Diagnosis Of Hydro-Boost System - GMC 1986 P-Truck Service Manual

DIAGNOSIS OF HYDRO-BOOST SYSTEM

PROBLEM
Slow Brake Pedal 1.
Return. 2. Faulty spool action.
3. Restriction in return line from booster
4. Damaged input rod end.
Grabby Brakes. 1.
Booster Chatters - 2. Power steering pump belt slips.
Pedal Vibrates.
3. Low fluid level in power steering pump.
4. Faulty spool operation caused by con­
A ccum ulator Leak-
1.
down System does
not hold charge. 2. Internal leakage in accumulator sys­
POSSIBLE CAUSE
Excessive seal friction in booster.
to pump reservoir.
Faulty spool action caused by contami­
nation in system.
tamination in system.
Contamination in steering hydro-boost
system.
tem.
BRAKES 5-7
CORRECTION
Overhaul with new seal kit.
1.
2. Flush steering system while pumping
brake pedal.
3. Replace line.
4. Replace input rod and piston assem­
bly.
Flush steering system while pumping
1.
brake pedal.
2. Tighten belt.
3. Fill reservoir and check for external
leaks.
4. Flush steering system while pumping
brake pedal.
Flush steering system while pumping
1.
brake pedal.
2. Overhaul unit using accumulator re­
build kit and seal kit.