AP brake problems.
Discussion
This has been an ongoing issue since a month or 3 after fitment back in Sept 05, and is still not resolved. There have been numerous phone calls etc from this time. Its got to the point, were he hardly drives the car anymore, as its that annoying.
Has anyone else had problems ?
In brief, bump through foot pedal, which also ends up being felt a little through the steering, and oddly also through the gearstick under breaking.
Initally new rear pads were supplied....this did not fix it.
Then eventually new front discs were supplied. This did fix it on the short term, but the problem as now returned. The new discs were NOT supplied as per the original kit.
It was new discs only. Not complete discs/bells already bolted up, as the kit came originally.
So basically he has lived with this problem for almost 12,000 miles. Returning several hundred miles to the approved installer, isnt really an option, due to distance, and time/costs involved.
Phoning AP is a waste of time, they just direct him back to the installer.
Surely it isnt the only one out there with problems ?
Has anyone else had problems ?
In brief, bump through foot pedal, which also ends up being felt a little through the steering, and oddly also through the gearstick under breaking.
Initally new rear pads were supplied....this did not fix it.
Then eventually new front discs were supplied. This did fix it on the short term, but the problem as now returned. The new discs were NOT supplied as per the original kit.
It was new discs only. Not complete discs/bells already bolted up, as the kit came originally.
So basically he has lived with this problem for almost 12,000 miles. Returning several hundred miles to the approved installer, isnt really an option, due to distance, and time/costs involved.
Phoning AP is a waste of time, they just direct him back to the installer.
Surely it isnt the only one out there with problems ?
M8LC N said:
When you say 'bump' through steering etc, is it like a constant judder/vibration and even the interior mirror blurs?
Cant say bout the mirror, as Im describing for a friend who owns the car. I havent personally driven it to feel the problem.
But it feels like it either has a warped disc ( as best can tell, it doesnt. Outer edge runs tur on a dial guage, cant test anywhere else due to grooves on disc ), contamincation on the disc, or a cracked disc.
All have a similar feeling on the pedal, although it doesnt appear to be any of those things....
As for the bump, I have seen visual movement and felt it on the gearstick under braking, which is very weird.
Its light, but noticeble.
Under foot, apparently its damn annoying. He has tried driving easy, and thrashing the crap outta it, although its difficult to get any real heat/abuse into the breaks, with the car being only standard, and relatively slow.
huffy said:
I am a long way from the worlds best mechanic but is it just one bump each time the brakes are applied or a series of bumps - if the former, it sounds like the callipers may be moving on their mounts? Does it happen in reverse as well?
bump bump bump for the duration the brakes are applied.
This may not be helpful and I don't have AP's but I had some new discs on mine shortly after I bought it. Subsequently I thought the new ones had warped. The car had been standing for a while and I knew there was a rust build up on the discs. Several hundred miles of normal driving visually cleaned the discs but the feeling of them being warped remained. I had got as far as booking in for some replacements but beforehand a period of sustained progressive brake testing actually cured the problem.
Given however a period of 12k miles and a variety of driving styles anything like this would seem outside the realms of probability. Guess my point is these things are not always readily visible. Seem to recall also that AP's require a specific type of bedding in - something in excess of what you would normally do.
Sorry, no more suggestions at the moment - will obviously shout if I think of anything!
Given however a period of 12k miles and a variety of driving styles anything like this would seem outside the realms of probability. Guess my point is these things are not always readily visible. Seem to recall also that AP's require a specific type of bedding in - something in excess of what you would normally do.
Sorry, no more suggestions at the moment - will obviously shout if I think of anything!
silentmonkey said:
You might want to check the tyres. If the tread were detaching then that would cause a repeated bump especially under braking.
Also if a single bump that might be suspension related. Damper, bushes, roll bar etc.
Also if a single bump that might be suspension related. Damper, bushes, roll bar etc.
The car has less than 15k on the clock.
Tyres have been replaced during that time anyway.
Suspension is fine, A due to low milage, and visual inspection, and B, shocks/springs have also been upraded during that time.
There is a problem with the brakes. Standard brakes were fine for the first couple of thousand miles when he bought the car. Problem has only occured after the AP's were fitted...
Diagnoses attempts are one thing. But has anyone else experienced similar problems ?
See if this helps:
www.stoptech.com/tech_info/wp_warped_brakedisk.shtml
Would you say it's 1 "bump" per wheel revolution? Chances are it's just uneven pad transfer or something.
www.stoptech.com/tech_info/wp_warped_brakedisk.shtml
Would you say it's 1 "bump" per wheel revolution? Chances are it's just uneven pad transfer or something.
Edited by mackie1 on Tuesday 13th February 18:14
Im aware of it, and have read it before, and it could be a possibility.
If indeed it is the problem, why is the kit being sold with a combination of pads/discs that wont work for a road car ?
As Ive said, abuse has been tried to "clean" the discs, but it just isnt happening. Either the discs need replaced or skimmed, or they need that, and a more suitable pad compound is required, so that that wont happen, if indeed it is part of the problem.
Given new discs did briefly cure the problem, it is a strong possibility it could be pad deposits.
Thats up to AP and/or the installer to supply though. We arent about to skim new discs, that may require sending back to AP for inspection ( more postage costs )
We have used DS2500's on many cars, and never experienced such problems though. My own included. Although my discs are floating, so that may smooth things out a little. But pad deposits should still be felt under foot. Ive never expereinced that, and most of teh time my car is driven very easy ( Mines a custom AP kit made by an independant specialist )
If indeed it is the problem, why is the kit being sold with a combination of pads/discs that wont work for a road car ?
As Ive said, abuse has been tried to "clean" the discs, but it just isnt happening. Either the discs need replaced or skimmed, or they need that, and a more suitable pad compound is required, so that that wont happen, if indeed it is part of the problem.
Given new discs did briefly cure the problem, it is a strong possibility it could be pad deposits.
Thats up to AP and/or the installer to supply though. We arent about to skim new discs, that may require sending back to AP for inspection ( more postage costs )
We have used DS2500's on many cars, and never experienced such problems though. My own included. Although my discs are floating, so that may smooth things out a little. But pad deposits should still be felt under foot. Ive never expereinced that, and most of teh time my car is driven very easy ( Mines a custom AP kit made by an independant specialist )
I've had the APs fitted for just over a year now and not had any problems. I didn't do anything particularly fancy as far as bedding in goes and I do tend to keep my foot on the brake when I come to a stop as mine's an automatic.
Yours doesn't seem to be a common problem with the APs, so don't dismiss the idea of the cause being elsewhere (wheel bearings, steering, bushes, alignment etc.) Also, low mileage is no indicator of condition of these things.
Yours doesn't seem to be a common problem with the APs, so don't dismiss the idea of the cause being elsewhere (wheel bearings, steering, bushes, alignment etc.) Also, low mileage is no indicator of condition of these things.
L8 VXR said:
Please keep us informed as next week my vxr tt is booked in to WRC Tech for further mods, and a full AP front and rear brake inc calipers up grade kit.Im'e worried!! 
Dont be worried. So far, the jist of the thread seems to indicate few, almost none have had problems.
This kit was one of the very earliest kits though. Not that it should matter though.
I had my AP brakes fitted about 6 months ago went through full bedding in process and no problems, except once when first fitted brakes seem to have bound on overnight but released with no further problems until two months ago. Brakes randomly bound on overnight about three times so started to park with hand brake off and in gear something I’m used as I also have a Caterham. About this time noticed juddering under braking, worse under light and moderate braking this progressively deteriorated until it became virtually undrivable. Fortunately had used a well known and respected company to install and they replaced discs and pads, seems to have resolved the issue apart from the brakes have had one slight bind on.
Pads sticking to the disc, wouldnt be an uncommon thing.
Ive had this on a few cars, especially if they might sit for a day or 2. Its not a concern though.
Latest update is that there may be a resolution in hand for the judder problem though. Wont say anymore than that though, until it actually happens.
Ive had this on a few cars, especially if they might sit for a day or 2. Its not a concern though.
Latest update is that there may be a resolution in hand for the judder problem though. Wont say anymore than that though, until it actually happens.
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