Talk Morgan Forums Morgan Sports Cars Maintenance & Servicing Front Disc shudder

I have noticed under reasonably hard braking (Not emergency) from about 140kmh that I get a shudder through the front discs on my +4.

I have not investigated this fully yet and it does not seem to do it on normal around town driving.

Does anyone have an idea what I should be looking for or what may be the cause. The car has only done 11k.

First thing is to check the discs for a pad imprint. When left standing the area under the pads will react differently to the exposed disc. It may stay shinier but I've also seen pitting in the pad imprint. Slight variation could be enough for a shudder.
It might also be wheel balance if that's slightly out.

Try a few hard stops - sometimes that will settle things down.

I agree that Dave's solution are more likely to resolve the issue, but when you have exhausted those , try checking the front discs for run out , I think the "normal tolerance is +/- 4 thou , anything more than this will give you severe judder (but it is likely to happen at all speeds) so unlikely to be the culprit in your case.

Thanks for the replies, the car doesn't sit for more than a week, and is garaged the whole time. I think wheel balance would be noticed at lower speeds as well.
I was thinking of a minor warp, that would probably not be over noticeable at low pressure but harder application and faster rotation would make it increase.

Are you sure it's at the front?
I thought I had some minor run out on mine which got worse with increased brake use (think lots of hilly/mountainous type terrain). Turns out to be a slightly warped drum which is only noticeable on a brake tester when the brakes are cold...

My Aero 8 had the same problem some time ago, it was as Dave suggested....pad imprints caused by washing the car and putting it away with wet brakes, I now always run round the block after washing to warm the brakes and disperce any moisture from the pads.

I had them "cured" by skimming, in the Aero's case much cheaper than new discs!!
Ian

Re Dave's solution, I had the same problem the other day. The car hadn't been out for a couple of weeks so the initial braking was some what butt clenching but with a few hard applications all is well.
It just goes to prove that you must use the car as often as possible.