HYDRAULIC AND PARK BRAKE SYSTEMS
Brake System Troubleshooting
Page 5-4
2005 HUV4420 Gasoline and HUV4420-D Diesel Vehicle Maintenance and Service Manual
5
Springy or spongy brake pedal – brake
pedal has soft, springy, or spongy feel
when pressed
Cracked or thin disc
Replace brake discs.
See Brake Disc
and Hub on page 5-10.
Poor quality brake fluid or water in fluid
Purge hydraulic fluid and fill with approved
DOT 5 (silicone) brake fluid.
See Purging
the Hydraulic System on page 5-23.
Weak (bulging) brake hoses that expand
under pressure
Check the master cylinder, brake lines,
and hoses for leaks or bulges. Replace all
damaged parts.
Air in the hydraulic system
See Bleeding the Hydraulic Brake
System on page 5-22.
Hard pedal – excessive pedal pressure
is required to stop the vehicle
Grease or brake fluid on the brake discs
or pads
Replace the hub or axle seal and replace
the brake pads.
See Brake Disc and Hub
on page 5-10.
Glazed brake pads
Replace the brake pads.
See Brake Pads
and Caliper on page 5-5.
Damaged or distorted brake pads
Replace the brake pads.
See Brake Pads
and Caliper on page 5-5.
Clogged hydraulic lines
Replace brake lines as required.
See
Hydraulic Line Replacement on
page 5-17.
Frozen master cylinder piston or bent rod
Replace master cylinder.
See Master
Cylinder and Reservoir on page 5-20.
Over-aggressive braking
Incorrect or distorted brake pads
Replace the brake pads.
See Brake Pads
and Caliper on page 5-5.
Vehicle pulls to one side
Incorrect or distorted brake pads
Replace the brake pads.
See Brake Pads
and Caliper on page 5-5.
Grease or brake fluid on the brake pads
Replace hub, axle seal, or caliper, and
replace the brake pads.
See Brake Disc
and Hub on page 5-10.
Scored or warped brake disc
Replace the brake disc.
See Brake Disc
and Hub on page 5-10.
Water on the brakes
Apply the brakes several times to dry the
brake pads and disc.
Sticking caliper piston
Replace the caliper.
See Brake Pads and
Caliper on page 5-5.
Faulty suspension parts or alignment
See Section 7 – Steering and Front
Suspension, or Section 9 – Rear
Suspension.
Pulsating brake pedal
Warped or worn brake discs
Replace the brake discs.
See Brake Disc
and Hub on page 5-10.
Bent wheel
Replace the wheel.
Worn or damaged wheel bearings
Replace bearings.
See Section 7 –
Steering and Front Suspension.
Decreasing brake pedal travel
Sticking caliper piston
Replace the caliper.
See Brake Pads and
Caliper on page 5-5.
Noise and chatter – clicking or
scraping sound upon brake application
Bent, damaged, or incorrect brake pads
Replace the brake pads
See Brake Pads
and Caliper on page 5-5.
Troubleshooting Guide continued on next page...
TROUBLESHOOTING GUIDE
SYMPTOM
POSSIBLE CAUSES
CORRECTIVE ACTION
Summary of Contents for HUV4420
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