OK, what do you do when you apply your brakes and there is minimal resistance resulting in the brake being depressed all the way to the floor? First, you read this, then you call Freeman Grapevine, you could have a very serious issue.
The best way I can explain brake problems is to quote some expert advice. My guys in the Freeman Service department know this stuff like the back of their hand. They can diagnose a brake issue almost as quickly as it takes to pull into the service bay. My guys are really busy, so I pulled to following information for 2carpros.com. It is a well rounded description of common…and not so common…braking issues. Thanks for the info guy!
Check the Brake System Fluid Level – Check the level of fluid in the brake master cylinder. It is natural for fluid to be a low if the front or rear brake pads-shoes have worn down, but if they are in good condition and the brake master cylinder reservoir is empty you might have a brake fluid leak somewhere in the system. Inspect front brake calipers, rear wheel cylinders (drums) or rear brake calipers and flex hoses front and rear of vehicle and look for any sign of fluid leakage.
Also check the rear of the brake master cylinder for fluid leaks, if brake fluid is present the master cylinder seals have failed and the master cylinder needs to be replaced. Replace any parts that are leaking or show signs of previous leakage. Refill and bleed the brake system as needed. (Note: if brake fluid has contacted the brake components i.e. brake pads or brake shoes the brake lining material is contaminated and must be replaced) If the brake fluid in the reservoir is full proceed to the next step.
Brake Master Cylinder is Full of Brake Fluid – If upon inspection the brake master cylinder is full of fluid, the brake master cylinder may be bypassing internally. This means the seals inside the master cylinder have failed allowing the fluid from the front of the master cylinder plunger to slip through to the rear of the plunger and back into the fluid reservoir. Allowing the brake pedal to go to the floor with out pressurizing brake fluid into the system. Replace master cylinder with new unit and bleed system as needed.
Failing Axle Bearings – The vehicle axle bearing holds the wheel true to the axle shaft while allowing the wheel to rotate. If the bearing fails it will allow the rotor to move back and forth, forcing the brake pads inward into the caliper. Then as you apply the brake pedal it will go to the floor as the caliper fills with fluid. In this case it may take one or two pumps to the brake pedal to regain normal operation. Inspect and replace failed axle bearings as needed, finish by bleeding and adjusting the system.
Air in Brake System – When brake calipers or rear wheel cylinders fail they can allow air into the system when the brake pedal is released. Bleed the brake system by loosening the air bleeder, if air is observed from the bleeder replace the caliper or wheel cylinder and re-bleed system. This condition is rare but it does happen.
If you believe that you are experiencing any of these problems, bring your Buick, or GMC into Freeman Grapevine immediately so we can take a look at it. The last thing you what while cruising at 60mph on the highway is to encounter a brake failure.