Girling Calliper Seized

[Forrest]

At least I think that’s the problem. Online research suggests that it might be the brake hose.

This is on my 1997 V90 Mk 1, but the callipers seem to be identical to those on later 940s.

I had a look at it yesterday. The outside of the offending calliper was very rusty. I cleaned it up with a wire brush and brake cleaner and checked the slider pins. The latter were fine.

I didn’t open the bleed valve because it looked quite corroded and I didn’t want the start of a nightmare. I cleaned the valve and applied maintenance spray for future consideration.

I could not get the piston to budge backwards with a g-clamp, prising with a jemmy or (sorry Laird!) using an SDS drill on rotor lock.

New calliper and a pair of flexible lines on order. My plan is to try cracking open the bleed valve to test whether it’s the calliper or the hose then proceed accordingly.

Any pearls of wisdom welcome.

Recommendations for a push back tool that works well with these callipers?

Presumably Napa DOT 4 Fully Synthetic Brake & Clutch Fluid will be compatible for topping up and bleeding.

I’ve got a pressure bleeder in the shed but have never used it. Presumably you don’t touch the brake pedal if bleeding using such a device.

Thanks.

[volvo again]

If you've got new caliper on order it's not worth the hasle of moving the piston in the old one, unless to satisfy your curiosity...
Using a pressure bleeder is easy, once you've connected up to the master cylinder just undo each bleed nipple in turn, makes changing fluid a doddle

[classicswede]

Make sure to check the length of teh new hose before fitting as hoses that are too short are often listed as fitting

[J liddy]

I have the self bleeder kit too if like mine you must not use any more than 20 psi on the presure hose let the air out
of your tyre to that presure or it might be a bit less .check what your self beeder instructions

[Forrest]

Mine is one of the ones you pump up like a garden sprayer. It has a gauge on the front and I think you’re supposed to use 15 psi. I must dig it out and re-read the instructions.

[Laird Scooby]

The Gunsons Easibleed is the best to use, if you have ABS use about 25-30psi but make sure all your connections are tight or you could end up getting a shower of DOT4 - the NAPA stuff you mention is fine.

As someone else further up mentioned (James i think), i'd just remove the hose and caliper and fit the new ones and bleed them through. Worry later about why the piston isn't moving back. Even if the hose has collapsed internally, after a period of time the pressure will release as the hose relaxes so you should have got some movement on the piston.

I made a pad spreader tool from an old pair of pads, drilled through the centre of both, bolt through one with two nuts to lock against each other to keep the head captive but capable of turning, drilled and tapped the other, screwed the bolt through then another two nuts on the end locked against each other to operate it with.









Should give you some ideas!

[J liddy]

I have only ever used presure of 20 psi dave .with my ezibleed brake bleeder I have ABS on my 900 volvo .bit worried too much pressure will blow the seals I've been told .and seen ezibleed own video on UTUBE I like your brake caliper puller!

[Laird Scooby]

Originally Posted by J liddy

I have only ever used presure of 20 psi dave .with my ezibleed brake bleeder I have ABS on my 900 volvo .bit worried too much pressure will blow the seals I've been told .and seen ezibleed own video on UTUBE I like your brake caliper puller!

Often the valves in the modulator block need a little more pressure to overcome their resistance Jim otherwise the system doesn't bleed completely.
As neither the Bosch ABS (as fitted to 7/9xx up to 1992) nor the Bosch ABS-2E from 92 can be live bled, this extra presure has to come from somewhere.

[Forrest]

A bit of an update on this.

I wanted to use the car for a 350 mile round trip over the weekend so had a quick look last week. I came to the conclusion the front pads were very worn comparing them to the new ones I had bought.

I bought one of these to push the pistons in properly.

https://www.amazon.co.uk/gp/product/B08594G73B

I discovered that one of the slide pins was sticking on the opposite side to where I thought I had the problem.

Using the ratchet tool, and with the bleed valves on the calipers open, I was able to push the pistons both sides back easily.

I replaced the slide pins on the side that was sticking and fitted new pads both sides.

The brakes work fine and stop the car without pulling but both sides feel as though they are binding very slightly. This is enough to make the wheels warm but not boiling hot on a long drive.

I have compared to one of my other 900 series cars which had its brakes serviced professionally recently and that one is not perfect but the front wheels on it will spin a little bit longer before they come to a halt.

I’m wondering if this will sort itself out as the new pads wear and bed in or whether I need to do something else. I didn’t replace any other parts. The Delphi brake hoses I bought would be long enough (thanks Classic Swede for mentioning the need to check this) but I managed to convince myself they had the wrong end on them not realising the infamous 1329693 connection adapter is from M10 male to M10 male, as described here.

https://www.volvoforums.org.uk/showthread.php?t=316504

[Forrest]

I have now replaced both front calipers with professionally refurbished exchange units. This, and pressure bleeding the brake lines has made the brakes feel firm and removed some residual judder still occasionally noticeable after just replacing the pads. One of the original calipers was prodigiously rusty. The other appeared to have been replaced at some point in the car's history.

However, removing the front flexible hoses for replacement with new has so far defeated me. I suspect it is necessary to apply heat to the corroded junction with the hard brake line. However, I am wary of doing this on small hydraulic lines. Maintenance spray over a period of several weeks seems to have made little difference.

Since the side that is most corroded is the side where it would be relatively easy to replace the hard brake line from the ABS controller I might wait until I have got a spare pre-made hard line available and then try potentially more destructive methods DIY or just ask the garage to sort it out next time the car is booked in. Not afraid to admit my limitations!