Disassembly/Assembly

DISASSEMBLY

Fig. 5 Booster Mounting Fixture:

Fig. 6 Booster Body Tab Alignment:

Fig. 7 Removing Valve Stopper Key:

Fig. 8 Removing Booster Body Oil Seal:

1. Remove pushrod clevis and locknut.
2. Install brake booster to brake mounting fixture, Fig. 5. Ensure booster vacuum pipe is clear of mounting fixture base and the booster mounting nuts are not over tightened.
3. Turn fixture handle until No. 1 and No. 2 body tabs are aligned, Fig. 6.
4. Remove booster from fixture, then separate body No. 1 and No. 2. This step must be performed with care because there is spring pressure between body No. 1 and No. 2.
5. Remove booster piston spring, piston rod, boot, air cleaner and air cleaner separator from body No. 2.
6. Remove valve stopper key cushion from stopper key.
7. Compress air valve spring, then remove valve stopper key, Fig. 7.
8. Remove booster air valve assembly from booster piston. Do not disassemble booster air valve assembly.
9. Remove diaphragm ring from booster piston, then the reaction disc from booster piston rod.
10. Remove oil seal from booster body No. 2 using oil seal remover/installer tool No. J-24435-4, J34874 and J-7079-2 or equivalents, Fig. 8.
11. Inspect all parts for corrosion, nicks, cracks, cuts, scoring, distortion or excessive wear. Replace as necessary.
12. Clean all metal parts in ethyl alcohol. Do not immerse plastic and rubber components in ethyl alcohol. Wipe with a clean dry cloth. Dry with clean compressed air.

ASSEMBLY

Fig. 9 Installing Diaphragm & Booster Piston:

Fig. 10 Installing Booster Piston, Rod, Retainer & Spring:

1. Using silicone grease supplied in overhaul kit, grease the oil seal outer surface and inner lip, then install oil seal to booster body No. 2 using oil seal remover/installer tool No. J-24435-4, J34874 and J-7079-2 or equivalents, Fig. 8.
2. Install retainer to diaphragm, then booster piston rod to reaction disc.
3. Install diaphragm to booster piston, then the new diaphragm ring, Fig. 9.
4. Apply grease to booster air valve, then install air valve to booster piston.
5. Compress air valve and insert valve stopper key. Do not force air valve assembly.
6. Install valve stopper key cushions. Ensure stopper key cushions are installed in the proper direction and are seated into key notch.
7. Install booster piston to booster body No. 2.
8. Install air cleaner separator and air cleaner to rod of air valve assembly.
9. Install body boot to booster body No. 2. Ensure both ends of boot are fitted securely.
10. Grease outer face of reaction disc, then install it to the booster piston rod. Ensure there is no trapped air between the piston rod and reaction disc.
11. Assemble piston rod, rod retainer and piston return spring to booster piston and booster body No. 1, Fig. 10.
12. Mount booster to holding fixture then assembly body No. 1 and No. 2 together by turning tool handle counterclockwise until lock tabs are returned to their original position.
13. Install pushrod clevis and locknut. Torque locknut to 14.5-21.5 ft. lbs. Clevis brake pedal mounting hole must be 4.94-4.98 inches from booster mounting surface.