[Mk2] [Generic] front discs keep warping

[coup27]

Hi,

I have an issue where the front discs keep warping. I had the discs and pads changed on the front because the old ones were gonners and a month or two later I started to feel a vibration through the steering wheel when braking from 40mph and above. This vibration started small but eventually became quite severe. I thought this might just be a bad set of discs so I had them replaced (FOC) along with new pads and the problem went away.

A few months later the problem then came back. The mechanic I use wasn't available this time so I did it myself. I have a friend who works for a motor factors and can get me cheap parts so I went the whole 9 yards and fitted new callipers, discs and pads on both sides. I also checked the state of the slider pins. One side was fine but the other side were dry as a bone and rusted through because the boots/seals had broken down. I thought this might be the problem so I got 2 new pins and seals from Toyota and lubed them with silicone grease and fitted it all back together. Once again the vibration had gone.

A few months later and it's back again!

I am really at my wits end with it now. Naturally there is quite a bit of play in my steering rack, could that somehow be causing this?

Any help is much appreciated.

[C35Rob]

Are they actually warped though? Have you checked the discs for runout? It may well be pad material deposition on the discs, which is the case probably 90% of the time people get vibration through the wheel and immediately think theyre warped.

What discs/pads have you used (i.e brand) have you followed the bedding in procedure properly? Do you sit a standstill with your foot on the brakes? Especially after hot/high speed stops?

[ashley]

http://www.mossmotoring.com/warped-brak ... the-facts/

[bobhatton]

I have a friend who works for a motor factors and can get me cheap parts

That is not what you need on brakes

[raptor95GTS]

I don't know if the cheaper discs are the same source of blanks but miss finishing processes or whether they are cheaper materials and thus cheaper to get / sell on but cheap discs really don't behave like proper OEM quality discs. As Bob says, cheap aint desirable on braking components (unless of course you're getting OEM or upgraded known quality parts cheaper!)

[Slarty]

Are they actually warped though? Have you checked the discs for runout?

Very valid point. First you need to raise and support the car. Remove the road wheel and then use the wheel nuts to tighten the disc to the hub. Use a DTI (dial test indicator) on the outer most section of the disc and slowly rotate it. As it hits the highest value on the clock, set it to zero and then rotate it until it hits the lowest value. That'll give you the amount of runout that you have (or have not lol) on the disc.

It could well be something else though, top mounts for instance. If you find no - minimal runout on the discs you know you need to start looking elsewhere

[SonicSW20]

The fact that the problem keeps coming back after a couple months suggests that you aren't bedding in the brakes correctly, or at all. If you do not bed them in correctly, you'll get an uneven transfer layer on the discs that will get worse with use as it builds unevenly. This will cause vibration.

[acf8181]

The fact that the problem keeps coming back after a couple months suggests that you aren't bedding in the brakes correctly, or at all. If you do not bed them in correctly, you'll get an uneven transfer layer on the discs that will get worse with use as it builds unevenly. This will cause vibration.

...this!

[coup27]

Firstly, thank you for all the replies.

I was a bit misleading when I said I used cheap parts. My friend got me parts at manager's special prices. The first discs were Blueprint, the other 2 sets were Pagid. I can't remember what make the first pads were but the rest have all been Pagid. I don't sit with my foot on the brake and use the handbrake as much as possible.

I am not an expert on this subject so I was being guided by so called experts. I never got the discs checked for run out because as soon as they were changed the problem was cured so for the uninitiated this pointed to warped discs. I was advised to change the callipers after the first 2 sets "warped" because an expert suspected the calliper wasn't releasing the disc properly causing it to heat up and warp.

I have read that "warped brake discs - the facts" link and found it very informative. I have not been bedding in the brakes as indicated on that link. I was always lead to believe all you needed to do was to drive gently for a 20 miles or so and gradually build up the braking to normal.

What I will say in counter to that procedure is whilst it may be correct to bed them in like that, the vast majority of people don't. If you have D&P's done at a dealer or garage I doubt very much they do that procedure for you and just give you the keys and tell you to watch your brakes for a bit so there must be some leeway on this procedure or vibrations would be happening to everybody.

Either way, I will follow this procedure in the future. I have actually sold the car now so I can't try this out to see if it was the cause.

[daz364]

Hi I had this very same issue with warping disc fitted a set of drilled and grooved that just resolved it never looked back

[asdrewq]

Did you clean the hub face thoroughly of all corrosion & ensure it was smooth with emery paper prior to fitting the discs?