Problem with the rear brakes, maybe?

**Steve Webb** · 08-09-06, 12:13

Before I start stripping the rear brakes, I thought I'd ask if anyone else has similar problems with the rears. I'm running uprated disks and pads, and have removed some of the trim/weight from the rear of the car. As a result it sits a little higher at the rear which has affected the rear brake compensator. Because of the uprated pads/disks I never seem to need much brake pressure and the rear pads only seem to make contact with the disks over a small area. I've got unswept areas both close to the hub and at the edge of the disk. I've taken the pads out to look at them and they look brand new, even though they have been on the car for at least 2 years.
Anyone else got a similar sort of wear pattern?

Juan AR155Q4 · 08-09-06, 15:11

I´d re-calibrate the compensation valve. Your rear brakes aren´t working as they should. You´ll have to notice a big change if you do this.

Brul(tm) · 08-09-06, 17:17

I also have uprated discs and pads, butt didn't change anything else.
The pads and discs show clearly the signs of usage and look anything butt new or unused.

Greetings,
Marc

**Steve Webb** · 08-09-06, 17:52

Looks like i'll be fiddling with the valve then to fool it into thinking the rear suspension is more compressed than it really is.
Never ends does it!

Brul(tm) · 08-09-06, 19:43

Originally Posted by Steve Webb

Never ends does it!

When does the hurting stop

Last Thursday when I drove to work, the left front tire decided to torn apart. So tomorrow I am getting four new tires.

I also had a problem with the rear brakes a view years ago. The problem I had was with the brake compensator. Maybe you should take a look at this part?

Greetings,
Marc

FletchQ4 · 08-09-06, 22:24

Im sure there is a spring involved that needs to be shortend when your car is lowered, if i can remember lots of cars have this spring missing.

Brul(tm) · 08-09-06, 23:26

Originally Posted by FletchQ4

Im sure there is a spring involved that needs to be shortend when your car is lowered

I can assure you that this is not the case! My car is 50mm lowered and I didn’t change anything at this point.

I’m convinced that most of the problems with the rear brakes are related to the brake compensator en probably the missing spring or one that can’t move anymore (the mechanical arm). I once mist the spring from the brake compensator and the rear brakes didn’t do anything at that moment.

Greetings,
Marc

**Steve Webb** · 12-09-06, 12:48

Bugger, bugger, bugger.
Just been under the car to try and sort out the rear brakes, looks like the compensator was seized and the spring wasn't adjusted correctly.

Just to clarify things, the 'spring' goes between the rear brake compensator and the rear ARB. If you lower your car, you will need to adjust the spring fixing at the ARB end otherwise the compensator will permanently think the rear of the car is weighted down and will allow more pressure to the rear brakes.

Anyway, i freed up the compensator with loads of WD40 and a Birmingham screwdriver, (Lump hammer) and reset the spring. Went out for a test drive and its only gone and blew a hole in one of the rear brake pipes.

Added to that I burn't my back on the exhaust pipe.

Back under there this afternoon to see if i can spot where the brake pipes have split.

Anything special I should know about bleeding the brakes?

**AlfaJack** · 13-09-06, 14:22

Bleeding brakes isnt hard, just need to get wifey to sit in the car and shout commands at her to push peddle up and down - I would replace both sides though

**Steve Webb** · 14-09-06, 10:56

From looking at the state of the 4 pipes attached to the brake compensator, I'm going to replace all the brake pipes at the rear of the car. They have all got fairly serious corrosion around the unions. I'm going to take the car down to a local garage to get it done though. All very inaccessible when the car is only on ramps.

On the plus side though, the rear disks were cleaning up well before the pipe went!

markgq4 · 15-09-06, 22:41

no no no you should do it yourself.... theres nothing better than pooring brake fluid all over yourself as well as filling eyes with all the bits of debris which fall of when your under there. !

(my P4 did the same trick week ago.)

**AlfaJack** · 18-09-06, 10:38

Originally Posted by Steve Webb

Bugger, bugger, bugger.
Just been under the car to try and sort out the rear brakes, looks like the compensator was seized and the spring wasn't adjusted correctly.

Just to clarify things, the 'spring' goes between the rear brake compensator and the rear ARB. If you lower your car, you will need to adjust the spring fixing at the ARB end otherwise the compensator will permanently think the rear of the car is weighted down and will allow more pressure to the rear brakes.

Anyway, i freed up the compensator with loads of WD40 and a Birmingham screwdriver, (Lump hammer) and reset the spring.

Steve, I checked my compenstor out yesterday and it looks pretty bad, i touched the spring and it just sprung off, not sure if it was conected properly before or not,

the compensator itsself is completely siezed, no movement and looks rusty, i got a pic but not a very good one.

How much should it move ? a lot or just a few mm's?

Whats the best way to free it? not too much space under there!

**Steve Webb** · 18-09-06, 20:09

Sounds like the spring was either buggered or not correctly adjusted at the ARB end of things.
The compensator doesn't really move at all, so its pretty tricky to spot if its working from underneath. I gave mine a good soaking in WD40 then used 2 extension bars from a socket set, and a trolley jack to apply pressure to it.

Make sure you pull the rubber boot off of the compensator and give it a good spray inside with WD40.

**AlfaJack** · 18-09-06, 22:23

Originally Posted by Steve Webb

Sounds like the spring was either buggered or not correctly adjusted at the ARB end of things.
The compensator doesn't really move at all, so its pretty tricky to spot if its working from underneath. I gave mine a good soaking in WD40 then used 2 extension bars from a socket set, and a trolley jack to apply pressure to it.

Make sure you pull the rubber boot off of the compensator and give it a good spray inside with WD40.

Cheers Steve

**AlfaJack** · 23-09-06, 12:10

Sorted now but not been for a drive,

It makes a massive difference as to whether the wheels are off the ground or not, I put it on a ramp to fit it properly, the spring is now taught.

This rusty powder was inside that boot, Iv not covered it in WD40