Pulling Right Under Braking - Brake Test Results

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Mar 10, 2017
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Our Mini pulls right under hard braking.

Back in July it had brake testing as part of its annual testing. These were the results...

Brake Test Results.jpg


Both right hand side brakes appear to be working harder than the left. 19% imbalance with a bias to the right up front and 30% with a bias to the right at the back.

Is this enough to cause pulling under braking? It's not horrific and only happens under very hard braking. I can lock up both front wheels, if that means anything.

There is a small amount of play in the upper ball joint on the N/S and slight play in the wheel bearing on the O/S. Both issues will be rectified over the winter months.

I'm just unsure if I should be servicing the brakes or looking for another issue?
 
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30% would be a fail here.

But play in the suspension could change the toe and add to the brake imbalance. Also does it happen with 2 occupants aswell?
 

Bailes1992

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30% would be a fail here.

But play in the suspension could change the toe and add to the brake imbalance. Also does it happen with 2 occupants aswell?

No idea on of the occupants change it.

Just had a read and apparently anything more than 30% is considered a fail here.

What's interesting is that it originally failed as the rear brakes were recording little to no effort, they replaced the rear shoes and still we have a 30% imbalance. Seems like a poor job was done replacing the rear brakes, that or they need some adjustment.

I think I'll strip and replace/rebuild the entire braking system over Christmas. For peace of mind more than anything.
 
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the drums need cleaning up if the old brakes hadn't worked for a while.

But this being a light car, any weight imbalance seems to amplify brake imbalances. The heavier loaded side can deal with higher brake pressures, and on a 2000lb car 100 lb more on one side does have an impact on heavy braking, not on light to moderate braking though.
 
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pulling under braking bothers me, regardless if it's legal. I don't want to fight the steering wheel under any circumstance really, but definitely isn't needed when braking.
 
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Done thousands myself when I worked at a dealership. it can show up some stuff safer than taking it on the road and finding out that way. But a pass doesn't mean the brakes are 100%, especially sliding calipers are great at hiding defects such as stuck sliders and stuck pads.
 
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