Discs warped again

[glynnd]

Hi to all.
Forgive this thread and please no replies about using the search facility!
Had my leon fr 20vt almost a year.
When I bought the car it had new discs and pads fitted, car was showing 73k.
Within 7k dics were totally shot.
Replaced the discs and pads for Apec items which lasted no time at at all.
Replaced them for another Apec set as I returned them under warranty, pads replaced too.
They lasted no time at all either so returned them and got my money back.
Purchased VW economy discs and pagid vw pads from TPS and installed on 20th March thinking ok the other sets were not genuine and perhaps the 312 set up only likes genuine stuff?
Wrong! warped again, less than 3k.
So before I ask any questions or advice;
Yes they are bedded in properly I dont brake heavy unless some muppet makes me do it!
All hub faces cleaned up properly prior to fitting
Guide pins all free and clean.
Calipers clean, not binding and car pulls up in a straight line.
Thoughts?
I am thinking that its had accident damage and either a carrier or caliper has been damaged? All looks fine and the carriers look right when I installed the last set of discs.
Getting fed up now as you can all imagine!

 

[leoncupra2012]

Get it on a brake tester at an MOT place, see if its braking correctly and evenly on each corner?

If all is well can't think of anything else? My brother does a lot of stop start driving on and off the brakes hard and always manages to warp his discs but thats the way he drives.

 

[TllEWL]

Are you just getting vibration under braking ? (which leads you to think the discs are warped)

I (thought I'd) killed 3 sets of LCR discs on the Toledo, so rebuilt my Brembos, bought some very expensive 2-piece discs ...and still got the vibration you'd associate with warped discs

I don't know why they wouldn't do it from the moment you put them on, but someone on here had the same issue that they finally cured when they replaced the top-mounts !


The Toledo's been off the road since, so I've not replaced my top mounts (yet), but I sold the LCR discs on eBay - bit naughty - and never had any complaints ...so maybe they weren't warped afterall

 

[fahafiz]

i warped my discs once when i was driving through a puddle and braked - apprantly the disks were hot and braking in water caused them to warp (said the mechanic)

 

[Slimy]

I don't mean to sound negative, but could you describe your bedding in procedure? I remember one person having a similar issue and said he was bedding his brakes in properly, turned out his method of bedding in was completely wrong!

From memory, the easiest way to bed in brakes is;

1. Accelerate to 50-60mph.
2. Use MODERATE braking down to about 10mph. Not enough to engage ABS, but more than you might expect on new brakes.
3. Release the pads and let the brakes cool down evenly. Just drive at a decent speed for a minute or so, it doesn't take much.
4. Repeat three or four times until the brakes have gone through several heat cycles.

I've never had any luck with the way my dad told me, which was to pussyfoot around for the first 1000 miles. As soon as you use the brakes normally, they warp as they've never been warmed up.

 

[PSX]

I'd add a +1 to Slimy's comments there.. On my current (cheapy Mintex) pads it recommends in the instruction leaflet to brake gently for the first few hundred miles I think, but looking at the information I've read, it seems like a far better idea to do a 'heat cycle' as Slimy suggests and properly transfer a layer of pad material onto the discs. Without that even transfer of material, the different areas of the disc will heat up at different rates when first used in anger.

Thoughts?

Alex

 

[Muzza1742]

yeah i dont believe in the drive careful for the first few hundred miles stuff either. you've got to get some heat and grip on the pads at some point so you might as well do it in as controlled a way as you can as soon as you can

 

[Stokie]

I don't mean to sound negative, but could you describe your bedding in procedure? I remember one person having a similar issue and said he was bedding his brakes in properly, turned out his method of bedding in was completely wrong!

From memory, the easiest way to bed in brakes is;

1. Accelerate to 50-60mph.
2. Use MODERATE braking down to about 10mph. Not enough to engage ABS, but more than you might expect on new brakes.
3. Release the pads and let the brakes cool down evenly. Just drive at a decent speed for a minute or so, it doesn't take much.
4. Repeat three or four times until the brakes have gone through several heat cycles.

I've never had any luck with the way my dad told me, which was to pussyfoot around for the first 1000 miles. As soon as you use the brakes normally, they warp as they've never been warmed up.

Proper bedding in is easy, you just simply carry on using the brakes as normal, only difference is you brake abit ealier than you usually would for the first 250 mile, thats how ive always done it & works for me when i have new discs & pads

 

[Double-6s]

Do you leave your foot on the brakes when they're hot mate?

 

[glynnd]

I don't mean to sound negative, but could you describe your bedding in procedure? I remember one person having a similar issue and said he was bedding his brakes in properly, turned out his method of bedding in was completely wrong!

From memory, the easiest way to bed in brakes is;

1. Accelerate to 50-60mph.
2. Use MODERATE braking down to about 10mph. Not enough to engage ABS, but more than you might expect on new brakes.
3. Release the pads and let the brakes cool down evenly. Just drive at a decent speed for a minute or so, it doesn't take much.
4. Repeat three or four times until the brakes have gone through several heat cycles.

I've never had any luck with the way my dad told me, which was to pussyfoot around for the first 1000 miles. As soon as you use the brakes normally, they warp as they've never been warmed up.

Interesting theory but I worked in the motor trade for 15 years, had tens of brand new cars as demos, ran them to 6k ish then they got sold. Never ever had this problem and from new I had 5 corolla t sports and they all had THRASH from day one! I know my Leon is not a corolla but come on! Even my previous Leon with 288 set up had no issues when I fitted new discs, so I am stumped.

 

[glynnd]

Are you just getting vibration under braking ? (which leads you to think the discs are warped)

I (thought I'd) killed 3 sets of LCR discs on the Toledo, so rebuilt my Brembos, bought some very expensive 2-piece discs ...and still got the vibration you'd associate with warped discs

I don't know why they wouldn't do it from the moment you put them on, but someone on here had the same issue that they finally cured when they replaced the top-mounts !


The Toledo's been off the road since, so I've not replaced my top mounts (yet), but I sold the LCR discs on eBay - bit naughty - and never had any complaints ...so maybe they weren't warped afterall

Will check my top mounts, its just strange that each time I replace the discs for a short period the brakes are vibration free, so could almost certainly rule them out as the problem.

 

[Slimy]

Interesting theory but I worked in the motor trade for 15 years, had tens of brand new cars as demos, ran them to 6k ish then they got sold. Never ever had this problem and from new I had 5 corolla t sports and they all had THRASH from day one! I know my Leon is not a corolla but come on! Even my previous Leon with 288 set up had no issues when I fitted new discs, so I am stumped.

No worries mate, if you're happy with your bedding in then that's all good. I'll just remember never to buy a Corolla from you!

You did mention in your first post about possible accident damage, I'd say it's similar to what you mentioned about the top mounts in that if it was accident damage you'd feel it straightaway?

Another thing that could cause warped discs is the quality of the discs themselves, for example Halfords discs are not worth topping milk bottles and warp whilst in their cardboard boxes. I've not heard of Apec to be fair so I don't know what they're like, but even VW economy should have been fine.

Just one other thought, you've got 73k on the car, do you have a service history for it? Has it had an unusually high number of disc swaps during it's life?

 

[traumapat]

Driving style? if you stop after using the brakes hard the discs cool but the bit under the pads cools far slower hence warping.
If accident damaged caliper wouldnt the pads wear unevenly?

 

[Dannyh]

Ok well I bought my car with warped disk and then replaced them 3 months later I think they are slightly warped again, theory is the pads and disk gets super hot and when I stop the pad/disk area stays warmer for longer,

when I installed the disk / pads I noticed that the pads seem to be constantly on the disk and when driving with the window down I can hear a slight grinding coming as the disk rotates, I think I have a damaged seal on one of the pistons so when I release the brake it still stays slightly applied, I believe this has also led to my bearings going because it has boiled the fluid in the bearings, hopefully the pad will wear and it will stop, if it gets worse I might buy new disk/pads and before installation wear the new pads down a little so that they are not constantly touching the disk

This is only on my passenger side caliper thought the driver’s side is fine

 

[nally270lb.TQE]

I ha dthis on my Fto GR and it was siezed calipers on both rear sides. My pads just kept constantly on the disc warping them. It was not fun to brake, savage vibration

 

[Slimy]

Ok well I bought my car with warped disk and then replaced them 3 months later I think they are slightly warped again, theory is the pads and disk gets super hot and when I stop the pad/disk area stays warmer for longer,

when I installed the disk / pads I noticed that the pads seem to be constantly on the disk and when driving with the window down I can hear a slight grinding coming as the disk rotates, I think I have a damaged seal on one of the pistons so when I release the brake it still stays slightly applied, I believe this has also led to my bearings going because it has boiled the fluid in the bearings, hopefully the pad will wear and it will stop, if it gets worse I might buy new disk/pads and before installation wear the new pads down a little so that they are not constantly touching the disk

This is only on my passenger side caliper thought the driver’s side is fine

The problem you'll find is that as the pads wear down, the piston moves out and gets stuck again, so the pad will always be in contact with the pad. You should really sort the piston out before you fry another set of discs and pads.

 

[Dannyh]

The problem you'll find is that as the pads wear down, the piston moves out and gets stuck again, so the pad will always be in contact with the pad. You should really sort the piston out before you fry another set of discs and pads.

Thanks, anty idea where i can get replacement pistons and seals from for the brembo caliper?

 

[glynnd]

Driving style? if you stop after using the brakes hard the discs cool but the bit under the pads cools far slower hence warping.
If accident damaged caliper wouldnt the pads wear unevenly?

Its not my driving style, I would only have myself to blame and easy to sort the issue!
I have done 13k on my front tyres with 5mm still left, most of my mileage is motorway.
35k per year!

 

[Dan1720v]

It sounds like pad deposit, I found this using cheap pads, put in a set of something like ds2500's and it'll clean up the surface of the discs aswell as being a massive improvement.

 

[traumapat]

Its not my driving style, I would only have myself to blame and easy to sort the issue!
I have done 13k on my front tyres with 5mm still left, most of my mileage is motorway.
35k per year!

Its not about blame or fault, its simply that pulling up after braking hard will cause the brakes to cool unevenly and warp. Youd only need to do this once. Ive no idea how you drive hence the question mark. Several members have had warping due to the above so its worth being aware.