Chevrolet 1980 Light Duty Truck Service Manual page 359

CONDITION
Excessive Brake Pedal
Effort
Slow Brake Pedal
Return
Grabby Brakes
Booster Chatters -
Pedal Vibrates
Accumulator Leak
Down-System does
not hold charge
HYDRO — BOOST DIAGNOSIS
CAUSE
Loose or broken power steering pump belt.
No fluid in power steering reservoir.
Leaks in Hydro-Boost
Leaks at Hydro-Boost tube fittings.
External leakage at accumulator
Faulty booster piston seal causing leakage at
booster flange vent.
Faulty booster input rod seal with leakage at
input rod end.
Faulty booster cover seal with leakage
between housing and cover.
Faulty booster spool plug seal.
Excessive seal friction in booster.
Faulty spool action.
Restriction in return line from booster to
pump reservoir.
Damaged input rod end.
Faulty spool action caused by contamina­
tion in system.
Power steering pump belt slips.
Low fluid level in power /steering pump
reservoir.
Faulty spool operation caused by contamin­
ation in system.
Contamination in steering hydro-boost
system
Internal leakage in accumulator system
Fig. 5-2~Hydro-Boost Diagnosis
BRAKES
CORRECTION
Tighten or replace the belt.
Fill reservoir and check for external leaks.
Replace faulty parts.
Tighten fittings or replace tube seats, if
faulty.
Replace "0 " ring and retainer.
Overhaul with new seal or input rod and
piston assembly.
Overhaul with new seal kit.
Overhaul with new seal kit.
Overhaul with spool plug seal kit.
Overhaul with new seal kit.
Flush steering system while pumping brake
pedal.
Replace line.
Replace input rod and piston assembly.
Flush steering system while pumping brake
pedal.
Tighten belt.
Fill reservoir and check for external leaks.
Flush steering system while pumping brake
pedal.
Flush steering system while pumping brake
pedal
Overhaul unit using accumulator rebuild kit
and seal kit.
LIG H T T R U C K SERV ICE M AN UAL
5-5