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How to Troubleshoot a Car that Pulls to One Side under Braking

When it comes to driving safety, you need things to be very predictable and especially when you're driving your vehicle at speed. You want to ensure that it behaves the same way each time you put your foot on the brakes, to keep you and your family as safe as possible. If you're unsure about your brakes, how can you troubleshoot the issue so that you can get back to normal as quickly as possible?

Understand the Brake System

It pays to understand how your car's braking system works. Each wheel has a brake disc and calliper set-up mounted to the hub and within each calliper is a pair of friction pads. When you press the brake pedal this will activate the system and push hydraulic fluid to each wheel, forcing the brake pads into contact with the rotary disc and bringing the associated road wheel to a halt.

Look for Strange Behaviours

You've noticed, however, that the vehicle will pull to one side whenever you hit the pedal or may even continue to slow down even when you take your foot off the brakes. This sounds like an issue with the brake callipers and they seem to be operating erratically and staying engaged when they should not be.

Inside the calliper, there is a piston and valve, designed to move into the "on" or "off" position in order to push the brake pads forward and let them return. These pads will sit a millimetre or so away from the disc when not engaged and do not have far to travel in order to decelerate the disc.


In your case, it's possible that something has become stuck in between the piston and the pad, or in between the disc and the pad. This debris might have been picked up from the road or could be part of the protective rubber boot which surrounds the mechanism. When this boot begins to perish, pieces of rubber can come loose, and dirt can access the area. Typically, this will only happen on one side of the vehicle at any one time and this explains why the vehicle will pull to one side of the road upon deceleration. Likewise, dirt can keep the piston in the "on" position and not allow the brake pad to release the disc. This would explain why the car continues to decelerate, even though you have taken your foot off the pedal.

What to Do Next

Armed with this information, get in touch with your mechanic as soon as possible. They will be able to use the right professional tools to clean and reset your braking system and get you back towards normality. Or, they can perform the necessary car repairs so you can confidently drive once more.