HYDRAULIC AND PARK BRAKE SYSTEMS
Brake System Troubleshooting
2001 Pioneer 1200 Gasoline Vehicle Maintenance and Service Manual Page 6-5
6
Springy or spongy brake pedal –
Brake pedal has soft, springy or
spongy feel when depressed
Bent or distorted brake shoes
Replace the brake shoes. See Brake
Shoe Removal on page 6-9.
Cracked or thin drums
Replace brake drums. See Brake Drum
Removal on page 6-7.
Poor quality brake fluid (low boiling point)
Purge hydraulic fluid and fill with approved
DOT 5 (silicone) brake fluid. See Purging
the Hydraulic System on page 6-30.
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 Sys-
tem on page 6-29.
Hard pedal –
Excessive pedal pressure is required
to stop the vehicle
Brake fade
Replace the brake shoes. See Brake
Shoe Removal on page 6-9.
Grease or brake fluid on the brake shoe
linings
Replace hub or axle seal and replace the
brake shoes. See Brake Shoe Removal
on page 6-9.
Glazed brake shoe linings
Replace the brake shoes. See Brake
Shoe Removal on page 6-9.
Damaged or distorted brake shoes
Replace the brake shoes. See Brake
Shoe Removal on page 6-9.
Scored or barrel-shaped brake shoe
drums
Replace the brake drums. See Brake
Drum Removal on page 6-7.
Clogged master cylinder lines or hoses
Replace brake lines or hoses as required.
See Hydraulic Line and Hose Replace-
ment on page 6-24.
Frozen master cylinder piston
Replace master cylinder. See Master Cyl-
inder Removal on page 6-28.
Over-aggressive braking
Incorrect or distorted brake shoes
Replace the brake shoes. See Brake
Shoe Removal on page 6-9.
Grease or brake fluid on the brake shoe
linings
Replace hub, axle seal or wheel brake cyl-
inder and replace brake shoes. See
Brake Shoe Removal on page 6-9.
Loose or distorted brake backing plate
Tighten or replace the backing plate and/
or hardware.
Scored or warped brake drums
Replace the brake drums. See Brake
Drum Removal on page 6-7.
Corroded master cylinder bore
Replace master cylinder. See Master Cyl-
inder Removal on page 6-28.
Binding brake pedal linkage
Lubricate and adjust. See Section 5 of
this Maintenance and Service Manual.
Vehicle pulls to one side
Incorrect or distorted brake shoes
Replace the brake shoes. See Brake
Shoe Removal on page 6-9.
Grease or brake fluid on the brake shoe
linings
Replace hub, axle seal or wheel cylinder
and replace the brake shoes. See Brake
Shoe Removal on page 6-9.
Loose or distorted brake cluster backing
plate
Tighten or replace the backing plate and/
or hardware.
Scored or warped brake drums
Replace the brake drums. See Brake
Drum Removal on page 6-7.
Troubleshooting Guide continued on next page...
SYMPTOM
POSSIBLE CAUSE(S)
CORRECTIVE ACTION
