Leaking brake pipe, hose, or connection.

Refer to Brake Pipe Replacement .

Leaking piston seal.

Refer to Brake Caliper Overhaul .

Leaking master cylinder.

Refer to Brake Fluid Leak .

Air in the brake system.

Refer to Hydraulic Brake System Bleeding .

Contaminated or improper brake fluid.

Refer to Brake Fluid and Brake Fluid Handling .

Worn-out brake lining. Replace the linings.

Refer to Brake Pad Inspection .

Uneven lining wear. Replace the lining or correct the condition.

Refer to Brake Pad Inspection .

Park brake switch circuit grounded.

Refer to Park Brake.

Parking brake not releasing.

Refer to Park Brake.