K 2500 Truck 4WD V8-379 6.2L DSL VIN C FI (1989)
Hydraulic Brake Booster: Service and Repair
Bleeding Procedure
Hydro-Boost
1.
Fill oil reservoir to proper level and let stand at least two minutes.
2.
Start engine and run momentarily.
3.
Add oil as necessary.
4.
Repeat above procedure until oil level remains constant after running engine.
5.
Raise and support front of vehicle.
6.
Turn wheels left and right, lightly contacting stops.
7.
Add oil as necessary.
8.
Lower vehicle.
9.
Start engine and depress brake pedal several times while rotating steering wheel from stop to stop.
10.
Turn engine off, then pump brake pedal four or five times to deplete accumulator pressure.
11.
Check oil level, filling as necessary.
12.
If oil is extremely foamy, allow vehicle to stand several minutes with engine off, then repeat entire procedure.
Hydro-Boost II
1.
Fill power steering pump until fluid level is at base of pump reservoir neck.
2.
Disconnect 12 volt wire from injection pump or distributor, then crank engine for several seconds. Do not start engine.
3.
Check fluid level, adding as necessary.
4.
Connect 12 volt wire and start engine.
5.
Turn steering wheel from stop to stop, then turn off engine.
6.
Depress brake pedal four or five times to deplete accumulator vacuum.
7.
Check fluid level, adding as necessary.
8.
Start engine, turn steering wheel from stop to stop. Turn engine off, and check fluid level.
9.
If fluid is extremely foamy, stop engine and let vehicle stand for one hour, then check fluid level, adding as necessary.
