Checking your brakes at regular intervals is a good practice towards the maintenance of your Chevy. Even with proper maintenance, you may find yourself with an unexpected brake problem -- here are some of the most common examples.
Low Brake Fluid: Your Chevy may develop a leak in the system that will result in the fluid level going down. It can also be the result in worn disc brake pads. If you see the Brake Warning Light illuminated, it is probably a leak. Although, if you have a fluid level sensor in the master cylinder reservoir, you may see this light come on when the fluids are low. Brake failure is common if the fluid leaks out of the system. If you determine that you have a leak, check the calipers, hoses, lines, master cylinder and wheel cylinders for the leak. Replace the defective part.
Low Brake Pedal: This can occur if the rear drum brake shoe adjusters happen to be rusted or sticking. They are not compensating for normal lining wear. You should clean or replace the adjusters to eliminate the problem. If you try to fix it by adjusting the rear drum brakes, you will still have the problem until you fix the adjusters. A low brake pedal can also be due to a fluid leak or worn brake linings.
Soft or Spongy Brake Pedal: Too much air in the system due to improper bleeding is usually the cause of this problem. However, it can also be due to fluid loss or a low fluid level. Bleed the brake lines as recommended by Chevy to fix this. You could also have a ballooning brake hose when the brakes are applied. Check your brake hoses for anomalies.
Excessive Brake Travel: If the brake linings are worn, the drum brakes are misadjusted or the brake lines have air in them, you will have this issue. You may lose your brakes if you run out of travel before they are fully applied. You can pump the brakes before application to help offset this problem, but you need to get it fixed.
Sinking Pedal: You may notice this while sitting at a stop light. A slow descent of the brake pedal means that the pressure is leaking out of the master cylinder. The brakes can fail if your hydraulic system or master cylinder is leaking.
Pulsation: This is the symptom of a brake rotor that has warped. It will need replacement or resurfacing. A rotor face must be within .0005 inch of being parallel and flat with no more than .003 inch of runout. This can be repaired by resurfacing or shims. If it is too worn, you must replace it.
Scraping Brakes: Metal-to-metal sounds mean that the pads or shoes are worn out. They need to be replaced at once. You may also need to have the drum or the rotors replaced or resurfaced because you waited too long to change the shoes and pads.
Brake Squeal: A vibration between the pads and the calipers or the pads and the rotors can cause them to squeal. A brake pad that is semi-metallic will be noisier than a non-asbestos or ceramic pad. You should put new pads on your Chevy and replace or repair the rotors. You could add shims, use a brake noise aerosol, or brake grease to the backs of the pads to dampen the noise.
Brake Chatter: Warped or improperly finished rotors will cause this noise.
Brakes that Grab: If there is oil, brake fluid or grease on the pads, they will slip and then grab hold. You may feel your Chevy jerk when you brake. Check your pads for any type of contamination. Replace them if you see that they have oil, fluid or grease on them. Check out the system to make sure that you do not have a caliper leak or an oil leak. A drum or rotor that has deep scores in it will cause the brakes to grab. They will need to be resurfaced.
Brakes that Drag: Dragging brakes cause the brakes to wear out faster, and they can cause steering pull and tire wear. They can also cause you to use more fuel. The common cause of this is a broken or weak retracting spring on drum brakes, corroded or jammed caliper piston, corroded mounting pins or the bushings on a floating caliper, the drum brake self-adjusters are overextended or there is an emergency brake cable that is sticking or is frozen in place.
Brake Pull: Uneven braking means that you have one front brake on your Chevy that is not operating properly. Your brakes pull to the good side. This can be due to oil, grease or fluid on a pad, a caliper that is stuck, brake line blockage, or wheel bearings that are loose.
Hard Pedal: You may have a loss of power assist because the engine vacuum is low. It can also be a vacuum hose leak to the booster, or it can be a booster that is defective. You will find the booster between the master cylinder and the firewall in your engine compartment. A check valve that is faulty can also let vacuum bleed out. You can diagnose this by starting your Chevy in order to build vacuum, and then turning it off for four or five minutes. Then you should try the brakes. If you get no assist, you need a new check valve.
Other Issues and Fixes
- The vacuum booster can be checked by pumping the pedal a few times while the engine is off. That bleeds out any vacuum. Next, hold your foot to the pedal while starting the engine. A properly working booster will make it easier to hold the pedal and may even slightly depress the pedal by itself. If nothing happens, check the vacuum connections, and if they are okay, you need a new booster and vacuum hose.
- A hydroboost power brake vehicle with a hard pedal can be the result of a belt that is loose on the power steering pump, fluid levels are low, power hoses leak or there are valves with leaks or faults on the hydroboost unit. Replace the hydrobooster.
- On ABS vehicles, the ABS pump or the high-pressure accumulator can be the cause of power loss. The ABS warning light usually comes on when there is this type of problem. It will also have a fault code related to the loss of boost. You need a scan tool to read the code.
While these are the most common causes of brake issues on your Chevy, you should never allow your brakes to go bad. At the first sign of trouble with your brakes, you need to either fix them or seek help from a certified GM mechanic. Always replace components with genuine GM parts to avoid premature failure of brake system components.