David Winter 0 Posted November 20, 2007 Hi. My intermitent abs fault is I think the right hand front abs rotor. Sensors are new but the light comes on under heavy acceleration only. Fine all other times. I can get to motorwayspeed if I accelerate normally. The diagnostic check came up with right hand mechanical fault. Question is. VAG only sell the whole hub assembly at £70. Is this what I have to do? Quote Share this post Link to post Share on other sites
was8v 0 Posted November 20, 2007 I got a rear one from VAG not long ago, so if its similar (push fit over the rear of the disc) then they are availiable. Was a pain to get the part number as it is not shown on the ETKA part diagrams (is shown on the bentley). I went for pot luck and ordered the part based on the (useless) description in ETKA. Quote Share this post Link to post Share on other sites
David Winter 0 Posted November 20, 2007 VAG said that they sell the rear rotor seperately £11. But the front comes with the Hub. Quote Share this post Link to post Share on other sites
Roger Blassberg 0 Posted November 21, 2007 Unless you have EDS (a sort of traction control operated through the ABS braking system and standard fitment on a VR6), you may well get different rates of spin for each wheel under hard acceleration, particularly if the steering wheel is turned. This will be detected by the ABS system as lock-up of one wheel and may put the warning light on. Does the light go out once you have stopped hard acceleration? Best wishes RB Quote Share this post Link to post Share on other sites
David Winter 0 Posted November 21, 2007 Does the light go out once you have stopped hard acceleration? I have a VR6 with EDS and have recently replaced the ecu. Im talking about straight line acceleration and not just first gear acceleration. It can also happen in hard mid range acceleration ie 3rd gear at 60 so it must be this rotor. Light stays on untill I turn the ignition off. Quote Share this post Link to post Share on other sites
pete_griff 0 Posted November 22, 2007 it may be that the existing rotor on the car has become too rusted up and is affecting the sensor, or it could be that the rotor has become bent somehow (e.g. just the right sized stone somehow finding its way between the rotor and the hub... :? ) also if the sensors have been fitted recently just make sure that the face of the sensor itself is nice and clean - if it has dirt/grease etc covering it then that could affect it - but from what you've said it sounds more likely to be the rotor. the bad news is that if it is the rotor and you want to remove it to straighten it out etc then to do a proper job you will have to get a new wheel bearing - you could straighten and clean it with it still on the car, but if you want a lasting job then the way forward is to remove it from the hub and give it a damn good clean - see my pics below download/file.php?id=47915&mode=view download/file.php?id=47904&mode=view (you'll also notice in the pic just of my rotor that one of mine was slightly bent when i had them shot-blasted and i hav had to straighten this out) hope this helps :) Quote Share this post Link to post Share on other sites
dr_mat 0 Posted January 30, 2008 Dredging this one up again .. How does the ABS rotor attach to the rear of the brakes? Is it screwed in place? My rotors appear to be "moving" - sometimes they're fouling the ABS sensor, sometimes they're not. They are slightly buckled too, which doesn't help, but the fact that it doesn't happen all the time tells me something is loose.. Quote Share this post Link to post Share on other sites
Supercharged 2 Posted January 30, 2008 Matt - the rears are just a push fit but very tight on the discs so unlikely they would move on there own... I would always recommend new ones as they corrode at the rate you'd need new discs so even if in good nick after a disc change, your likely to need replacements before the next change of discs if you see what i mean.... Things to check - play in rear wheel bearings, calipers not working for whatever reason and corrosion of rear brakes - flakes of metal come off the discs and crud up the sensor... Quote Share this post Link to post Share on other sites
was8v 0 Posted January 30, 2008 Dredging this one up again .. How does the ABS rotor attach to the rear of the brakes? Is it screwed in place? My rotors appear to be "moving" - sometimes they're fouling the ABS sensor, sometimes they're not. They are slightly buckled too, which doesn't help, but the fact that it doesn't happen all the time tells me something is loose.. I had the same problem, car had new discs fitted a few months back and the ABS rotor was jangling around on the back, loose. The new ABS cage was a very tight fit over the back of the disc. Clearly when new discs were fitted previously they just hammered the old one off and it mustn't have fitted tight enough when put back. You may be able to bend it back to fit again but I reckon it will just come loose again. The amount of disassembly required means you may as well just order a new one (circa £11) then the jopbs done inside an hour. Quote Share this post Link to post Share on other sites
dr_mat 0 Posted January 30, 2008 I had the same problem, car had new discs fitted a few months back and the ABS rotor was jangling around on the back, loose. The new ABS cage was a very tight fit over the back of the disc. Clearly when new discs were fitted previously they just hammered the old one off and it mustn't have fitted tight enough when put back. You may be able to bend it back to fit again but I reckon it will just come loose again. The amount of disassembly required means you may as well just order a new one (circa £11) then the jopbs done inside an hour. And tonight it's quiet on the way home. :roll: Insane thing. So it's not much work to swap 'em? You just have to take the brake disks off? Might just go get a hammer and just smack 'em one... :) Quote Share this post Link to post Share on other sites
was8v 0 Posted January 30, 2008 I had the same problem, car had new discs fitted a few months back and the ABS rotor was jangling around on the back, loose. The new ABS cage was a very tight fit over the back of the disc. Clearly when new discs were fitted previously they just hammered the old one off and it mustn't have fitted tight enough when put back. You may be able to bend it back to fit again but I reckon it will just come loose again. The amount of disassembly required means you may as well just order a new one (circa £11) then the jopbs done inside an hour. And tonight it's quiet on the way home. :roll: Insane thing. So it's not much work to swap 'em? You just have to take the brake disks off? Might just go get a hammer and just smack 'em one... :) OOOPS I'm talking about the REAR ABS rotors. The fronts are part of the hub assembly iirc. Sorry for the confusion! Quote Share this post Link to post Share on other sites
dr_mat 0 Posted January 30, 2008 Indeed, I'm talking about the fronts... Quote Share this post Link to post Share on other sites
David Winter 0 Posted January 31, 2008 Guys. Just to conclude this I decided to replace the sensor again. I had put brand new OE sensors bought from the dealer less than a year ago on and this is why I was so confused as I had removed the discs and cleaned any rust etc off the rotor and painted it and could not detect any significant warping but still VAG com was saying right hand mechanical fault. So I decided to replace the sensor again with one from gsf as these are only 15 quid. Guess what. NO more problems! Quote Share this post Link to post Share on other sites
David Winter 0 Posted March 8, 2008 Guys I cant believe this. Ive had just over a month with no problems but today the fault is happening again. I can only now conclude it must be a slightly warped rotor and a brand new sensor solves the problem temporarily. Any comments? Quote Share this post Link to post Share on other sites
blue95 0 Posted March 8, 2008 The rotor is held onto the hub with screws, unfornuately the only way you can change them is by removing the hub and destroying the bearing in the preocess. I am sure you can buy the rotors seperate, but you will have to bduget for new bearings as well Quote Share this post Link to post Share on other sites
