Rear drivers side wheel - extremely hot

[sunnyvic]

Have been scrolling through your forum and its nice to see so much knowkedge being passed on to other owners,car to mod for me but i have been enjoying reading..regards sunnyvic

[NCS XC90]

Hi all,
Just to close this topic, new caliper came today. Fitted and changed pads at same time. No problems bleeding the system and all back together. Took no more than an hour. Went for a test drive and brakes as it should and no heat build up anymore. Might have got rid of the drowning noise as well but that might just be wishful thinking.
Again thanks for all
Neil

[greenfingers]

When my 54 plate had exactly the same symptoms (rear n/s disc getting hot and also the same almost unnoticeable resonance), Kwik-fit did a free brake system check. They told me that the caliper was fine, but I needed new rear discs and pads at a cost of 264 quid. I pointed out that the discs were less than 10,000 miles old, but they insisted they were scored and would have to be replaced. Needless to say, I left in a hurry and decided to check for myself.

Back home, after taking the wheel, caliper and disc off, it was clear that the pads had been binding, because the corroded outer edge of the disc was black with oxidisation, however the disc was not worn or scored. The parking brake drum and shoes showed no signs of wear. I pushed the piston back and forth in the caliper a few times, brushed the rust off the carrier, cleaned and greased the slider pins and then reassembled everything.

All seemed fine, but then a couple of days later the problem reoccurred. The constant friction had caused some wear to the pads, so this time I fitted new ones, thinking that if the problem was to do with the caliper, then at least the piston would then be set further back inside which might (wishful thinking) result in it not sticking.

Alas, no joy, although the symptoms were now less severe. I was convinced it was the piston getting stuck in the caliper, so I removed the rubber gaiter and pushed the piston out as far as I dared without it popping out. The rubber gaiter itself was intact, but it had not been fitted correctly all the way around the piston housing and it's internal metal retainer ring was totally rusted. There were also some faint wear marks on the piston, but these polished out quite easily. There is a small internal chamfer in the front of the piston housing, which I suspect could trap rust or debris and then prevent the piston from returning correctly. I pushed the piston in and out a number of times, rotating, greasing and cleaning it each time. Eventually, it moved smoothly without jarring, so I reassembled with plenty of grease and now the brakes work fine.

The problem is that I know that rubber gaiter is not keeping the elements out and it is only a matter of time until the symptoms reappear. There is a thread somewhere on here where someone managed to get a caliper repair kit. I have searched the Web and Fleabay, but cannot find one for the XC90. Surely, this gaiter must be fitted on another type of vehicle - does anyone know? Volvo want around 300 quid for a recon caliper, but of course they can be had for less than that.

Please someone save me from a bodge fix!

[keithjeb]

Job jobbed
http://www.brakepartssuperstore.org....uk/d13138.html

[greenfingers]

Thanks Keithjeb - that's exactly what the doctor ordered!

I hadn't been able to find any info either by searching on the web or from my local motor factors. This is valuable information for other folk looking for a cheap caliper repair.

Repair kit now ordered and I will post here when it has been fitted. It is interesting to see that the same kit seems to fit VW T5 Transporters and Touaregs, although I think they are actually different calipers.

[60041]

I have fitted new seals to quite a few calipers over the years, it is not a difficult job. It is more than likely that the problem with yours will be a build up of rust on the caliper bore immediately outside the seal groove, ie between the pressure seal and the dust cover. Once the caliper is stripped down, it is easy to clean this area back to bright metal with a bit of emery paper, you can be quite brutal as it does not affect the sealing of the caliper in any way.
Any tarnishing or light corrosion on the piston can be cleaned off with some very fine wire wool, but be gentle here and make sure everything is spotlessly clean before you put it back together.
One final thing is to lubricate everything with "Red Rubber Grease" which is available from Motor Factors or classic car specialists, if you make sure there is plenty on the inside of the dust cover it will keep the damp out and help stop it happening again.

[keithjeb]

Originally Posted by greenfingers

Thanks Keithjeb - that's exactly what the doctor ordered!

I hadn't been able to find any info either by searching on the web or from my local motor factors. This is valuable information for other folk looking for a cheap caliper repair.

Repair kit now ordered and I will post here when it has been fitted. It is interesting to see that the same kit seems to fit VW T5 Transporters and Touaregs, although I think they are actually different calipers.

No problem, used them when I overhauled the fronts on my old Hyundai coupe. The caliper seals being the same size doesn't seem that surprising.

Have you got an airline to pop the piston out with? Don't forget to dress/reverse the sliders while you're there.

[Funky Diver]

Originally Posted by greenfingers

It is interesting to see that the same kit seems to fit VW T5 Transporters and Touaregs, although I think they are actually different calipers.

And a lot more besides, at least according to the ATE website.


Using

11.0101-5704.2. Guide Sleeve Kit, brake caliper
Trade Numbers: 260095
Fitting Position: Rear Axle
Brake System: ATE

Use th trade number to get the gen, the see linked vehicles, might help expand the search for parts

[Balistaff]

Originally Posted by 60041

It is more than likely that the problem with yours will be a build up of rust on the caliper bore immediately outside the seal groove, ie between the pressure seal and the dust cover. Once the caliper is stripped down, it is easy to clean this area back to bright metal with a bit of emery paper, you can be quite brutal as it does not affect the sealing of the caliper in any way.
Any tarnishing or light corrosion on the piston can be cleaned off with some very fine wire wool, but be gentle here and make sure everything is spotlessly clean before you put it back together.
One final thing is to lubricate everything with "Red Rubber Grease" which is available from Motor Factors or classic car specialists, if you make sure there is plenty on the inside of the dust cover it will keep the damp out and help stop it happening again.

Very useful, I'll try examining the calipers on the drivers side rear.
I have a 53 plate V70 that had a heating rear drivers side wheel occasionally. It was originally my late father's car and due to his retirement and then dementia it only has 50k on the clock. The point being that it had not been regularly services and sat for a good few years; it seems the rust must have built up, inside the rear brakes. Long story short, during a trip abroad the wheel was heating and eventually the rear drivers side brake pads were metal on metal. The car was examined at an Italian Volvo dealership south of Lake Garda and they replaced the pads only (€150) and recommended (firmly) that I should have the brakes examined and cleaned of rust when I returned to the UK. Unfortunately the wheel bolts were done up so tight that I knackered the wheel bolt key. After obtaining a second wheel bolt key from a company in Germany I was able to take the wheel off (after a near hernia) and spent a good couple of hours cleaning the rust off the disk/drum, replaced the hand brake shoes and used silicon on the sliders and caliper carriers. To be fair I didn't examine the calipers too much and should have, as I checked the wheel today and it was warm again (not hot) when the other three were stone cold after a 10 mile drive on country roads,...looks like I'll be examining the caliper next weekend.

[Balistaff]

I've been recommended to use Silicon Grease rather than Copper on the sliders and the caliper holders. Is this sensible?