Auto Repair Help
JIM’S CORNER – AUTO REPAIR HELP

DIAGNOSE – CAR PULLS WHEN I STEP ON THE BRAKES
by Jim Miller

SYMPTOM SUMMARY
The vehicle pulls to the right or left when the brakes are applied.

USUAL CAUSE
The usual cause of this symptom is contamination on the braking surface or a malfunctioning caliper. It can also be caused by different tire sizes on the right and left wheels. Worn suspension components can also cause this symptom.

DIAGNOSIScheckengine
If contamination, such as grease or oil is present on the left side, the vehicle will pull to the right since the left side will not provide the same braking force as the right. A visual inspection is the first step in diagnosing the problem. Perform a visual inspection on both sides of the vehicle. Check the following:

1. Inspect the tires for even tread wear and overall condition. Check to ensure tire inflation is the same and to specifications.

2. Inspect the brake rotors for contamination. On front wheel drive vehicles, inspect the CV boots for tears. If torn, the CV boot can allow the grease to contact the brake rotors.

3. Check the brake pads to ensure they are worn evenly on both sides of the vehicle. If one side is worn excessively, it could be caused by a sticking brake caliper. The brake caliper can slide or the pistons can stick, causing the brake caliper to maintain braking force on the caliper. This might be accompanied by a discolored brake rotor as well. Rotation of the wheels by hand with the vehicle on jackstands should be even on each side. On front wheel drive vehicles, the transmission should be placed in neutral. Ensure the emergency brake is engaged and proper jacking procedures are used. A wheel that requires excessive force to rotate by hand should be investigated further.

4. Inspect the rubber brake hoses that connect to the calipers. A collapsed brake line can expand under pressure, allowing the brake fluid to enter the caliper then collapse trapping the brake fluid in the caliper.

5. With the vehicle jacked up and the tires on, inspect the front end components for excessive wear. With one hand on the front of the tire and one on the wheel, try to turn the wheel right and left (as if in a turn, not rotational). The wheel may be able to be turned to the right or left, but it should be tight and have no free play back and forth. Perform the same test with one hand on the top and one on the bottom of the tire. With your hand on the top, pull out while pushing in with the hand on the bottom. Then do the opposite, pull out on the bottom and in on the top. There should be no play in the wheel. If play is present in both of the above tests, it is usually an indication of a worn wheel bearing. If there is only play from right to left, it is usually an indication of a worn suspension component such as a tie rod end or rack and pinion. Perfoming the test while inspecting the front end will usually reveal the worn component.

PRECAUTIONS, TIPS, and NOTES
Brake rotors become extremely hot during braking. Use caution when working on the brakes shortly after vehicle operation. Always refer to manufacturers jacking procedures to prevent damage to the vehicle or injury to yourself.

(Jim is a lifelong fan of Dodger Baseball and used to race sprint cars in the 1980s.)

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One Response to “My Car Pulls When Braking”

  1. maria says:

    very helpful and indeed truth on what was done at least on my car. thanks for sharing :)

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