On the advice of the Garage I had the rear pads and discs replaced during the last annual service. 2 weeks later there was a loud knocking noise while braking so I took it back and they said the pad carrier on one side had caused the pad to wear out very quickly. I didn't really understand but they changed the disc and pad didn't charge me so I was happy. About 2 weeks after that (last Friday) we got the knocking noise again. This time they are saying that the pad on the other side has stuck to the disc. They think it is because of something sticky that has been put on the disc, i.e cleaning fluid. I haven't washed the car since the previous work was done. It all sounds a bit fishy to me and they said they would charge me if it turns out to be "something sticky" on the disc.
Has anyone experienced pads sticking to discs due to some "foreign" fluid on the disc??
Many Thanks
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If there was any foriegn matter on the pads or disc, a quick inspection after pads had been removed would show this...most times any grease, tar etc on the disc would mean you get a high pitched squeal as well.
After a while these deposits can slowly burn / abrade off...but not sure how long it takes.
Personally if it was me, I'd want to know if the rear calipers were sticking and the knock you hear (which should be a single knock unless discs are warped) is the sound of the calipers freeing.
It is also possible that if they have not fitted original manufacturer's parts that the pads are not moving smoothly in the caliper.
IF it is something sticky and they charge (which should not be much) then fine, but if it is any of the above
faults it will re-occur. As always maybe worth getting another garage to look at it if you suspect a rat.
Saying that I got a knocking noise (single clunk) from my brakes when applied (although it was a civic) after new ones were refitted, but only when Car after reversing, loading the rear of the car made it go away, took it to dealer who found nothing wrong and said it maybe just bedding in. Strangely it was worse in the rain/wet. I was starting to suspect some rear suspension fault when the problem slowly went away after another 1000 miles.
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Discs and pads rust together (or rather the discs rust and the pads stick) so if you washed the car and then did not use it for a week...alloys exacerbate the problem as washing alloys = water on discs.
I always wash car and then drive it : from experience having had knocking sound due to rusting brake shoes/drums or disks /pads on Fiesta/BMW /Rover and Mercedes.
IF the slides the pads or discs are corroded or have a build up of dirt, that makes things worse, or the handbrake siezes on (after washing).. etc...
madf
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This time they are saying that the pad on the other side has stuck to the disc.
I dont understand that statement. Did they mean permanently ? That's just not possible, because the disc couldn't then rotate at all.
Can you be a bit more specific about the knock ~ is it a single knock when you first apply the brakes, or is it a rhythmic knock? At what road speed does the knocking occur? Even at 10 mph the wheel will rotate at about 5 times per second, so I would expect any noise you might get would be a vibration at 5 cycles per second rather than a knock.
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L\'escargot.
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Even at 10 mph the wheel will rotate at about 5 times per second, so I would expect any noise you might get would be a vibration at 5 cycles per second rather than a knock.
My mistake. Substitute 2.5 for 5 ~ not that it alters the nub of my argument.
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L\'escargot.
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I don't follow the logic, here. 2 weeks after repair the repairing agent, who had fitted 2 new discs and pads has to replace one side because the work was not done properly. Now, after only 4 weeks the other side is showing the same fault, apparantly. It sounds to me as if they have built the same fault into the side that is now playing up.
Changing discs and pads is not rocket science. I would be asking the repairing agent if they would like another oportunity to do the work they have supposedly done.
The only "sticky" substance around should be the preservative applied to the discs for storage. If this is the cause then it's because they didn't clean it off properly.
Whatever, after only 4 weeks there should be no problems at all, if the job was done properly in the first place.
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Thank you very much for all your replies which have been very helpful. The knocking was a rythmic sound which got worse when the brake was pressed. Both times when I had problems I only got to the end of the road and only got to 10mph when I noticed it. I felt the car was unsafe to drive so I got my breakdown company to recover the car to the Main Dealer.
It does not seem right that a pad can stick to a disc which can turn as the the very act of turning the disc would break the adhesion between pad and disc and the pad "should" spring back away from the disc.
I'm defiantely going to argue this point and probably won't go back there for repairs in the future. Since this has happend a couple of people have told me they have had problems with sloppy work from this main dealer.
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They are lifting your leg, its not down to something sticky on the disc, its a problem with their workmanship for an educated guess. They either have failed to assemble the brake correctly or it could be that the caliper is sticking. Either which way it was fine before they touched it and I think that it is down to them to sort it out free of charge. If it is the caliper that is sticking, then why is it doing it now and not before? They should have noticed the first time if the caliper was seized, but my gut instinct is that they are trying to cover up their faulty workmanship. And this is a main dealer as well???
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Sounds like pad is sticking in the carrier. Maybe they didn't clean up the carrier (pads should have a spot of copper grease on their edges too).
Drive a couple of miles and carefully feel the discs both side with a fingertip - if one is noticably hotter than the other then a pad is sticking. Be careful though - a sticking pad can make a disc very hot!
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I went back to the Dealer yesterday to pick up the car and they said they weren't going to charge me for it. They still tried to blame it on something sticky on the disc or their new excuse that I had parked in a puddle!! I assured them that I hadn't parked in any puddles and that I thought it was highly unlikely to be something sticky on the disc but I just wanted to get out of there so I didn't hang around to argue about it too much.
Since they didn't charge me and they gave me the loan of a new Fiesta (which I thought is quite a nice car) I think I might just so business with them again.
Thanks again for all your help.
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