NOTE: Master cylinder installation must allow the shaft to completely extend (retract) when no load is applied. Failure to do so can result in many of the following problems.
| Trouble | Probable Cause | Correction |
|---|---|---|
| 1. Unable to obtain sufficient hydraulic brake pressure or spongy pedal | Air in hydraulic system Brake pedal binding |
Check for source, then bleed hydraulic system Check for freedom of movement of brake pedal and master cylinder |
| 2. Excessive pedal travel | Incorrect installation Leak in system—brake, master cylinder, fittings, or lines Defective master cylinder Back plate bolts loose |
Refer to Installation Instructions Locate leak and repair Repair or replace master cylinder Torque bolts to proper value |
| 3. Brake drag | Piston jammed in caliper Foreign matter wedged in brakes Master cylinder not releasing hydraulic pressure Parking brake valve defective Foreign matter lodged between torque pins and torque plate bushings Bent torque plate Bent torque pins |
Remove caliper and repair cylinder or piston Locate and remove foreign matter Repair or replace master cylinder Repair or replace parking brake valve Clean and inspect — replace if necessary Replace torque plate Replace torque pins |
| 4. Rapid disc and/or pad wear | Dragging brakes Excessive rusting, scoring, or pitting of brake disc Excessive back plate deflection caused by bent bolts or over-torquing of bolts |
Refer to Trouble #2 Clean or replace disc Check torque of bolts and replace bolts if bent |
| 5. Brakes won’t hold | Improper conditioning of brake pads Contaminated pads Insufficient hydraulic pressure Brake pad carburized (overheated) |
Condition pads per Installation Instructions Replace pads Refer to Trouble #1 Replace pads |