Q: My car vibrates when I stop. I have the brakes fixed and some months later they vibrate again. My rotors have been machined and replaced several times over the years.
What could the problem be?
A: There are a couple of solutions to your problem that I will explain here. The trouble is that you are not getting to the bottom of the underlined problem.
In recent years new car manufacturers have downsized the size of disc brake rotors mainly to make vehicles more fuel efficient. The downside is that today’s vehicles with the thinner brake rotors are much more vulnerable to brake pedal pulsation.
Here are a few steps to get to the root of the problem.
- The first step in figuring out what is wrong is by removing all four wheels and performing a brake inspection.
- More than likely something is causing the disc brake rotors to run hot, distort and cause brake shutter.
- If you have the choice between machining the rotor or replacing it. Replace it, the theory being if the new rotor distorted the newly now thinner rotor will certainly distort and cause brake vibrations. The average cost to resurface a rotor is one hour labor each, that’s just about $200.00 or more for the job. You may be able to replace the old rotors with new for the same price. We suggest putting the money toward new for a better repair.
Things to check:
- Are the wheels being installed with a torque wrench or a torque limiter to specifications?
- Are the rear brakes working and in adjustment, if not you will overwork the front brakes.
- You can also feel the rim after driving to see if the drums are cold. If they are the rear brakes wether drum or disc with intreagle caliper emergency brake are out of adjustment.
- Prior to retracting calipers spin each wheel, does the wheel spin freely? Is it tight in one area and loose in another as you turn the wheel? In many cases you can indicate what rotors have distorted. Is the same wheel causing the problem each time?
- Look at brake pad wear patterns, are the brakes wearing evenly comparing brake pads right side to left side? If not you may have a restricted brake hose or a brake caliper that is tight or not fully releasing. These conditions will cause brakes to run hot distorting the steel rotor resulting in vibration on stops.
- If you are absolutely convinced that all is well with the brake system and are still experiencing the problem it is time to replace the rotors one last time, but here's the trick.
We have had many customers that have had to constantly service or replace their rotors during the new car warranty period only to be frustrated in never having the problem resolved. How do we fix it once and for all? Very simple, throw out the original equipment rotors and replace them with a top of the line hardened steel or high performance rotor. These parts are only available in the aftermarket and are not available at your new car dealer. In these cases vehicles are driven hard under sever conditions or under heavy commercial use causing rotors to run very hot. Original equipment disc brake rotors simply do not perform well under these extreme conditions.
You may also comment on this post by contacting Bill Pelletier, President, Brake Centers of America at BrakesUSA@aol.com or www.BrakeCenters.com Brake Centers of America serves customers in Westchester County, New York and in Southern Connecticut.