warped discs?

[PEGE63]

Fitted new discs and pads earlier this year (Brembo) after having bad vibrations during breaking. Initially fine but have slight issues again during high speed braking.
Measured discs as follows at outer edge.
LF out by 9/100
LR out by 20/100
RF out by 15/100
RR ut by 10/100
Can not work out if this is within acceptable tolerances or not. Discs are under warranty but do not want to return and then find they will not accept them as faulty. Chicken in an egg...

[Kev0607]

Originally Posted by PEGE63

Fitted new discs and pads earlier this year (Brembo) after having bad vibrations during breaking. Initially fine but have slight issues again during high speed braking.
Measured discs as follows at outer edge.
LF out by 9/100
LR out by 20/100
RF out by 15/100
RR ut by 10/100
Can not work out if this is within acceptable tolerances or not. Discs are under warranty but do not want to return and then find they will not accept them as faulty. Chicken in an egg...

Are you getting vibration as you brake?

Where did you get these Brembo discs from? I know Euro Car Parts do Brembo, but I’m not convinced that they’re actually the real deal.

[100K+]

Im assuming the measurement are “ 100ths out of true”. We’re the hubs spotless before fitting discs? Back in the day my indi garage mate had to spend several minutes with a plastic brush in a drill cleaning the hubs before fitting new discs to Ford fiestas. If not the new discs would shudder.
Also we’re the hubs spot on?

Cheers Bob

[PEGE63]

Got gear from AUTODOC and was branded correctly so presume kosher.
Cleaning the surfaces, that is a very good point, will investigate that asap.

[Kev0607]

Originally Posted by 100K+

Im assuming the measurement are “ 100ths out of true”. We’re the hubs spotless before fitting discs? Back in the day my indi garage mate had to spend several minutes with a plastic brush in a drill cleaning the hubs before fitting new discs to Ford fiestas. If not the new discs would shudder.
Also we’re the hubs spot on?

Cheers Bob

That’s what should be done regardless on any car that has disc brakes. If the rust/debris is really bad, it may take several minutes. Normally, a good dose of brake cleaner & a good scrub of a wire brush works too.

You’re right though. A small bit of rust or debris on the hub can cause a shudder. Just slapping discs on without cleaning the hub isn’t a great idea, but hey… it happens. Its like putting the pads on without any lubrication & then wondering why they squeak!

[Clan]

Originally Posted by PEGE63

Fitted new discs and pads earlier this year (Brembo) after having bad vibrations during breaking. Initially fine but have slight issues again during high speed braking.
Measured discs as follows at outer edge.
LF out by 9/100
LR out by 20/100
RF out by 15/100
RR ut by 10/100
Can not work out if this is within acceptable tolerances or not. Discs are under warranty but do not want to return and then find they will not accept them as faulty. Chicken in an egg...

apart from what has been said above , have you torqued up the wheel bolts up to 140 NM * ? That means all 5 INCLUDING the locking nut ? There was a volvo bulletin about this about 5 years ago , people were not tightening the locking bolt properly so uneven stresses in the disc eventually warping it .


* assuming your wheel bolts are the v70 etc after 2000

[Kev0607]

Another point I’d like to make is I’ve found aftermarket/non-genuine discs to be junk lately.

I fitted Pagid’s on my S80 from Euro Car Parts, they were warped within two years… no heavy braking & everything was done properly like cleaning the hubs etc. I’d never use them again.

I’ve not had an issue since fitting genuine Volvo discs (Made by ATE). The car brakes much better with originals than with the Pagid’s I think (they feel sharper).

[Turbodave]

I'd also vouch for Volvo OEM parts, which if sourced via the likes of "Volvotradeparts" aka "Mill Garage Volvo in Newcastle" on eBay, they're not actually ruinously more expensive then many "decent" aftermarket brands... and if the cheaper brands are half the price, there's probably a reason for that.

My XC70 had Volvo OEM front discs and pads fitted before I bought it, the seller being resolute in the fact he wouldn't fit anything but and 18 months and about 16,000 miles down the line, they are fine and remain corrosion free aside for the usual discolouration round the vents.

If you don't want to go down that route, then Apec have always served me well for the money. The likes of Brembo / Pagid etc... I'm just not convinced they live up to the name / old reputations anymore and seem to have slipped into "cheaper for a reason" territory.

[PEGE63]

Thanks for all comments, will check into all asap n report back.

[MDS40]

Another point I’d like to make is I’ve found aftermarket/non-genuine discs to be junk lately.

100% Agree with that comment.