'Clunk' from rear brakes on MCS

[Krispi]

I've been searching through the forums for a description of a small problem I have noted with my '03 MCS, but haven't found anyone else with the same issue:

When I brake from moving slowly (still in 1st gear) there is an audible 'clunk' from the rear of the car, possibly the rear brakes themselves. There is no problem with the car slowing down. I only notice this when braking from moving slowly, although it may simply be that at higher speeds I can't hear the noise when I first apply the brakes.

I'm aware of the ABS test the car does at 12MPH along with the auto-central locking, but this noise is occurring when I slow down rather than accelerate.

Anyone else with a similar issue, or might know what is causing it?

As it's not causing any problems, I was just going to mention it to the garage when it has it's first service, but I don't want to make a big issue about it if it isn't really a fault.

[Steeljacket]

Not sure what it is but took my MCS into dealers today to have gear shift cables replaced dur to vibration and noticed on the service sheet that it was down to have something done on the rear brakes but I don't know what and have not complained about anything on the rear brakes - could this be a minor recall issue for the MCS rear brakes??

I will ask them tomorrow when I collect it and will let you know

[Polmear]

How loud is the noise? Can you tell if it is coming from one side or the other?
You may want to try bouncing the rear corners while the car is stopped, to see if it is something loose that moves when the suspension travels. You may also want to pull off the wheels to look at the 2 caliper assemblies, possibly some shim fell off of one (or broke off), but if one looks like it has a piece that the other doesn't...
Good luck in your diagnosis, keep us informed as to the cause if you ever find out.

[Krispi]

The noise is about as loud as the ABS check done at 12MPH. It's more noticeable with the windows wound down. There is actually a similar noise from both sides of the back of the car (which is why I suspect the breaks), oddly enough each side doesn't 'sound' at the same time, I'll usually hear a clunk from one side first then a second later from the other.

I'll try having a look around the back of the car this weekend and see if I can spot anything obvious, thanks for your suggestions.

[Mega Mini]

I had this problem on a p reg fiesta. It was a tap that could be heard at slow speed in both forward and reverse. My garage changed the shoes under warrenty and this would solve the problem for about a week when it would come back. eventually they changed them agin and the problem stopped. My noise was from the front passenger side. I think it was due to poor fitting rather than a design fault. when are you shoes next due a change?

[robbo21]

I collected my cooper s on the 1st of september 03. After the first couple of days i noticed a matalic knocking noise coming from the back of the car at different speeds, anyway i took it back to my dealer and it turns out that it was the boot catch that was making the noise. They also said that if i had any more problems that i should also try the two rubber grommets on the boot door itself. As these can be wound in and out to adjust how the boot closes.
Might be worth a check if you cant pinpoint the noise.

[davidac]

My wife has this problem on her Audi right now. I had it once before on my car. I think it is just the calipers sticking. They get all gunked up with brake dust and can stick. The clunk is the caliper braking free after being stuck for a moment. That is why you only hear it at low speeds when slowing gently. Aggresive braking from moderate to high speeds you will not hear this. A good way to eleviate this problem is get out and do some hard braking from good speed which will scrub off the buildup.

[EBMCS03]

Quote: Originally Posted by davidac

My wife has this problem on her Audi right now. I had it once before on my car. I think it is just the calipers sticking. They get all gunked up with brake dust and can stick. The clunk is the caliper braking free after being stuck for a moment. That is why you only hear it at low speeds when slowing gently. Aggresive braking from moderate to high speeds you will not hear this. A good way to eleviate this problem is get out and do some hard braking from good speed which will scrub off the buildup.

Yes I also suspect that its that too. I have it on my camry once in a while and I think I've heard it once in my MINI so far.

[Krispi]

Quote: Originally Posted by davidac

My wife has this problem on her Audi right now. I had it once before on my car. I think it is just the calipers sticking. They get all gunked up with brake dust and can stick. The clunk is the caliper braking free after being stuck for a moment. That is why you only hear it at low speeds when slowing gently. Aggresive braking from moderate to high speeds you will not hear this. A good way to eleviate this problem is get out and do some hard braking from good speed which will scrub off the buildup.

I now think that this is the most probable cause of the noise I am hearing. I can't see any obvious problems at the back of the car (although I'm hardly a trained mechanic). The car doesn't do a great deal of miles, currently I've done 2400 and the car is 7 months old. The low use may also be contributing to the calipers sticking. I'll try a bit more hard breaking and see if this helps. If it is still continues to be a problem I'll mention it at the cars first service.