Brake problem, any ideas?

[H182]

Posted this a couple of times before but have never found a solution.

I have a strange intermittant problem when braking gently, i get a vibrating sound (sounds similar to ABS) and I can feel the pedal vibrating also. Also when braking harder (not planting) I can feel something through the pedal as if its crunching something, the harder I press it the more it does it. The brakes appear to stop the car fine though. Someone suggested it might be rust on the disks but I have just had new disks and pads put on last week and its still doing it! Could it be air in the system or a faulty abs sensor or something? Any suggestions would be appriciated.

Thanks

 

[ben_p]

hi m8 i have the same thing on a mrk1 172, i thought it was the abs, its like a grinding, i can feel it on ma footn too, i have no idear, althugh it may be shot drive shafts

 

[H182]

hmm, hope it isnt. Would they have gone on a car thats done 47k? Its just had a service and MOT and they didnt find anything wrong. Depends how much they check it though..

 

[Dan@SJM]

more than likely warped discs.

 

[Lunner]

Strange if you have just had new discs and pads and its still doing it.

Shot driveshafts usually make themselfves apparent inteh form or vibrations in the stearing.

Check the run out on the discs, could be if they weren't sitting straight of there is something under the one side and they are slightly on the piss could be causuing teh vibration.

Take them off and wire brush teh arse end of the discs and the hub mating surfaces, and make sure there isn't aythingunder them.

Does the wheel vibrate, or just the pedal?

 

[ben_p]

the pedal grinds, mien is on 37k

 

[H182]

Its just the pedal, nothing at all through the steering. Had the problem before the new disks were fitted, guess the garage that fit them would have noticed if they werent straight. Its an intermitant problem too, strange how it doesnt do it all the time.

 

[marvel]

I have a mk1 172 here and did have the same kinda problem.

had my wheel bearing replaced and ever since then it was making the noise. Took it back to the garage and they couldnt work out what it was. When I had the wheel off my acr and turned the disk it would get really stiff at one point.

My car had to go in again to get new rear shocks, and since then the problem hasgone and is yet too come back.

I think it was to do woth how they set the disk on the hub and if it was at a slight angle it would push on the calipers a bit more than normal.

This is what I think it was but I am not certain that it was. All I know is that it has noe gone

PS- This was happening on my Rear Left disk.

 

[Lunner]

Right, if it gets really stiff at one point the discs isn't on straight.

When you replace the bering you have to remove the discs.

Easy to get some crap between the disc and hub not making ti sit straight.

If its just comming from the pedal have you thoguth it might just be the pedal.

Doesn't sounds like its anything to do wiht the discs etc unless the stearing is shaking, almost sounds as though the pads are down to the metal backing padfs, apart from they aren't

 

[H182]

What do u mean could just be the pedal? The sound it makes is quite loud and the vibrating is harsh. Its not like a grinding noise like when pads are worn its different, hard to explain. Don't they spin the wheels to check when they do MOT? so they would have found the problem if that was the case?

 

[SeanM86]

grrr i have this problem too and have mot tomarrow. Stupid abs light keeps comin on too. Tho when i took it to the garage the mechanic took the car out for a test drive and the light never came on. Really annoyin, but came back on just before i got home lol. So hopefully if i dont pass mot then they can maybe tell me whats causin the problem....grrr

Did you get yours sorted yet cyberblob???

 

[H182]

Not sure. The garage replaced a bust wheel bearing and said that might be the fault. The guy said that both of the ABS Sensors are 'split' (whatever that means) so if it carries on doing it they will need replacing. Its an intermittant problem and not done it yet so fingers crossed it was the bearings.

 

[Jono_GTi]

I have this exact same symptom. I'm hoping a disc/pad change all 'round will sort it but I'm not confident it will. Mines a Mk2 172 with 34k on the clock. It IS annoying, and braking performance on mine is poor too - I think it's brake fade?