Brakes acting up after lowering?

[marrick92]

Ive had this problem for a while now and have just ignored it but i think its time to get something done about it! I had some coilovers fitted a few months ago and immediatly after, some odd things began happening..

When i set off, there is a very odd noise i cant really diagnose myself. I'm guessing its coming from the brakes because the brake peddle springs up when you try to press it, it doesnt sound like a grinding or any usual mechanical noise you would hear. its like a tinging or a vibrating sound. Possibly ABS??? This only happens when i set off from a stop up to about 7mph, it goes off when you quickly tap the brake a couple of times or when you speed up, there is no effect when using the brakes at speed, the brakes still work perfectly its just a bit wierd. VagCom shows front right ABS wheel speed sensor, but that has been coming up on the VagCom before i had the coilovers fitted. I tried replacing this sensor but the fault code still shows (comes back on straight after cleared)

Any help or answers would be great!

 

[jay1601]

how low have you gone ?

did you replace the ARB ?

if your gone fairly low and you didn't replace the arb. your more then likely have the driver side driveshaft rubbing on the ARB

 

[marrick92]

I fitted an extended front Arb to stop it rubbing on the driveshaft, so thats not the issue. This noise now is more tingy and sounds like a spring recoiling or something, it started literally when i set off it the car from having the coilovers fitted, its been lowered a few months now, cant remember when exactly.

Cheers

 

[murran]

the noise is the abs pump working when it shouldnt be. the pump cuts in when coming to a stop under even light braking, and then setting off again.
youve replaced the sensor? check out the wiring. unplug the sensor and the abs unit, find a wiring diagram, get your multimeter out and check the continuity of each wire to the abs unit. if this is ok.....
take the brake disc off and check out the gapped ring on the back of the hub..... is it straight? how big is the gap between it and the sensor. gap might be too big to read.

 

[moredoor]

Yep sounds like the ABS could be kicking in, more an likely who ever fitted the coilovers damaged one of the ABS sensor wires.

 

[marrick92]

I'm fitting some new discs this week some time so i'll check it all out when im on with them, any ideas where i'll find a wiring diagram? i might sound a bit stupid but where is the ABS unit located? and thanks for all the helpful replies!

 

[Prawn]

absolutely the ABS triggering as you pull away. Not directly related to the lowering, but it'll be a wheel speed sensor that's been knocked, or the wires pulled during fitting the coilovers.

When I first had someone else fit some suspension for me they pulled the ABS wire somehow, it looked fine, and the sensor was undamaged, but it came up with an intermittent ABS fault and caused the exact same juddering and ABS triggering on pulling away.

 

[<tuffty/>]

If you have a prob with the ABS sensor then I would sort that out before trying to track anything else down...

What was the actual code VCDS came up with?

<tuffty/>

 

[marrick92]

Fault codes are;
2 Faults Found:
00285 - ABS Wheel Speed Sensor; Front Right (G45) ------------------------- wheel speed sensor
35-10 - - - Intermittent
00285 - Wheel speed sensor
04-10 - mechanical - Intermittent

But please note, i have had a problem with this sensor since i bought the car and the ABS only started making noises after i had it lowered. I replaced this sensor around 2 months ago but the fault codes still came up and the ABS still makes horrible noises.

Cheers for the help

 

[<tuffty/>]

You need to get that problem fixed before you stand a chance of getting anywhere... IIRC Dane had similar issues on his S3 which turned out to be a break/crappy fix on the ABS sensor wiring... wasn't the sensor itself... IIRC it was making the ABS come on for no reason...

Check the wiring, get the fault fixed and then see where it goes from there... can't hope to fix a braking issue like this if there are faults with the sensors that control it

If the wiring is iffy then lowering the car may well have made it worse

<tuffty/>

 

[marrick92]

Thanks for your help mate, ill check out the wiring tomorrow and ill see if i can get it sorted!

 

[marrick92]

ok when i had the wheel off i found no breaks or weaknesses in the cable. The sensor was replaced not so long ago so im stumped..
Put it on the VCDS and found out there is no reading from the front right wheel speed sensor when moving, and at a standstill the front right reads 255km/h whilst the others are at 0?

This is the VCDS readings, time x wheel speed