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        General >> Problems >> Clunking front brakes
        
(Message started by: Jonnycab on Jan 17^th, 2010, 2:00am)

Title: Clunking front brakes
Post by Jonnycab on Jan 17^th, 2010, 2:00am

It all started about 8 months ago when I fitted new discs & pads. Everything was normal & fine for a couple of months :)

Then one day, when it was raining, I noticed a clunk from the front brakes when nearing to a stop. It was a clunk I've never heard before, coming from the front (kind of metal on metal). Checked the wishbone bushes & ball joints, drop links, anti roll bar bushes & track rod ends & there was nothing wrong there....."It's gotta be a brake problem" I thought.

I cleaned up the calipers, spread lithium brake grease on the sliding pins & re-copper greased the pads & it was fine for a few months, come rain or shine :)

Then it started again....a big single 'metal on metal' clunk when nearing to a stop, coming from the front brakes ???....Mainly from the near side, but also doing it (not as loud) from the off side.

Thinking that maybe the 'TRW' pads were possibly badly made & knocking against the the top of the pad carriers, I decided to purchase a different make of pad..'Quinten Hazell'. They were fine for a few months, but then started to do the same again.

So I pulled the pads out, cleaned them & the calipers, re-copper greased the pads etc & they have been fine....until a few days ago, when they started clunking again when coming to a stop >:(

Can anyone explain this phenomenon ?
.
.
There are two things that I can think of as being a cause....

After 212,000 miles....
.....the pad carriers have worn so much that they can't seat a brake pad properly anymore :-/.....although, when fitting the pads, they seem to seat okay.

.....there is a problem with the expansion & contraction (when getting wet) of the 12 year old calipers, compared to modern asbestos free brake pads.....might explain why it only starts to happen after driving in wet conditions :-/....but doesn't explain why, if I clean the brakes up & re-copper grease them, they are fine in the rain etc, but only for a couple of months....

......Which makes me think that the caliper pad carriers are worn & it's just the copper grease that keeps the pads from clunking for a while until it wears off in the wet :-/

Your thoughts please :)

Title: Re: Clunking front brakes
Post by Snoopy on Jan 17^th, 2010, 7:36am

JC I would totally agree with your own analysis of the situation. Although the carriers "look" OK there is almost certainly some wear there, and that small amount of movement could be causing your " clunk" If all else checks out OK then continue as you are or buy some "new" carriers/caliper assembly...

Title: Re: Clunking front brakes
Post by Jonnycab on Jan 17^th, 2010, 4:38pm

Thanks for the reply Dave :)

I've removed the front brakes again & cleaned them up. The only thing I can find that may be the cause is, when I place the outer pad into the (removed) caliper I can rock it so that the either end can strike the caliper & make a 'clunk'.
There doesn't seem to be any visual wear in the actual cailper though, although as you say, it probably doesn't take alot. So maybe it is time to replace the calipers.

The only other thing I can think of as a reason why this is happening, is maybe the anti-rattle spring clips have lost tension & they're not holding the caliper & pad carrier together tight enough (they don't seem as difficult to get on as they used to) :-/.

I reckon I might try some new spring clips before I condemn the calipers.... & for now, I've bent them back a bit so they give more tension (were harder to get back on) :)

Title: Re: Clunking front brakes
Post by Jonnycab on Feb 4^th, 2010, 1:46am

Problem sorted, I hope.......It seems to have been the anti rattle spring clips that were causing the problem.

Soon (a few days) after cleaning, re-greasing & re-fitting the brakes it rained again & back came the 'clunk' ::). As I mentioned in the last post, the spring clips seemed easier to get on than they used to. Even when I bent them back a bit, I could still fit them by hand (no pliers).

I bought a new pair of spring clips from the local car spares shop (£7.50) & was surprised how diifficult they were to fit. They had so much more tension. I had to use a large pair of mole grips to get them in & even then it was a bit of a struggle.

That was a week & a half ago & the car's been driven on plenty of rain soaked roads since....& so far, no more clunking noises from the brakes :D.....so hopefully, sorted for good :)

Title: Re: Clunking front brakes
Post by tlundkvi on Feb 4^th, 2010, 7:33am

Good you got it sorted. Probably a good idea in the future is to change the anti-rattle springs at the same time as the pads. I'm not sure if it's the culture or not, but over here when you buy pads the salesman always asks if you want the kit with it and people usually take them. But then again on e.g. ebay you see big companies selling nothing but discs and pads and are puzzled when you ask for the spring/mounting kit.

Title: Re: Clunking front brakes
Post by Jonnycab on Mar 26^th, 2010, 5:02am

Update ;)....

New spring clips didn't solve the problem ???....the clunking came back again >:(

So another strip down & inspection (still can't see anything wrong), clean & regrease again & all was fine again for a while...then it came back again >:(.....worse ???

The only thing now I can think of being the cause of the problem, is maybe worn slide pin rubber sleeves....causing the caliper to shift & knock the pads against the carrier when the pads grip the disc :-/

Being that the piston rubber seals are looking a bit wrinkly & the slide pin rubber sleeves may well be worn, then I reckon I'm gonna have to bite the bullet & get two new calipers :(.....got a price at £45 each (exchange), so not so bad :)....a bit more expensive that buying a seal kit, but a lot less hassle ;)

Lets face it, she's nearly driven to the moon now ;D

Title: Re: Clunking front brakes
Post by Jonnycab on Mar 29^th, 2010, 9:04am

Okay, I decided that new calipers was not a cost that I needed right now (£90 the pair), so have ordered new sliding pin rubber sleeves from Bigg Red (£7.90 for 4).

Should get them tomorrow, so will fit them straight away....then give it a few days to see the outcome.

I'm praying that this is gonna fix the problem, as it's starting to drive me a bit potty now http://i70.photobucket.com/albums/i101/jonnycab/smileyphp2.gif

Title: Re: Clunking front brakes
Post by Jonnycab on Apr 1^st, 2010, 10:24pm

I fitted the new sliding pin rubber sleeves on Wednesday.....& the brakes were fine, until I drove through a few puddles & applied the brakes.....'CLUNK' ..... http://undergroundfreakz.com/s/contrib/dvv/boom.gif

Looks like new calipers then http://undergroundfreakz.com/s/contrib/unknown/face7.gif

It's not really the cost of shelling out for new calipers that bothers me, it's the fact that I can't work out why the brakes are doing this. The amount of times I've stripped down, cleaned, re-greased etc & not found anything wrong is really starting to bug me http://smilearchive.com/s/otn/angry/blxsuspicious.gif

Starting to think it may be something else being affected by water......wishbone ball joint rubber split ?...No !!.........track rod end rubber split...No!!......everything suspension & steering wise, apart from the struts & wheel bearings, is under 3 years old & believe me, I've checked every ball joint & bush, & all are good http://smilearchive.com/s/contrib/owen/smoke.gif

I've tried 2 sets of pads (TRW/Lucas & QH) now & a new pair of QH discs. Is it possible that pattern pads are suddenly being made to a different spec to the originals?.... i.e...slightly smaller in length/depth/width ? http://smilearchive.com/s/cwm/3dlil/eek13.gif

Sounds like nonsense I know, but this problem really is winding me up....it makes no sense http://smilies.crowd9.com/otn/confused/fie.gif

Title: Re: Clunking front brakes
Post by Jonnycab on Apr 10^th, 2010, 5:13am

Okay then....last ditch attempt at trying to solve this problem....just purchased some Mintex pads off Ebay....listed as proper 2.3 Scorp pads & not Scorpio/Mondeo MK1/2 pads that I've bought in the spares shop before (although they share the same front calipers)

I still can't find anything wrong with the calipers. No evidence of wear in the actual hardware of the caliper & I'm kind of convinced that if I shell out for new ones, then the problem will still exist & my wallet is going to be £90 lighter for no reason http://smilearchive.com/s/cwm/cwm/uhoh.gif

I'm working on a mad theory that TRW/Lucas & QH pads aren't made to proper OE spec.....we'll see http://undergroundfreakz.com/s/contrib/AoErat/awink.gif

P.S....I did replace the pad carriers a little while ago, but to no avail http://smilearchive.com/s/cwm/cwm/hmh.gif

Title: Re: Clunking front brakes
Post by Snoopy on Apr 10^th, 2010, 7:57am

If its still there then I say it is NOT the brakes . You have convinced yourself that it has to be. It could be something else. Awful amount of force exerted on other suspension parts when the car is under braking. It only takes the smallest amount of movement to create a "clunk" and you checking the suspension even with the best will in the world will not be able to exert the same force as braking does. It could even be the top of the suspension leg moving slightly. Me, I would now get to the stage of ignore and let it develop, but its easier said than done. Good luck in your quest JC.

Title: Re: Clunking front brakes
Post by Jonnycab on Apr 11^th, 2010, 2:30am

I appreciate your advice Dave & consider all you say http://undergroundfreakz.com/s/cwm/cwm/wink.gif, but I've been over the whole front suspension & nothing is wrong http://smilies.blazemint.com/s/contrib/ruinkai/sh1a.gif...strut mount bushes & bearings were replaced about 18 months ago http://smilearchive.com/s/cwm/cwm/smirk.gif

It's defo the brakes....I'm absolutely positive about it http://smilearchive.com/s/cwm/cwm/wink.gif

I could just ignore it & let it develop, but it's been doing it for so long now (nearly a year) & it's still just the same really. It doesn't really notice when breaking at speed....more at low speed..i.e when pulling up on the taxi rank to pick up a fare....& even then, it doesn't do it all the time.
A few people have mentioned it & one even refused to get in once because the sound was so loud when I pulled up beside them, they thought there might be something seriously wrong......I can't blame them, I'd probably do the same.

This car has been through 2 council licenced vehicle MOTs & one proper MOT since the noise started & it has not failed on any suspension or brake related issues http://smilearchive.com/s/cwm/cwm/wink.gif

This is perplexing to say the least & has me completely baffled....but there has to be a reason, & I won't rest until I find it http://smilies.blazemint.com/s/otn/angry/paranoid.gif

Title: Re: Clunking front brakes
Post by Scorpio_Mike on Apr 11^th, 2010, 12:38pm

JC,
Read your post last night in the small hours...and it got me thinking...

You've checked all the obvious stuff...but could it be something as simple as an 'object' rolling around on the plastic undertray beneath the engine and clonking against the ARB or chassis rails ?
Maybe something like a socket ?

I seem to recall a story many years ago - maybe I read it in a car magazine - where a chap had a clonking noise in his car and it was driving him mad. Eventually it was found to be caused by a golf ball rolling around inside a sill panel - how it got there I don't know !

Title: Re: Clunking front brakes
Post by Highlander on Apr 11^th, 2010, 11:24pm

Yeah I had the same with a tin of WD40 in the boot behind the trim, everytime i pulled away or came to a stop i got a cluck as it tilted back and forward, spent hours checking underneath only to find it by accident!

If you want to try a set of 2nd hand calipers Jonny i'll pop them in the post.

Title: Re: Clunking front brakes
Post by Jonnycab on Apr 12^th, 2010, 9:50am

Cheers guys, but it's not anything rolling about the engine tray etc http://smilearchive.com/s/cwm/cwm/wink.gif

Thanks for the offer Stuart....pm sent http://smilearchive.com/s/contrib/sarge/TheSmile.gif

Title: Re: Clunking front brakes
Post by Jonnycab on Apr 14^th, 2010, 4:34pm

Right then http://smilies.blazemint.com/s/contrib/sarge/TheSmile.gif.... just fitted the new Mintex pads & the first thing I noticed about them was that they fitted the carrier very snug with hardly any movement. The QH pads didn't seem to fit as well, in that they were a little loose when placed in the carriers. I also fished the old TRW pads out of the shed & put them in the carriers, they were also a bit of a loose fit.

This might make sense as to why it starts clunking after going through water. Maybe the copper grease applied at either ends of the QH/TRW pads & the carriers is cushioning/dulling the blow when the pads move, but when the copper grease gets washed off a little in the wet (one theory in my first post), that is when you really hear the pads clunk as they smack against the carrier http://undergroundfreakz.com/s/otn/confused/icon14.gif

This is of course is just speculation & the real acid test will be to drive it about for a while to see if the problem has been cured. But comparing the Mintex pads with the QH & TRW pads, there is definately a very slight difference in size http://undergroundfreakz.com/s/otn/confused/xolconfused.gif

Title: Re: Clunking front brakes
Post by Jonnycab on Apr 15^th, 2010, 3:04am

So far so good......not a peep out of them tonight. I even took the car through the car wash on the way to work to give the brakes a good dousing.....she needed a wash anyway http://undergroundfreakz.com/s/contrib/sarge/TheSmile.gif

A bit early to really tell though....need a bit of rain & a few puddles to drive through....but I'm feeling optimistic http://undergroundfreakz.com/s/otn/wink/thumb.gif

Title: Re: Clunking front brakes
Post by Highlander on Apr 15^th, 2010, 9:34am

on 04/15/10 at 03:04:31, Jonnycab wrote:

but I'm feeling optimistic

Don't do that with a Scorpio, it'll break! ;D

Title: Re: Clunking front brakes
Post by Mike H on Apr 15^th, 2010, 3:19pm

Yes so far I've found pessimism to be quite successful must be said ;D

Title: Re: Clunking front brakes
Post by Jonnycab on Apr 21^st, 2010, 1:54am

AAARRRGGGHHH.... http://smilearchive.com/s/contrib/dvv/bash.gif

They're not clunking anymore....now, when hot, they're making this horrible moaning noise when I reverse (vibrating ?)...fine when going forward though http://undergroundfreakz.com/s/contrib/ruinkai/wbored.gif

Pads not retracting far enough off the disc due to caliper pistons not behaving as they should ?......or maybe just a wear in period for the pads ?

It's all going a bit cloudy now http://i70.photobucket.com/albums/i101/jonnycab/smileyphp2.gif

Title: Re: Clunking front brakes
Post by Mike H on Apr 21^st, 2010, 11:57am

Possiblee, pads are wearing unevenly so front edge is thicker than the back edge.

So when you reverse the front edge is binding and it vibrates.

Used to get this with my Moto Guzzi Brembo calipers, the reason was pistons not sliding properly due to rust. This is pure speculation of course

Title: Re: Clunking front brakes
Post by Jonnycab on May 7^th, 2010, 2:04am

Still not clonking anymore :D......just moaning a little when reversing, as though the pads are sticking to the disc ? ::)

I suppose there is no getting around the fact that this car does really need new calipers ;)

Title: Re: Clunking front brakes
Post by Mike H on May 7^th, 2010, 11:29am

Do calipers wear out that much?

Pads probably rubbing on the disc causing vibration.

Ack-cherlee, if the pistons are a bit stiff they may not be lifting off properly which may be what this is all about.

Have had similar with Brembo calipers (re Moto Guzzi / BMW motorbikes), pistons can seize up meaning strip and rebuild the caliper to clean it out