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