brake imbalance

[mr lobitos 0]

took vr for mot today,failed on brake imbalance on front and rear brake application uneven.Pretty chuffed :clap: ,no advisory items either.where do i start looking with brakes, advice please

[Jim 2]

That could be the brake bias compensator valve thingy? Have you lowered the car since you last got the MOT done?

[Abdul 0]

That could be the brake bias compensator valve thingy? Have you lowered the car since you last got the MOT done?

 

Most likely the bias valve... Mine was rusted shut on my valver... car used to brake hard from the arse end making high speed braking very scary!!

 

It can also be due to suspension changes as Jim's mentioned. Either way you can most likely adjust it and free it up if its stuck and if not im sure they're pretty cheap.

[volksworld13 0]

usually inbalance is worn discs warped causing an inbalance on the opposed wheels, do you have brake judder when braking felt through the pedal,the bias valve will most likely be seized as mentioned,lubricate it,and work up and down.

[mr lobitos 0]

car has been lowered since last mot,will give everything a good clean and look at valve thingy,cheers for the input,let you know(by the way what does the valve thingy look like and its place on car )

[markrtw 0]

Underneith, just in front of the rear axel on the passenger side. It's quite obvious as there are several brake pipes going into/coming out of it.

[Jim 2]

Yeah - not quite sure on the procedure to reset it, but basically the compensator is attached via a spring to the rear axle. The idea being that depending on how loaded the car is or how heavily the car is pitching forward under braking, the compensator will apply more or less braking force to the rear. As you can imagine, as it's height dependent, after lowering the car it messes up how it works.

 

Have a search - I'm sure it'll have been discussed before :)

 

*edit*

 

Touched on by Toad here:

 

viewtopic.php?f=23&t=75137&hilit=brake+compensator+adjust&start=15

[RW1 0]

Toads method is porbably OK. The correct way to go about it is here.... Setting the brake compensator

 

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[Supercharged 2]

usually inbalance is worn discs warped causing an inbalance on the opposed wheels, do you have brake judder when braking felt through the pedal,the bias valve will most likely be seized as mentioned,lubricate it,and work up and down.

 

Side to side imbalance would not fail an MOT though believe it or not (as long as the calipers are working to a specific value)

 

This will be an imbalance front to back and as you say, the problem will be at the rear and most likely the compensator.