Initial Inspection and Diagnostic Overview
PRELIMINARY CHECKSIf primary piston cups are swollen, then rubber parts have deteriorated. This deterioration may also be evidenced by swollen wheel cylinder piston cups on the drum brake wheel cylinders or the master cylinder cover diaphragm. If deterioration of rubber is evident, disassemble all hydraulic parts and wash with alcohol. Dry these parts with unlubricated compressed air before assembly to keep alcohol out of the system. Replace all rubber parts in the system, including hoses. Also, when working on the brake mechanisms, check for fluid on the brake linings. If any fluid is found, replace the linings. If master cylinder piston seals are satisfactory, check for leakage or excessive heat conditions. If condition is not found, drain fluid, flush with brake fluid, refill and bleed the system.
Tires - Tires having unequal contact and grip on road will cause unequal braking. Tires must be equally inflated, identical in size, and the tread pattern of right and left tires must be approximately equal.
Vehicle Loading - A heavily loaded vehicle requires more braking effort. When a vehicle has unequal loading, the most heavily loaded wheels require more braking power than others.
Wheel Alignment - Misalignment of the wheels, particularly in regard to excessive camber and caster, will cause the brakes to pull to one side.
Trailer Towing - Towing a trailer requires longer braking distances and tends to overheat the brakes sooner.