Talk Morgan Forums Morgan Sports Cars Maintenance & Servicing Brake Judder

I'd recommend getting your present disks skimmed.
Don't know why, but this brake judder seems to be a common problem with Morgan disks after 10 - 20 thousand miles. Have a set that have started this juddering skimmed and you'll get a lot of miles out of them before they eventually need replacing...

Hugo

As you have replaced both discs and pads, this may be worth considering.

I had the same on my +8, I investigated very carefully and the conclusion I came to was it was a sticking piston on one calliper.

To check, jack the car up on level ground, put stands under chassis and then remove front wheels. Get a solid metal object and position next to the disc, fix a sharp pointed metal object to it (like a long nail) so that it is just touching the disc near the outer edge. Slowly rotate the disc and watch/listen for any run out of the disc, you can expect a few thousands of and inch, check both sides of the disc. Repeat for both discs. If you have minimal run out then it is unlikely to be the discs causing the issue. I discussed this issue with Peter Mulberry and the callipers on earlier cars can distort and cause one piston to stick and then you get uneven pad pressure causing the judder under low to medium pressure. If you do not get the judder if you brake hard then you are probably force freeing the sticking piston when so doing. I do not know it the later callipers fitted to Morgans are prone to this or not.

If you do not do many miles in the car then with it standing around one piston may be corroding and thus sticking. You may need to remove the calipers and inspect the pistons and barrels, or get someone to do this for you if you are confident in the discs.

With mine I replaced the callipers, and problem was solved, did this as my issue was due to distortion of the calliper body.

I hope this helps, or gives you some ideas of what to look for.

Adrian,
true it could be a sticky piston but if both discs and pads are changed why does it appear now? I guess maybe pushing the pistons back for new pads.

Worth checking as you say.

Try to find what other car the discs are used on, and buy direct from a motor factor. They might be able to order direct from your reg no.

Yes I had exactly the same issues, which makes me suspect this is the problem here. If the discs check out on the run out check I would be even more convinced that a sticky piston was that cause. Remember that the old pads would have work to a particular shape (wedging) which may have been masking the problem, then you fit new pads and disks and then have the judders with low brake pressure.

As the front discs are very nearly an interference fit on the locating spigot on the rear of the hub, you probably have a small speck of something trapped between the disc mounting face and the hub. Ive seen it happen on a few cars where the mounting face was not cleaned properly prior to fitting new discs and it caused a lot of runout and judder.

Incidentally the discs that we sell, are actually reground second hand ones. As the disc is unique to Morgan, and they are not heat treated after machining, new discs can warp the first time they are used in anger (we see it a lot on the Challenge cars). However, by regrinding a used disc which has been through some heat cycles we find that they don't warp again

Simon @ Mulfab

I had the discs skimmed on my aero 8 due to brake judder, the Dealer I use for servicing etc asked me if I wash my car then put it away in the garage.....I did!!...
His advise is after washing drive round the block using the brakes to dry them out otherwise the pads sit on the inner side of the discs, allow it to rust slightly and leave a shadow where they had touched the disc causing shudder, I now religiously nip round the block and have had no more trouble

Thanks everyone for your advice, i will let you know what i find.

After ca. 19.000km road use only, the judder of the brakes on my 2014 4/4 was way too much. My dealer/garage changed the disks and told me about the same as described above. He fitted heat treated disks and since that the braking is very smooth. Until now I did not enough miles to tell about the quality on the long run.

Also make sure you chamfer the pads. Should be done on 1st service & kept an eye on. (Pad overlaps inner edge of disc slightly)