GM Full-Size Trucks 1970-1979 Repair Guide

General Information


All Chevrolet and GMC trucks from 1970 are equipped with a split hydraulic braking system. The system is designed with separate systems for the front and rear brakes using a dual master cylinder with separate reservoirs. If a wheel cylinder or brake line should fail in either the front or the rear system, the truck can still be stopped with reasonable control.

In 1970, trucks were equipped with front and rear drum brakes. The front brakes are duo-servo anchor pin type which are self-adjusting. The rear brakes are of the same basic type.

Beginning in 1971, trucks were equipped with disc brakes at the front and drum brakes at the rear. The drum brakes are still of the duo-servo anchor pin self-adjusting type, while the front disc brakes are single piston sliding caliper types. The front disc brakes are self-adjusting.

The parking brake is either hand or foot operated, but in any event, acts upon the rear service brakes.