big red are great and easy to deal with , I have had rebuild kits from them and they really know their stuff when you need to chat to some one on the phone. my RS6 calipers were an odd ball and to them it was no hassle parts in the post next day and at great prices .
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Bryan Williams
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The new ones are 18mm,checked on the Just Kampers site, theirs for this van are also 18mm,so I think they are the correct discs, I measured the old ones across the high outer ridge - 15mm, obviously thinner inside.Check the caliper and pads fit back on....clean up the caliper carrier too as previously suggested.
Don't feel bad....I did exactly the same thing. Volvo use 2 sizes of disc....I got all the way to putting on the caliper and pads too and though hang on something looks very odd here....it turned into quite a job that one...a lot of foul language as I had bought the parts a few months previously! In my loft there is a nice new pair of undersized v70 discs....one day I might have use for them
...they are next to the v70 front suspension arms....which don't fit an XC70 (who knew!)
Looking at the originals to me it looks too tight....the wear on the originals won't be on the edge so I would have thought the new/old edge thickness would be similar?
Bryan Williams
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What do you do? Seal and piston out, what do you block the hole up with, would you block off the slider holes?
You could leave the caliper on the van & suspend it in the citric acid solution. Otherwise leave the flexi hose on the caliper & keep the open end out of the liquid. The CA will only attact the rust so there's no need to strip the caliper. You will need to degrease it as any oil or grease will stop the CA getting at the metal.
Note - do not use CA if theres any aluminium on the caliper!
Pigeon_Droppings2
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Pull the piston/seals out and just stick it in the citric acid is what I do....wash, dry, paint and then I just rinse a little brake fluid inside before I rebuild to get anything out of the casting.
If you are worried about the piston bores I think if you grease them it'll keep the acid off them...think I just stuck mine in there though and they were fine.
Just because I haven't seen it mentioned here, I have a tool in my collection that was designed 20 or so years ago by the SUR&R company, their #BB007 that used a purpose made air chisel hammer that had an indent for the head of the bleed screw, and a set of short lengths of piano wire which got driven into the center of the bleed screw to prevent it from collapsing when it was torqued on removal. The wire also transferred the impact to the base of the bleeder which also helped break up the silt and corrosion seizing it to the threaded bore of the bleed port. There are at least two other companies making/selling copies of this tool in the US currently, but the basic design principle isn't complicated and a cheap Chinesium air hammer bit and maybe 5-10 minutes on a lathe to center drill a 6-7mm x 10mm deep recess on center of it's face will make an acceptable copy. I've used this tool to good effect in the days when my daily drivers were Alfas or VW/Audis as everything in the northern rust belt in the US seizes up solid or corrodes and falls off within a couple of years. More info here: https://surrauto.com/kits/bb007/ And another little mention in a related post with better pictures: https://ricksfreeautorepairadvice.com/remove-stuck-brake-bleeder-screw/ Hope this helps, but usually there seems to be 10-15% of these bleeders that defy the best efforts of removal as they shuck threads and seize when you start to turn them.
Bryan Williams
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I will try but it's gonna take a while to dig out a big enough hole for the whole van, and ca is cheap but that's a lot of lemon juice.
Pigeon_Droppings2
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Couldn't work out if you were joking
....just in case...the citric acid comes as powder....get mine in 5kg tubs fro Amazon but I think lots of places sell it too.
Bryan Williams
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Yeah crumby joke, even I'm not that thickCouldn't work out if you were joking
Thats a new one on me - looks interesting and I can see where they are coming from, even if I don't agree with "causes the bleeder to case-harden" - needs a degree or two of heat and some carbon rich stuff for that
The best way I've found to stop seized nipples - fit new ones with plenty of anti-seize, then undo and re-lube them every year, and replace them every other year - at a quid a nipple, its cheaper! Although last time, I fitted brass ones from Automec - we'll see how they have done in the next decade . . .
Bryan Williams
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Attacking the other side today, how far would you go filing this, or even bother? Worth greasing up and putting back on?
Melvyn Best
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That’s more like it
Nice job! It may be obvious but if you set a pad into the yoke you can see exactly where you need to file. Also file the groove where the disc runs.
The pad also slides on the caliper, usually the anti rattle spring so you need to clean that too. The flat part the non moving pad sits on can corrode & that would leave the pad tight on the disc.
Bryan Williams
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Well got it on, went for a spin couple of miles, braked hard couple of times.
Seemed OK, got back, hot as ****, smokin..
Took the wheel off, burnt my hand.. Let it cool, the disc had blued around the hub it got so hot.
Took it all to bits again, wanted to release some pressure to see how easy the piston pushed back but couldn't loosen the bleed or the hose connections.
Give everything another file, the pads have a clip on anti squeak shim clipped on and it's got a kind of rubberised coating, this was rough and gungy on the ends so I filed that off. The pads sat loosely I pushed the piston back a couple of times with a g clamp, it took a bit of effort but I don't know how easy it should go.
Everything looked OK although I didn't clean up the area where the springs sit like you pointed out.
I went for another spin, braked as normal didn't try to slam on.
Got back there was still heat, nothing like before but still to warm I think, the other side was a bit warm.
I'm thinking the piston isn't going back.
I fancy doing getting it out having a look, doing the seals.
Never done this, well probably in the seventies, but I can't remember breakfast so..
Do they just pull out, can I do it on the vehicle, as I can't disconnect it, if the piston comes out can I flush bleed that line out through the piston hole.. I know I'm probably going to be getting a new caliper but I'd rather try to get the piston working first, if it is that.. Cheers.
Also the pads on both sides are not touching on the middle of the pads, jude braking on the outer half inches or so
Seemed OK, got back, hot as ****, smokin..
Took the wheel off, burnt my hand.. Let it cool, the disc had blued around the hub it got so hot.
Took it all to bits again, wanted to release some pressure to see how easy the piston pushed back but couldn't loosen the bleed or the hose connections.
Give everything another file, the pads have a clip on anti squeak shim clipped on and it's got a kind of rubberised coating, this was rough and gungy on the ends so I filed that off. The pads sat loosely I pushed the piston back a couple of times with a g clamp, it took a bit of effort but I don't know how easy it should go.
Everything looked OK although I didn't clean up the area where the springs sit like you pointed out.
I went for another spin, braked as normal didn't try to slam on.
Got back there was still heat, nothing like before but still to warm I think, the other side was a bit warm.
I'm thinking the piston isn't going back.
I fancy doing getting it out having a look, doing the seals.
Never done this, well probably in the seventies, but I can't remember breakfast so..
Do they just pull out, can I do it on the vehicle, as I can't disconnect it, if the piston comes out can I flush bleed that line out through the piston hole.. I know I'm probably going to be getting a new caliper but I'd rather try to get the piston working first, if it is that.. Cheers.
Also the pads on both sides are not touching on the middle of the pads, jude braking on the outer half inches or so
carriers look tidy , thats a good job , did you clean the rust out of the holes where the pins go too i normally run a hacksaw blade round the lips that the seals sit on to give them a chance too , if the nipples wont undo your putting calipers on , but nothing to stop you stripping out the old ones for a look . at least with new calipers , pipes and flexi become handy .Well got it on, went for a spin couple of miles, braked hard couple of times.
Seemed OK, got back, hot as ****, smokin..
Took the wheel off, burnt my hand.. Let it cool, the disc had blued around the hub it got so hot.
Took it all to bits again, wanted to release some pressure to see how easy the piston pushed back but couldn't loosen the bleed or the hose connections.
Give everything another file, the pads have a clip on anti squeak shim clipped on and it's got a kind of rubberised coating, this was rough and gungy on the ends so I filed that off. The pads sat loosely I pushed the piston back a couple of times with a g clamp, it took a bit of effort but I don't know how easy it should go.
Everything looked OK although I didn't clean up the area where the springs sit like you pointed out.
I went for another spin, braked as normal didn't try to slam on.
Got back there was still heat, nothing like before but still to warm I think, the other side was a bit warm.
I'm thinking the piston isn't going back.
I fancy doing getting it out having a look, doing the seals.
Never done this, well probably in the seventies, but I can't remember breakfast so..
Do they just pull out, can I do it on the vehicle, as I can't disconnect it, if the piston comes out can I flush bleed that line out through the piston hole.. I know I'm probably going to be getting a new caliper but I'd rather try to get the piston working first, if it is that.. Cheers.
Also the pads on both sides are not touching on the middle of the pads, jude braking on the outer half inches or so
octo0072000
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change the flexy pipes on the front could be delaminating on the inside failing that i would be looking at a couple of new calipers
Edward Teach
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4 1/2 " angle grinder with a wire wheel, will clean all the rust off the caliper that needs to be removed,
Any where you can't get to with the wire wheel, use a cold chisel and a hammer,
Push the piston back with a G clamp, make sure other other side, if removed, is clamped as well, or that piston may well be pushed out !!
Clean the centre of the wheel, where it fits over the disc, it may be corroded !!
Grease the sliders if needed,
If it has stainless spring plates, and they are not in the pad kit, clean them with a wire brush.
Cleaning the sliding pad surfaces as you have done is good work, just don't remove too much !!
edit: the new pads will take a good 100 miles to bed in and work efficiently,
Braking hard will not do them any favours, that is why they may have got hot,
You will notice the brakes improving as the first 20 or 30 miles are driven,
Treat them with care, bed them in slowly !!
Any where you can't get to with the wire wheel, use a cold chisel and a hammer,
Push the piston back with a G clamp, make sure other other side, if removed, is clamped as well, or that piston may well be pushed out !!
Clean the centre of the wheel, where it fits over the disc, it may be corroded !!
Grease the sliders if needed,
If it has stainless spring plates, and they are not in the pad kit, clean them with a wire brush.
Cleaning the sliding pad surfaces as you have done is good work, just don't remove too much !!
edit: the new pads will take a good 100 miles to bed in and work efficiently,
Braking hard will not do them any favours, that is why they may have got hot,
You will notice the brakes improving as the first 20 or 30 miles are driven,
Treat them with care, bed them in slowly !!
Last edited:
They should push in very firmly. This 12 year old American carp rear was bluing the disc last year.
Broke two cheap G clamps trying to push that back in. Needed the car the next day and £40 buys a new one, vs. lots of hours, piston and seal kit etc.
Don't know how that brake pipe got thru an MOT, btw...
Broke two cheap G clamps trying to push that back in. Needed the car the next day and £40 buys a new one, vs. lots of hours, piston and seal kit etc.
Don't know how that brake pipe got thru an MOT, btw...
Bryan Williams
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I'm this far along, want to check and replace seals, how does the piston come out?cheers
