V70R eating brake discs - why?

[MATTAL]

Help, anyone, please!
My beloved green meanie (2005 MY with no mods and stock throughout) has developed an appetite for OEM Volvo brake discs, 4 at a time! I have had, with local dealers service managers assistance and "forgetful" and helpful approach to invoicing, some 5 sets in the last 14 months!
They last 2-4 weeks on careful breaking in (no pun intended) and then when back to normal driving (fast A-roads and M-ways but not >75mph as company only pays me govt. approved mileage!), they only last about 6 more weeks before the dreaded thrumming starts every time I hit the middle pedal - it's got to the point where I prefer to use the gears to brake in case I lock it and risk a spin out, yep, they get THAT bad!

Last new set warped after 13 weeks, so we skimmed them, all off the car, at a rally engineers shop. They were then fine for 8 weeks but now, 2 are partially warped again and 1 is needing skimmed or replaced again!!

Anyone, anywhere, any ideas or suggestions - this is the 2nd top-spec Volvo that has done this to me in a row (last was my 850 T5-R) and I am seriously looking at bailing from the "Swedish way of life" in the near future if I can't get a fix on this. they just don't seem capable of dealing with the weight/speed combination.

Please, please, any ideas folks........................

Ta,
MATT

[v70rade]

It's funny that you should mention it; but I'm in exactly the same boat with my 2000MY V70R - I'm afraid I can't offer a solution though, as my car has eaten the following front discs in order (All 302mm): -

1 / Genuine Volvo - Fairly new when I bought the car and warped within 5k miles
2 / EBC Power Discs - Lasted approx 8k miles before warping.
3 / Delphi Lockheed - Lasted 2k miles before warping so badly that at 40mph, touching the brake pedal nearly ripped the steering wheel out of your hands!
4 / Now another set of Genuine Volvo!! - Lasted about 5k miles and that was being really gentle with them.

I very rarely ever brake hard and have resorted to using the lower gear selections of the auto box to assist with braking to save the discs.

After the second set of discs, I completely stripped, cleaned and overhauled all four callipers and gave the whole brake system a thorough going over (just in case I had seized callipers or the like), but still the problem persists.

I know it's not my driving style as I've only done 10% of my entire life's driving in my R, but I have never warped a disc on any car before, even when I drove one of my 440T's like I'd stolen it for three years!!

The only thing that has crossed my mind with these bigger diameter discs (302mm on mine and probably 330mm on yours?) is that the inner 'bell' diameter is still the same size as for the less powerful models with smaller discs. To my mind, this would mean a greater 'unsupported' area to flex when hot on the larger diameter discs? - just a thought.

The fact that it happens to all 'makes' of disc supports the issue being a design 'quirk' with the disc dimensions.

BTW, my record was 3mm lateral deflection across a 302mm disc.

Sorry I don't have the answer, but at least you know that you're not on your own!

Ade.

[Liddo]

Its gotta be a sticky caliper??? Its sounds like its generating too much heat in the disc?? Im no expert, but it could be the problem.

Also, do you use jet washes?? straight after a long trip where the discs have got hot?? Cooling down the discs very quickly may also warp them??

Again, im no expert, its just my idea's



Hope ya get it sorted

[JelT5]

This makes interesting reading; I'm not saying you guys aren't bedding the pads in properly btw!

http://www.stoptech.com/tech_info/wp_warped_brakedisk.shtml

[wegal]

Autos can warp disks for fun, but thats a driver issue rather than a fault of the disks, when you stop at a set of lights or after a motorway run DONT hold the car on the foot brake.. use the hand brake. The hot pads sit against the disk and that area doesnt cool as fast as the rest and they start to warp... do that 50 or 100 or 500 times and they are buggered !

Warped disks is simply because they are getting too hot then not cooling evenly, no other reason, they can warp when they get thin as the heat dissapation is too fast on exposed area's but not where the pads sit. Why they should overheat so badly when new I dont know, try taking the splash guards off the back of the disks to increase the cooling / airflow.

Are you using volvo pads ? race pads may induce more heat into the disk as they are harder compound.

Just a few ideas to consider. Good luck with it

[mds]

Both our P2 V70's have been upgraded to the Volvo police spec discs (320mm) and pads and neither car has shown any signs of excessive wear or vibration 80k and 128k respectively.
The only Volvo I have ever had an issue with was a P1 V70 and that turned out to be a sticking calliper.
So I concur with Liddo, something is sticking and causing overheating on one side of the disc = warp.
If it was a common problem there would be an avalanche of posts?

[Liddo]

To add, one way to check IF its a sticky caliper is to go for a good, long, fast run, and then pull over and feel your alloys. If any are warm/hot to the touch, that'll be the one thats sticking. The heat soaks through the disk and hub and onto your wheels (if its bad enough)

[LeeT5]

Help, anyone, please!
My beloved green meanie (2005 MY with no mods and stock throughout) has developed an appetite for OEM Volvo brake discs, 4 at a time! I have had, with local dealers service managers assistance and "forgetful" and helpful approach to invoicing, some 5 sets in the last 14 months!
They last 2-4 weeks on careful breaking in (no pun intended) and then when back to normal driving (fast A-roads and M-ways but not >75mph as company only pays me govt. approved mileage!), they only last about 6 more weeks before the dreaded thrumming starts every time I hit the middle pedal - it's got to the point where I prefer to use the gears to brake in case I lock it and risk a spin out, yep, they get THAT bad!

Last new set warped after 13 weeks, so we skimmed them, all off the car, at a rally engineers shop. They were then fine for 8 weeks but now, 2 are partially warped again and 1 is needing skimmed or replaced again!!

Anyone, anywhere, any ideas or suggestions - this is the 2nd top-spec Volvo that has done this to me in a row (last was my 850 T5-R) and I am seriously looking at bailing from the "Swedish way of life" in the near future if I can't get a fix on this. they just don't seem capable of dealing with the weight/speed combination.

Please, please, any ideas folks........................

Ta,
MATT

I will keep it short and to the point:

Firstly...removing the discs from the car and having them skimmed is not good practise. The whole reason for skimming discs is to remove any raised spots and ensure the disc surface is totally flat across the entire surface. As soon as you bolt your disc to the hub you will immediately have disc run out, because the hub is NOT machined flat to such high tolerance as the newly skimmed disc. Therefore, to elliminate this problem you must skim the discs whilst they are fitted to the vehicle. There are a few places that provide this sort of service and usually costs about £50 per corner.

Secondly...the problem you have is NOT your discs. I have oe 330mm discs and pads all round on my R and i do not eat discs or pads. I am certain the problem you have relates to a partially seized caliper or a worn wheel bearing or possibly even a knackered CV joint. It cannot be anything else my friend.

Just because someone else has the same symptoms does not mean it is normal. They obviously have a fault with their car too. Common problems are normally the calipers. First place to look on the V70R/S60R 2003> is the calipers. I bet any money when you remove the pads and check the little steel plate that that guides the pads, you will find it is corroded underneath. The alloy corrodes and swells where the torques screw fits. Causes the pad/pads to bind and not free off the disc.

Only way of curing this problem without buying new calipers is to gently grind the ends of the pad so that it slides in and out of the caliper guide without sticking. Or pop down Volvo and buy yourself a new caliper...there only about £400 each! i filed the ends of my front pads and have not have a problem in 9 months. Brakes work perfect and no squeal.

Good luck.

[MATTAL]

Big thanks to all who have replied, spesh Lee's last one, which I have printed out along with the others to go through with my good frined the Volvo service manager.
I'll keep you all advised of progress (skimming off car/on car are both possible for me and having done the former via rally friends contacts, going to do the latter next but the caliper suggestion from Lee is another valid and soon to be done point!).
Cheers all - here's hoping I can stay with the original Swedish mafia gang at the end of it all.
Thanks for now!