Hi guys, I replaced the front left disc (and right side and pads) around 4 thousand miles ago because the disc was starting to warp.Ran them in with no heavy braking.. After having some wobble (again) in the steering wheel when braking I checked them this morn, and the left disc is starting to warp again. I put pagid discs and pads in last time. Any ideas why its doing this, its only the left side that warping. thanks in advance guys.

Is the caliper sticking? I had 1 that was sticking and it causes the disc to get very hot and warp.

did you use grease after replacing the pad and also did you check the caliper pins?

No the caliper is not sticking, and did grease the pads and pins. I'm at a bit of a loss now. thanks.

No the caliper is not sticking, and did grease the pads and pins. I'm at a bit of a loss now. thanks.

Did you spin the wheel to make sure it ran smoothly while up in the air? no expert but could one of the bolts be misalligned/ not tightened as much as the other so as it is catching and heating up to warp it? or maybe a washer extra/missing that sort of thing? if one side of the pad is closer to the disc then maybe that could be an issue. did the pad wear the same accross it or was it misshaped?

You should check that the guide pins are not bent. Had this happen myself, and it stopped the pad moving fully off the top of the disc when the brakes were off. Resulted in a massive amount of heat build-up, warped disk, 'wedged' pads, and I ended up replacing the bearing assembly as well (though I was never 100% if the heat had caused damage to the bearing, or if it was just coincidence). That was all down to a very slightly bent guide pin. It looked fine, but if you put it in a drill on a low speed and spin it, any bend - even a slight one, will become very evident.

Its possible its the discs themselves simple things like sitting with youre foot on the brake can do it or a guide pin or sleeve has a bit of rust on it

When you fitted them did you clean the hub before reseating as any debri in this area that throws it out by a mil or two will cause it to warp when it's heated up .

Hi guys. Had a look tonight and as far as I can see,1 of the guide pins has a wobble on it and is about 1mm out of true. And the other 1 is not to clever. Yes gents, all was clean when I put the discs and pads on, grease where it was supposed to go and everything. The pads are not wearing unevenly though. Cheers.

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Hi guys. Had a look tonight and as far as I can see,1 of the guide pins has a wobble on it and is about 1mm out of true. And the other 1 is not to clever. Yes gents, all was clean when I put the discs and pads on, grease where it was supposed to go and everything. The pads are not wearing unevenly though. Cheers.

I'd replace the guide pins ASAP. You can get them for about a tenner a pair from eBay.

Here's where I got mine from: http://r.ebay.com/rMslQ9 NOTE: Those are the Mondeo ones! They have a few different Focus ones, too. But check they're right before ordering.

(By the way, I'd hazard a guess that there's actually nothing wrong with the disc).

Yeap should get the new pins tomorrow then will give them a try.i have a new disc to put on to try.as the disc on the car is a little warped,does anyone think its possible to put it on a lath to have it ground down,as its only done 4 thou miles and there isn't a mark on it.

I'm curious to know how you know the disc is warped, or what's making you think that it is? You can get the discs resurfaced on a lathe (I saw Edd China do it once to remove rust), but we're talking microns - there's no way you'd see it with the naked eye.

When I mean no marks, I meant no grooves or chips. If I jack the car up and spin the wheel I can feel it binding in 1 spot and there's blue patches on the disc,I'll take a pic tomorrow when I take it off, hopefully if the pins arrive.

I'm curious to know how you know the disc is warped, or what's making you think that it is? You can get the discs resurfaced on a lathe (I saw Edd China do it once to remove rust), but we're talking microns - there's no way you'd see it with the naked eye.

That method isn't cost effective on the average car. It is measured with a run out gauge or if it's really bad you will see it with a straight edge..

That method isn't cost effective on the average car. It is measured with a run out gauge or if it's really bad you will see it with a straight edge..

No, it's not. He only did it because replacement discs weren't available for the car he was working on.

I'm having this exact same problem. I replaced the discs and pads all round when I got the car 2 years ago, but the judder/wobble returns within about 10k miles. I might try the guide pin test but...

I also think that there a bit of a 'lip' on the caliper carrier where the pads go. Is it ok to grind it smooth again? I also think that the pads are not coming off the disc all the time

Changed the pins and disc this morn,and problem solved .pins were about 1mm out of true.thanks everyone for your input.cheers.

Great news mate!

Changed the pins and disc this morn,and problem solved .pins were about 1mm out of true.thanks everyone for your input.cheers.

Unfortunately, brakes work to such small tolerances that even a tiny fault can have big consequences.

This leaves a question - how do the pins get bent in the first place? I have a theory. Now, I'm no big fan of garages - too many iffy ones about and I might just be cynical. It's my belief that when a garage changes the brake pads, they do it the quickest way possible and don't remove the caliper fully. They undo one guide pin - usually the lower one, lift up the caliper, and push against the remaining guide pin to wind the caliper back in, bending the pin in the process.

Just a theory. But I doubt they bend by themselves.

I changed the pads last time, but didn't notice if the pins were bent . But you might be right BigD as it was the top pin that was bent the most.