[Tannaton]

Originally Posted by XC90Mk1

Thank you to all the comments above! My initial thoughts were that the brakes had only had pads. I was informed by Volvo in 2018 when I purchased (all new front brakes) and working on the premise that discs last 2 times as long as pads (finger in the air), and given the last pads had done 60k plus 5k (replaced them due to sequencing slider pins) that the original discs were in place.

However… interestingly I could see damage to the rear braking surface. I can tell with fingernail and visuals it’s considerably in excess of 1mm wear (Clans assertion that most Volvo discs allow 1mm earthed side). Clan makes a very interesting point, because not only did the front look visually ok (Bernie red at 1.13mm wear), but also the disk had stamped on it minimum thickness 27mm and mine was 28mm.

what I can conclude, is that the discs WERE fitted in 2018 as the date code inside said 18. The pads and discs seem to have alasted approximately 60,000 miles.

Now, I was asitonished to get 60k from a pit of pads, I thought it quite amazing!
But I am a little miffed at getting 60k from a pair of discs….

I have found from removing them that the wear is very disproportionately on the rear of the disc (which makes sense as that’s the piston side.

So, lesson of the day here… don’t Vernier measure them and assume all ok as mine verniered at 28mm against mum thickness of 27mm.
Don’t assume that because you have minimul wear on front face that rear is ok.

Do make sure you get properly under the vehicle where you can see the gap in the back plate and inspect. Mine were visually bad on the rear and I would have noted.

I replaced the discs. I think the pads had about 5,000 miles on them and whilst they looked very meaty the rear of the disc have worn in a concave fashion so I reluctantly fitted the new pads.

I did also replace the caliper bracket bolts. And I must say to anyone doing this REPLACE carrier bracket bolts!!! The bolts are torqued to either 140Nm and 60 degrees (yaynes manual) or 200Nm. I did torque them to 200Nm as that’s the Volvo instruction and I felt the bolts bed in and twist so they clearly go through a lot.

Getting them off was a nightmare so do best that in mind. I broke out the 1600nm impact wrench and it did not shift them!!! It simply say there with the socket getting burning hot.

I ended up using half inch breaker bar with 2 foot scaffold pole. Those who know me will know that is absolutly not my style, nor is it my recommendation, but getting beach bolt off from the caliper carrier bracket was very hard work so needs to be born in mind in future!

Thanks all!

............has it sorted the problem though?