K 2500 Truck 4WD V8-379 6.2L DSL VIN C FI (1989)
Vacuum Brake Booster: Service and Repair
Booster Assembly
Single Diaphragm Type
Disassembly
Fig. 3 Exploded View Of Delco-Moraine Single Diaphragm Brake Booster Components
Fig. 4 Brake Booster Holding Fixture
1.
Remove boot, silencer, vacuum check valve, grommet and front housing seal, Fig. 3.
2.
Scribe a line across front and rear housing, then mount brake booster to brake mounting fixture tool No. J 23456 or equivalent, Fig. 4.
3.
Turn fixture handle counterclockwise to unlock housings.
4.
Remove return spring, power piston assembly and power piston bearing from rear housing, Fig. 3.
5.
Remove reaction body retainer, piston rod, reaction retainer and filter, Fig. 3.
6.
Remove power piston and pushrod assembly as follows:
a.
While holding the pushrod down against a hard surface, grasp outside edge of diaphragm support and diaphragm, Fig. 3.
b.
Use a slight force to dislodge diaphragm retainer, Fig. 3.
7.
Remove diaphragm from diaphragm support, Fig. 3.
8.
Inspect all parts for corrosion, nicks, cracks, cuts, scoring, distortion or excessive wear. Replace as necessary.
9.
Clean all parts in denatured alcohol. Dry with clean compressed air. Do not immerse power piston and pushrod assembly in alcohol.
Assembly
