Brake disc issues.

[Dolomitejohn]

Hi all. Anyone purchased new standard brake discs from our usuall suppliers that when fitted cause brake judder which can be felt through the steering, brake pedal and front end in general. They come packaged in a green box with AJ Auto International marked all over?
Just wondering?
Cheers all.
John

[triumphdolomiteuk]

It's not unheard of to get brake judder caused by uneven disks. A colleague had new disks (rather expensive ones) fitted to his Evo and couldn't figure out why they were causing judder. The solution was to have the disks very lightly skimmed. It only takes a tiny amount of warp to cause a lot of judder. Now the truth is that if you're spending £300+ on a pair of new disks, you would expect them to to be perfect straight out of the box and not to have to faff about getting them skimmed.
I'd return your disks to the supplier and get them to refund or replace with a pair which aren't warped.

[GrahamFountain]

Yes, on the TR7 Sprint fitted with TR8 calipers. I got disks from a gRimmer supplier that had so much runout, they had to be skimmed and re-fitted.

Graham

[cleverusername]

It's not unheard of to get brake judder caused by uneven disks. A colleague had new disks (rather expensive ones) fitted to his Evo and couldn't figure out why they were causing judder. The solution was to have the disks very lightly skimmed. It only takes a tiny amount of warp to cause a lot of judder. Now the truth is that if you're spending £300+ on a pair of new disks, you would expect them to to be perfect straight out of the box and not to have to faff about getting them skimmed.
I'd return your disks to the supplier and get them to refund or replace with a pair which aren't warped.

More likely they were incorrectly fitted, hubs not properly cleaned.

[xvivalve]

The reason I started sourcing parts from first principles where I can is a pair of brake discs purchased from a major Triumph specialist in the mid 1990s. I spent a Saturday morning fitting them and new bearings to what was my daily driver that I needed for work on the Monday. Fortunately, before refitting the road wheel, I span the disc, and to my horror witnessed that the disc was visibly eccentric to the hub....and then spent the afternoon refitting my old discs. The supplier said they would send out a replacement pair upon receipt of the alleged defective items, I sourced NOS instead and eventually received a refund after significant 'discussion'.

I expect they still have stock...

[GrahamFountain]

It's not unheard of to get brake judder caused by uneven disks. A colleague had new disks (rather expensive ones) fitted to his Evo and couldn't figure out why they were causing judder. The solution was to have the disks very lightly skimmed. It only takes a tiny amount of warp to cause a lot of judder. Now the truth is that if you're spending £300+ on a pair of new disks, you would expect them to to be perfect straight out of the box and not to have to faff about getting them skimmed.
I'd return your disks to the supplier and get them to refund or replace with a pair which aren't warped.

More likely they were incorrectly fitted, hubs not properly cleaned.

Don't know. The one's I hat that problem with had a measurable variation in thickness, as though the faces had been machined separately, with the disk turned round between - that was the suggestion from the guy who measured them, Nick Dixon at MND Motorsport. I remember he was appalled at how bad they were. But, at the time, in the 1980s, it was cheaper to skim them than buy from a more reputable factor.

Graham

[Dolomitejohn]

They are def fitted correctly. All surfaces clean and rust free. Even tried a new hub, stub axle and bearings, (which were going to be fitted at a later date). Still no better. Tried rotating discs on the hub. Just fitted the replacement set they sent. Run out better on one side but still 0.2mm on the other side. Test drive shortly...... If no better will kick up a stink and prob get them skimmed.....

[tonybsa]

0.2mm is too much.You want between 0.1 and 0.15.Any less and the pads wont return properly.

[cliftyhanger]

I thought highend builds skimmed the discs on the car? There is a bit of kit for doing it, and I guess not massively expensive?
But yes, should not be required on new discs, only after proper abuse.