discs keep warping!
discs keep warping!
Author
Discussion

gcpeters

Original Poster:

1,002 posts

261 months

Wednesday 21st June 2006
quotequote all
had a brand new set of discs fitted

1000 miles one and warped - took back to peninsula they skimmed etc, all sorted, 600 miles warped again!

any ideas??? i have rang peninsula and they are going to take a look, faulty discs from the factory??

GP

DuncanM

7,460 posts

308 months

Wednesday 21st June 2006
quotequote all
gcpeters said:
had a brand new set of discs fitted

1000 miles one and warped - took back to peninsula they skimmed etc, all sorted, 600 miles warped again!

any ideas??? i have rang peninsula and they are going to take a look, faulty discs from the factory??

GP


Dude, Discs don't warp in my experience.

To clear the problem do the following:

Drive to 30mph and then do a smooth emeregency stop. Drive to 30mph and do an agressive emergency stop.

Repeat but with speeds of 60mph instead of 30mph.

You need to be very firm with the pedal and push through the vibration you're getting.

repeat the 60 mph bit until the vibrations go away.

This has always worked for me.

I will dig out the info I have on the myth of disc warp .

Duncan

DuncanM

7,460 posts

308 months

longbow

1,610 posts

264 months

Wednesday 21st June 2006
quotequote all
One of your callipers may be binding ever so slightly, and apart from heating the disc up more than normal, will cause it to dissipate that heat back through the pad surface when you stop causing it to warp. One the other hand a new disc can be prone to warp due to maunfacturing irregularities, just happens from time to time.

johnbear

1,568 posts

264 months

Wednesday 21st June 2006
quotequote all
Many think that warping doesn't exist, that it is a build up of residue from the brake pads on the discs.

The solution is the carefully remove the residue with light sanding. I tried this and it didn't work for me.

I then tried having the discs skimmed. That lasted all for two days.

I had the discs replaced at TVRPower in the end. Dom at Power thinks it's to do with the memory of casting. Years ago the casting would be left to stand for ages before machining, so they would settle first. These days that are machined shortly after casting and as a result some discs haven't stablised.

Even after a re-machining, the warped disc once hot will just warp in the direction it had previously.

I understand the solution is to bin the discs and get them to fit new one's. It's not going to kill them as they're about £240 plus vat for a front drilled set.

That my 2p anyway.

John

DuncanM

7,460 posts

308 months

Wednesday 21st June 2006
quotequote all
My method has never failed me!

What you're trying to get is an even distribution of pad material onto the surface of the disc rather than the hot spots which build up in town driving (hot pads pressed to disc at roundabouts etc).

Seriously woth a go and pretty cheap at £0 too .

Duncan

Steve_T

6,356 posts

301 months

Wednesday 21st June 2006
quotequote all
Are your disks are skimmed while attached to the hub? If not, this could explain the warping.

Steve.

johnbear

1,568 posts

264 months

Wednesday 21st June 2006
quotequote all
Many think that warping doesn't exist, that it is a build up of residue from the brake pads on the discs.

The solution is the carefully remove the residue with light sanding. I tried this and it didn't work for me.

I then tried having the discs skimmed. That lasted all for two days.

I had the discs replaced at TVRPower in the end. Dom at Power thinks it's to do with the memory of casting. Years ago the casting would be left to stand for ages before machining, so they would settle first. These days that are machined shortly after casting and as a result some discs haven't stablised.

Even after a re-machining, the warped disc once hot will just warp in the direction it had previously.

I understand the solution is to bin the discs and get them to fit new one's. It's not going to kill them as they're about £240 plus vat for a front drilled set.

That my 2p anyway.

John

headcase

2,389 posts

246 months

Wednesday 21st June 2006
quotequote all
Now thats the slowest echo ive ever heard, are we in a massive canyon?

big_treacle

1,727 posts

289 months

Wednesday 21st June 2006
quotequote all
headcase said:
Now thats the slowest echo ive ever heard, are we in a massive canyon?


hahaha that made me spill tea

nick cooper

139 posts

248 months

Thursday 22nd June 2006
quotequote all
As we are on the subject mine seem to be warped intermitentley? sometimes really bad and gets me thinking about a new set of discs then seem ok, think i'll try the free fix to see if it works, any ideas?

DuncanM

7,460 posts

308 months

Thursday 22nd June 2006
quotequote all
nick cooper said:
As we are on the subject mine seem to be warped intermitentley? sometimes really bad and gets me thinking about a new set of discs then seem ok, think i'll try the free fix to see if it works, any ideas?


Why not try my FOC method above?

dean_ratpac

1,582 posts

307 months

Thursday 22nd June 2006
quotequote all
when i get the chance i'll post some pics of cracked disks that i pulled off the rears.. it sounded like they were warped, as they were knocking the caliper.

SlvrCrb

1,180 posts

262 months

Thursday 22nd June 2006
quotequote all
DuncanM said:
nick cooper said:
As we are on the subject mine seem to be warped intermitentley? sometimes really bad and gets me thinking about a new set of discs then seem ok, think i'll try the free fix to see if it works, any ideas?


Why not try my FOC method above?


i use the foc method about every 3 months or so. never fails.

DuncanM

7,460 posts

308 months

Thursday 22nd June 2006
quotequote all
Thank God for that .

Thought I was going mad.

Seems some people want to throw money at the car instead!

Duncan

jesfirth

1,743 posts

271 months

Thursday 22nd June 2006
quotequote all
I put a brand new set of disks on last year and warped the fronts shortly after. When i had them skimmed the engineer pointed out that the pads were fractionally too large for the disks ie the pads overlapped the outer edge of the disk. as the pads wore it left a ridge on top the the pads which rubs on the top/outer edge of the disk causing it to overheat and warp. Apparently it was quite common in the mini race cars.

i had the disks skimmed and then I filed back the top edge of the pads and since then 1 track day and various sprints and they have been fine.

nick cooper

139 posts

248 months

Thursday 22nd June 2006
quotequote all
DuncanM said:


I used to work as a mechanic years ago in a ford dealership and we must have changed hundreds of discs and pads for brake judder after reading that i wonder how much money was wasted. Going to try this next time i get cerb out to play, if it works i'll be well chuffed as i'm getting a bit tired of throwing money at it, cheers for that one duncan. Will let you know the result.

DuncanM

7,460 posts

308 months

Thursday 22nd June 2006
quotequote all
Happy to help

Duncan

nick cooper

139 posts

248 months

Saturday 24th June 2006
quotequote all
Try'd the FOC method last night seems to work but had to really try to burn some material of the pads to stop the judder but all seemed well after so thats me . Cheers once again Duncan

DuncanM

7,460 posts

308 months

Sunday 25th June 2006
quotequote all
Excellent news, you do need to 'work' the brakes to bed them in but that's kinda the point as far as I'm concerned .



Duncan