When you apply the brakes while driving, the brake system should slow and stop straight and true. If you are experiencing any pull from your vehicle while braking, it could be any number of things that are causing the problem. Here are the usual suspects that lead to brake pull.
Common Issues Causing Brakes to Pull
Sticking Calipers–When the calipers are not evenly applying pressure due to dirty slides, then can stick a bit before actuating. This means that they’ll press the pads into the rotor more slowly than the calipers on the opposite side of the car, thus causing the car to turn or “pull” to one side a bit.
The calipers need to be removed and the slides need to be cleaned.
Do not allow your calipers to dangle from the brake hose when you remove them.
Clean the caliper and the mounting surface with sandpaper to remove rust and dirt.
Lubricate with a bit of disc brake bearing grease, then reattach.
Make sure you do not get grease on any other part of the brakes.
Delayed Piston–The piston seals allow the caliper to engage and disengage. If the piston seals are old, worn or damaged, the caliper may stick.
Replace the pistons and rebuild the calipers.
Contamination–There can be contamination on the brake pads from oil, water, grease and other materials that stop the pads from solidly connecting to the rotor.
In many cases, this contamination can be permanent, so it is advisable to replace the pads.
Unequal Fluid Pressure–In some cases, there may be a hose blockage or other part that is interfering with the pressure in the brake fluid.
The quickest way to determine if this is your problem is to measure the temperature of the hub with a non-contact infrared thermometer. The temperature on the wheel will be higher than the other wheel on that axle. From here, the blockage will need to be cleared.
Master Cylinder Leak–In some cases, the loss of fluid in the master cylinder can cause the brake on that wheel to stop working. Check the wheel for leaks and replace the master cylinder or hose that is leaking. If it is your master cylinder, your pedal will be soft.
Identify the source of the leak and replace or seal the damaged parts.
Wheel bearings–Loose wheel bearings can cause the vehicle to pull when the brakes are applied.
If you find your vehicle starting to pull while driving, you may need to replace the bearing.
Warped rotor–A rotor that has been warped due to overheating or overuse can cause the brakes to become unevenly applied. The pads cannot make a good connection on a warped surface.
Replace the rotor or machine it down to a smooth surface.
NOTE: A “warped” rotor isn’t actually warped. It’s just that the surface has become degraded enough to require resurfacing. Still, most shops and technicians use the term “warped rotor” to describe a rotor than needs to be resurfaced.
Brake lines–Sometimes air can get into brake lines, causing the brake system to lack complete function.
If this is the case, you need to bleed the brakes to remove the air.
Alignment and Tire Pressure–These two things can commonly cause the car to pull.
It is easy to check your tire pressure for proper inflation, but checking your vehicle for proper alignment requires the car to go to the shop. However, you can approximate an alignment test on your own following this procedure.
Do I really Need to Fix Brakes that Pull?
In a word, yes. No matter what is causing the brakes to pull, you need to take care of the problem immediately, as pulling brakes can quickly lead to non-functioning brakes without repair.