





1. Remove bearing and race assembly from transmission case.





2. Check first/reverse brake piston operation with compressed air. Piston should move smoothly and not bind or stick. If piston operation is incorrect, case or piston may require replacement.





3. Compress piston return springs with Tool 7539, or equivalent and remove piston snap ring.
4. Remove Tool 7539, or equivalent and remove piston return springs.
5. Remove No. 2 first-reverse brake piston with compressed air. Apply air through same transmission feed hole used for checking piston operation.





6. Remove reaction sleeve with Sleeve Remover Tool 7542, or equivalent. Insert tool flanges under sleeve and lift tool and sleeve out of case.





7. Remove No. 1 first/reverse brake piston with Piston Puller 7543, or equivalent. Slip tool under piston and lift tool and piston out of case.
8. Measure free length of piston return springs with springs mounted in retainer. Length should be 18.382 mm (0.724 inch). Replace springs if length is less than this.
9. Clean transmission case thoroughly with solvent and dry it with compressed air. Blow compressed air through oil feed passages to remove solvent residue and ensure that passages are clear. Inspect the case for wear or damage. Replace case if necessary.





ASSEMBLY
1. Lubricate and install new O-rings on No. 1 first/reverse brake piston and on reaction sleeve. Then install piston in sleeve.
2. Lubricate and install new O-ring on No. 2 brake piston.





3. Install assembled No. 1 piston and reaction sleeve on No. 2 piston.





4. Lubricate and install piston assembly in case. Align piston and case slots and press piston assembly into case with hand pressure.
5. Position piston return springs on No. 2 piston.
6. Compress piston return springs with Tool 7539, or equivalent and install piston snap ring. Be sure snap ring end gap is not aligned with any tangs on return spring retainer.
7. Verify piston operation with compressed air as outlined in disassembly procedure.
8. Coat bearing and race assembly with petroleum jelly and install it in piston assembly. Bearing and race assembly outer diameter is 57.7 mm (2.272 inch) and inner diameter is 39.2 mm (1.543 inch).