4-37
2. TROUBLESHOOTING
2. TROUBLESHOOTING
SERVICE BRAKE
SERVICE BRAKE
Diagnose malfunction charts are arranged from most probable and simplest to verify, to least likely,
more difficult to verify. Remember the following steps when troubleshooting a problem :
Step 1. Operational check out procedure (see section 1)
Step 2. Operational checks (in this group)
Step 3. Troubleshooting
Step 4. Tests and adjustments (see group 3)
1)
1)
Problem
Cause
Remedy
Poor or no brakes
Poor or no brakes
Brake accumulator charge low.
Brake pump standby pressure
low.
Brake pressure low.
Air in system.
Worn brake surface material.
Leakage in brake valve.
Leakage in brake piston seal.
Do brake accumulator check.
Do brake pump standby pressure test.
Do brake valve pressure test.
Bleed brakes.
Inspect brake surface material.
Do brake valve leakage test.
Check for an over filled differential.
Apply brakes and check for leakage from check
plug.
※
It is normal for the oil level to be slightly
above the check plug.
Aggressive brakes
Aggressive brakes
Internal restriction in circuit.
Brake valve malfunction.
Low oil level.
Remove lines and components.
Disassemble and inspect.
Check oil level.
Brakes drag
Brakes drag
Brake pedal not retur ning
properly.
Debris holding valve partially
open in brake valve.
Warped brake disk.
Stuck brake piston.
Inspect floor mat and pedal.
Do brake valve pressure test.
Inspect brake disk.
Repair.
Brakes lock up
Brakes lock up
Brake valve malfunction.
Clean or replace brake valve.
Summary of Contents for HL955
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