Chevy Blazer Brake Problems

The Chevrolet Blazer is a truck-based SUV that was manufactured from 1967 to 2005 in several model types, mostly with front disc and rear drum hydraulic brakes. Some early models had four wheel drums, and some later models had four wheel disc braking systems, all of which could develop problems due to normal wear. The average backyard mechanic can diagnose most Blazer brake problems in about 20 minutes.

History

Determine the type of braking system on the Blazer. From 1967 to the mid-1970s, the full-sized Blazer K-5 had four wheel drum brakes with front disk systems as an option. These drum systems were prone to reduced performance in adverse conditions such as rain or dust due to inherent design, and the stopping power was increased significantly with the move to four wheel disc systems on S-models after 1996. All models use a master cylinder to pump hydraulic fluid to the brakes. Any wear or deficiency at points in this system could cause problems, readily identified by several key sounds or observations.

Sounds

Listen for sounds while the brakes are in operation. The most common wear for most systems are the shoes or pads, which are designed to make a high-pitched squealing sound when they are reaching the end of their lifespan. Other issues can be determined by sound, such as brake "dragging" or broken parts, which can manifest as clunking or scraping sounds when the pedal is depressed.

Leaking

Check all lines, calipers, wheel cylinders, and master cylinder for leaking fluid. A loss of fluid could cause the system to show reduced performance, or quit working entirely, and should be corrected immediately. The master cylinder, located under the hood in front of the driver, is where the mechanic can add fluid through the top cap opening. This cylinder contains several pressurized membranes to regulate fluid pressure, and the failure of any of these rubber gaskets can cause leaking or reduced stopping power. Connection fittings, where the lines connect to each other or to the braking components, can also be prone to leaking. All Blazers for all years use DOT-3 braking fluid.

Vibration

Check the disk brake system for vibration when in operation, if applicable. Vibration, or pulling to one side during braking is a clear indicator of "warped" rotors. The rotor, a flat surface that is pinched by the pads, can become uneven due to heat. This uneven surface becomes vibration when the warped rotor runs over the pads like a bent vinyl record on a turntable. The proper repair for this problem is complete replacement of the rotor, as the defect cannot typically be fixed by turning or machining.

Calipers and Wheel Cylinders

Check key braking system components, such as the wheel cylinders and calipers, for proper function and leaks. These parts are the primary braking mechanisms for stopping the truck, where the fluid causes the hardware to press or squeeze the parts together, making friction and stopping the vehicle. If these components fail, then the entire system is compromised.