AP Brake Disc Replacement

[Mike Molloy]

I noticed I was getting quite a bad vibration through the steering at Silverstone yesterday. We had a look at the wheels for any foreign bodies, but they seemed OK. The MB wheel rims do have quite noticeable "run out" at the rim, but I suspect this is down to the multi-part construction..

With the wheels off I tried rotating the hubs and found that one was binding quite badly. It would rotate freely through 180 degrees and then "stick". I have recently replaced the wheel bearings in this hub, but the only way I can see this effect happening is if the disc is warped. Strangely the "wheel wobble" was under power. Braking felt quite smooth

 

The brakes are Caterham/AP 4-pots with vented discs (2000MY).

Are these prone to warping?

Any tips on how to diagnose/rectify?

 

If the disc is shot, what is the part no. and ballpark price for a replacement?

 

Thanks,

Mike.

[Shaun_E]

just some thoughts:

Is the wheel bearing seated properly? It is pretty unlikely that your discs have warped (read this for some background). You can check the run out on the discs as it is not impossible for them to warp but it would likely be due to wear or material failure rather than heat. I'd also get the wheel balanced - you might have lost a weight.

All IMHO - I haven't changed a bearing before but in reading the instructions when I was going to do one of mine, it seems you could potentially not get it seated perfectly straight.

 

Yellow SL #32

[Paul McKenzie]

The fronts on my mates' SLR warped. He had them skimmed and they were fine.

 

Paul

[david nelson]

same problem and am either going to get them skimmed or get some garnet paper and have a go at rubbing them down. cc price £128 each + vat

 

Can anyone tell me if I will need to replace my pads if the discs have been skimmed or rubbed down.

 

 

thanks

 

David

[SLR No.77]

Yes - if you have the disc skimmed the surface will be as a new disc - therefore you must fit new pads to avoid damage to the new surface from a set of worn ones. Don't attempt to rub them down - seek out a machine shop that does break discs.

 

Stu.

[Paul McKenzie]

I don't often moan about the price of Caterham parts since they're specialist low volume components..but the price of the vented discs is outrageous . I just bought some similarly sized vented discs for the wife's Polo...£27.51 inc. VAT

 

Paul

[SLR No.77]

There were a number of s/h vented discs advertised a year or so ago - so i decided to check the price of the calipers with Caterham - a pair of calipers is virtually the same price as the uprated brake kit! Caterham's comment at the time was that the kit is therefore exceptional value - I'm sure they make a good profit on the parts in the kit (and I support them in doing so), but it's difficult to justify the outrageous prices of the individual components

 

Stu.

[lrem]

Fluke Motorsport advertise a range of lightweight discs: here - might be worth giving them a try?

 

I guess they must also sell suitable ones for the 4-pot APs, since Fluke also advertise Pagid pads for "Caterham AP upgrade front".