Husqvarna HUV4420 Service Manual page 42

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