Vibration under braking
Discussion
Hi all, my mk1 Seat Leon cupra r has had this problem for a while now and it's getting worse. Basically under light to moderate braking at speeds in excess of 30mph the steering wheel vibrates and this has progressed to the entire car shaking now. I've changed front discs and pads but it hasn't helped. I've had a mechanic go over the car, including checking the brakes on a rolling road but he can't find any problems anywhere on the car that could explain this. It only happens under braking.
So we're at a loss and I'm hoping someone here has experienced the same thing and can advise.
So we're at a loss and I'm hoping someone here has experienced the same thing and can advise.
There are many things that this could be, and although you have been told that the mechanic has checked your brakes on a rolling road, I suspect that he actually means an mot type brake tester.
Things to check:
Remove all 4 wheels & discs & physically clean all mating surfaces between the hub/disc/wheel as any debris/rust/dirt in here can cause this exact problem.
Whilst you have the wheels off whip them down to your local tyre fitting shop & get them to spin the whels up on the balancing machine to make sure there isn't any of them buckled.
Check all suspension joints for play on your front suspension eg ball-joints/track rod ends etc as play here CAN also cause this.
Things to check:
Remove all 4 wheels & discs & physically clean all mating surfaces between the hub/disc/wheel as any debris/rust/dirt in here can cause this exact problem.
Whilst you have the wheels off whip them down to your local tyre fitting shop & get them to spin the whels up on the balancing machine to make sure there isn't any of them buckled.
Check all suspension joints for play on your front suspension eg ball-joints/track rod ends etc as play here CAN also cause this.
Thanks, yes it was an mot brake tester, though he described that it measures run out. On reflection though it probably doesn't have the required accuracy. He did clean up the hubs and re-seat the discs but it didn't help. He's also gone over all the bushes and steering and suspension but didn't find anything significant.
I'm seriously considering getting the discs skimmed on the car but I'll see what the disc supplier says first. The discs are a decent brand but admittedly they were also the cheapest ones I could find so maybe they've warped.
I was surprised to read that EBC recommend skimming of new discs after fitting.
I'm seriously considering getting the discs skimmed on the car but I'll see what the disc supplier says first. The discs are a decent brand but admittedly they were also the cheapest ones I could find so maybe they've warped.
I was surprised to read that EBC recommend skimming of new discs after fitting.
I decided to venture into this section of the forum to ask a very similar question, so rather than starting another similar thread I'll chip in here.
My MK2 Mazda 6 also has a vibration under braking, but one which gets worse after a period of enthusiastic driving. Under normal conditions, braking from 100kmh (I'm in Australia) exiting a motorway etc. it feels fine. However, under occasional heavy braking from say 120kmh I can feel a slight vibration.
On Saturday morning I was running late so pushing on down some country roads quite hard. I braked pretty hard from around 120 and there was a really bad vibration, to the extent that I thought I must have had a flat tyre or other serious and sudden problem. I pulled over and all looked well so carried on. Proceeding with caution I found myself in traffic once more and everything felt normal. After 5 minutes the traffic cleared so I tried a number of braking tests from similar speeds and normal service was resumed.
I changed the brake pads 2 months ago in an attempt to eliminate the minor vibration present under normal driving conditions. However it diddnt make any difference. The discs looked OK at the time.
My MK2 Mazda 6 also has a vibration under braking, but one which gets worse after a period of enthusiastic driving. Under normal conditions, braking from 100kmh (I'm in Australia) exiting a motorway etc. it feels fine. However, under occasional heavy braking from say 120kmh I can feel a slight vibration.
On Saturday morning I was running late so pushing on down some country roads quite hard. I braked pretty hard from around 120 and there was a really bad vibration, to the extent that I thought I must have had a flat tyre or other serious and sudden problem. I pulled over and all looked well so carried on. Proceeding with caution I found myself in traffic once more and everything felt normal. After 5 minutes the traffic cleared so I tried a number of braking tests from similar speeds and normal service was resumed.
I changed the brake pads 2 months ago in an attempt to eliminate the minor vibration present under normal driving conditions. However it diddnt make any difference. The discs looked OK at the time.
200bhp - You may have 'Pick Up' where part of the pad surface sticks to the disc face. This can occur after one or two enthusiastic stops. Then every time you apply the brakes the pad catches on the pad material stuck to the disc surface.
Edited by Paul.B on Tuesday 28th January 15:11
OP - I would check the disc to hub and wheel to hub/disc interface again. If you had this problem with the old set and now fitted new Pads/discs it is unlikely to be an issue with both sets. Also double check.....
Steering rack mounts
Calliper mount bolts
All suspension bushes
Wheels are not buckled
Check the rears too. You may have a problem at the back transmitting itself through the car.
Good luck
Steering rack mounts
Calliper mount bolts
All suspension bushes
Wheels are not buckled
Check the rears too. You may have a problem at the back transmitting itself through the car.
Good luck
I'm also suffering from the same problem. You'll be interested to know I have a Seat Toledo, so very similar.
I think I've pinpointed mine to one of the rear calipers intermittently sticking. My vibration doesn't happen all the time, but more so when hot. I'm going to clean them up and see if that sorts it. The rear calipers are a known issue for sticking on the Toledo.
As someone earliest suggested, don't dismiss the rear's because the steering wheel is shaking - it can transmit through the car.
I think I've pinpointed mine to one of the rear calipers intermittently sticking. My vibration doesn't happen all the time, but more so when hot. I'm going to clean them up and see if that sorts it. The rear calipers are a known issue for sticking on the Toledo.
As someone earliest suggested, don't dismiss the rear's because the steering wheel is shaking - it can transmit through the car.
Paul.B said:
200bhp - You may have 'Pick Up' where part of the pad surface sticks to the disc face. This can occur after one or two enthusiastic stops. Then every time you apply the brakes the pad catches on the pad material stuck to the disc surface.
In which case changing discs and pads would have removed the problem, but it didn't. Could be run out caused by e.g. bent hub, this is very easy to find just be clamping the disc to the hub and measuring run out with a DTI. A binding caliper (either piston(s) or sliders) can also cause cause bad vibration.
Mr2Mike said:
In which case changing discs and pads would have removed the problem, but it didn't.
Could be run out caused by e.g. bent hub, this is very easy to find just be clamping the disc to the hub and measuring run out with a DTI. A binding caliper (either piston(s) or sliders) can also cause cause bad vibration.
Ah. Missed the disc & pad change. Could be run out caused by e.g. bent hub, this is very easy to find just be clamping the disc to the hub and measuring run out with a DTI. A binding caliper (either piston(s) or sliders) can also cause cause bad vibration.
Paul.B said:
Mr2Mike said:
In which case changing discs and pads would have removed the problem, but it didn't.
Could be run out caused by e.g. bent hub, this is very easy to find just be clamping the disc to the hub and measuring run out with a DTI. A binding caliper (either piston(s) or sliders) can also cause cause bad vibration.
Ah. Missed the disc & pad change. Could be run out caused by e.g. bent hub, this is very easy to find just be clamping the disc to the hub and measuring run out with a DTI. A binding caliper (either piston(s) or sliders) can also cause cause bad vibration.
200bhp said:
Paul.B said:
Mr2Mike said:
In which case changing discs and pads would have removed the problem, but it didn't.
Could be run out caused by e.g. bent hub, this is very easy to find just be clamping the disc to the hub and measuring run out with a DTI. A binding caliper (either piston(s) or sliders) can also cause cause bad vibration.
Ah. Missed the disc & pad change. Could be run out caused by e.g. bent hub, this is very easy to find just be clamping the disc to the hub and measuring run out with a DTI. A binding caliper (either piston(s) or sliders) can also cause cause bad vibration.
In which case pad deposits on the discs could well be problem. A very coarse flap wheel on an electric drill would remove this fairly easily.
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