Troubleshooting Your Healey's Brake System

By Norman Nock

Originally published in the Austin-Healey Magazine, February 1998


This chart shows the various problems that can occur with a Healey brake system and their respective solutions. It is extremely important that only qualified mechanics should work on your brakes.


It is also very important that you do not use any silicone-based fluid. I recommend using ONLY Castrol brake fluid. Be sure to change brake fluid per factory service manual.

Symptom

Diagnosis

Action

Fade

Incorrect pads. Overloaded vehicle. Excessive braking. Old hydraulic fluid.

Replace the pads. Decrease vehicle load. Renew hydraulic fluid as necessary.

Spongy Pedal

Air in system. Badly lined pads. Worn inside diameter of cylinder.

Check for air in system and bleed if necessary. Check pads and discs and replace as necessary. Replace cylinder as required. Adjust brakes.

Excessive Travel

Discs running out pushing pads back. Distorted damping shims. Worn linkage.

Check that disc run out does not exceed 0.004 inches (0.0101mm). Check the disc/hub mounting faces. Replace linkage. Adjust brakes.

Brakes Binding

Handbrake incorrectly adjusted. Seals swollen. Seized pistons. Servo faulty (BJ8). Flexible hoses collapsed. Hand cable frozen.

Check and adjust handbrake linkage. Check for seized pistons, repair or replace as necessary. Rebuild booster servo (BJ8). Replace hoses. Replace hand cable.

Hard Pedal/

Poor Braking

Incorrect pads. Glazed pads. Pads wet, greasy or not bedded correctly. Servo unit inoperative (BJ8). Seized pistons. Flexible hoses collapsed

Replace the pads

or, if glazed, lightly rub down with rough sandpaper. Check caliper for damage and repair as necessary. Replace hoses. Rebuild booster servo (BJ8).

Brakes Pulling

Seized pistons. Variation in pads. Unsuitable tires or tire pressure. Worn shock absorbers. Loose brakes. Greasy pads. Faulty discs, suspension or steering. Oil on brake shoes. Flexible hoses collapsed.

Check tire pressure, seized pistons, greasy pads or loose brakes; then check suspension, steering and repair or replace as necessary. Fit new shock absorbers. Replace hoses.

Loss of Fluid

Worn disc pads. External leak. Leak in servo unit (BJ8).

​Check the pads for wear and for hydraulic fluid leakage. Rebuild booster servo (BJ8).

Disc Brake Squeal

Worn rotors. Worn discs. Worn pads.

Renew the retaining pins and discs. Fit new pads.

Uneven or

Excessive Pad

Wear

Disc corroded, rusty Disc badly scored. Incorrect friction pads.

Check the disc for corrosion, or scoring and replace if necessary. Fit new pads with correct friction material.

Dirty Brake Fluid

Hydraulic seals deteriorated.

Rebuild brake hydraulic system.

Not what you were looking for? Don't forget you can check our back issues using the AHCUSA Magazine Index.

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