Symptom

Possible cause

Remedy/Prevention

No Braking Effect or Excessive Pedal Travel

Reservoir fluid level low

Check for causes of fluid leak, repair as required and refill the reservoir. Bleed the system as needed.

Air in the hydraulic system

Bleed the system.

Bleed screw loose or open

Bleed the system and tighten the bleed screw.

Caliper piston seal damaged

Disassemble the caliper and replace the piston seals. Replace the piston if it is damaged.

Excessive rotor runout or bent rotor

Check the rotor with a dial indicator. Install a new rotor if the runout exceeds the maximum specified.

Worn or excessively loose wheel bear- ings

Adjust or needed replace the bearings

Low quality brake fluid

Drain and clean the system. Replace with the recommended brake fluid.

Weak brake hose that expands under pressure

Replace the hoses.

Brake Noise (Chatter)

Excessive lateral runout of rotor

Check the runout with a dial indicator. Install a new rotor if the runout exceeds the maximum specified.

Lack of rotor parallelism

Check the parallelism with a microme- ter. Resurface or install a new rotor as required.

Loose wheel bearing

Readjust the bearing to the specified torque.

Brake Noise (Scraping)

Rust or mud build-up on edges of rotor and on caliper housing

Clean or replace as necessary.

Worn pad or pad installed backward

Replace the pads in the axle sets only with the friction surface against the rotor.

Incorrect caliper alignment permitting rotor to scrape on housing

Correct the alignment.

Brake Noise (Groan)

Pressure on the brake pedal too light

Slightly increase the pedal effort to eliminate the noise.

Brake Noise (Rattle)

Excessive clearance between the shoe and caliper

Install new pads.

Pad retainer spring missing or not cor- rectly positioned

Install a new pad retainer spring or position it correctly.

Brake Noise (Squeal)

Glazed pads

Resurface or replace the pads in the axle sets only.

Weak pad retainer spring

Install a new pad retainer spring.

Pad wear indicator contacting rotor

Install new pads in the axle sets only.

Foreign material embedded in linings

Replace the pads in the axle sets only.