Front brake was stuck on; will it happen again?

[TheLeeds]

Originally Posted by bluesntwos

I was quoted about £50 for a new one but can't really wait that long so looking for a used one.

A few on ebay being broken for spares....

https://www.ebay.co.uk/sch/i.html?_f...pares&_sacat=0

[lynns hubby]

Originally Posted by bluesntwos

I would agree with greasing the caliper pins if only as a preventative measure. My daily-use 940 has just had a seized pin. When I tried to remove it, it sheared off. The caliper carrier is now scrap and they are actually quite hard to come by. Volvo can get them from Sweden but they are classic parts so you are waiting anything from a couple of weeks to over a month. I was quoted about £50 for a new one but can't really wait that long so looking for a used one.

If you are good with a drill you can get the sheared pin out. Even if you do not tackle it yourself keep the carrier as an engineering shop will be able to drill the snapped pin out. (probably for a beer token if you can get someone to do it during thier lunch hour).
As it happens I have just had the exact same problem with my Trooper rear brake. Bought a new carrier and slider pins as I work away and was not due back to work for a couple of weeks. Brought the old carrier out to work with me and I have drilled the old snapped pin out. Well I drilled and tapped it M8, then used a long M8 bolt with a nut and washers with a larger nut to draw against used the M8 bolt and nut as a "Puller" worked a treat so I now have a spare.

Obviosly, prevention is better than cure so every time you check your brakes, clean and re grease the sliders.
I got caught because this was the first time I had seviced the Trooper since buying it.

Oops should have added, YOU WILL NOT NEED GO TO M8 ON YOURS. The pins are larger on my trooper than our 940

[martin calva]

Thank you. Hoses were replaced four years ago or so, so rebuilding the calipers is likely to be the way forward. Martin

[martin calva]

Originally Posted by lynns hubby

Not 100% sure about the type of brakes ons the V90 as I have allways had 940s.
If they are the same, then the caliper is conected via slider pins, it could be either the caliper or one ore both slider pins that are, or were siezed.
The fact that you say it was OK on the way home suggests that it was not fully siezed but tight. I would still be inclined to remove the pins, clean up everything, a twist drill of the correct size is good for cleaning out the bore for the slider pins, lubricate with silicone grease or High temp grease NOT COPA GREASE. Also I would press the caliper piston back in a couple of turns with a "G" clamp, unwind a couple of turns, leave the "G" clamp in position and pump the pedal till it goes tight (the piston will have come up to the pad on the clamp). Do this several times, or until it is noticably easier to wind back in, asuming it was tight in the first place.
All this asumes that you are confortable working on your brakes of course.

Many thanks. That all makes sense.

[martin calva]

Originally Posted by lynns hubby

Not 100% sure about the type of brakes ons the V90 as I have allways had 940s.
If they are the same, then the caliper is conected via slider pins, it could be either the caliper or one ore both slider pins that are, or were siezed.
The fact that you say it was OK on the way home suggests that it was not fully siezed but tight. I would still be inclined to remove the pins, clean up everything, a twist drill of the correct size is good for cleaning out the bore for the slider pins, lubricate with silicone grease or High temp grease NOT COPA GREASE. Also I would press the caliper piston back in a couple of turns with a "G" clamp, unwind a couple of turns, leave the "G" clamp in position and pump the pedal till it goes tight (the piston will have come up to the pad on the clamp). Do this several times, or until it is noticably easier to wind back in, asuming it was tight in the first place.
All this asumes that you are confortable working on your brakes of course.

Thank you.

Yes, I'm happy to work on brakes.

Is copa grease NOT silicone? It does not mention the word silicone on the can but somehow I had the impression it was. Maybe simply because they recommend it for exhaust system nuts etc.
Martin

[lynns hubby]

Coppa grease is not really a grease for lubrication. It is in fact an assembly compound. It has short term lubrication for assembly which is great for threads etc but not for long term lubrication of surfaces designed to work together under lubrication. The trouble with coppa grease is the lubrication dries out under certain conditions, heat being one of them. It just leaves a coppa film. The other issue being that it reacts with the rubber components as in your pin boots and makes them swell and go soft which then alows water, dirt, brake dust etc in which defeats the job of the boot.
That is why silicone greas is the prefered option as it DOES NOT attack the rubber bits.
Also when I mentioned earlier about cleaning out the holes the pins fit into with a twist drill, I obviously meant by rotating it with your fingers and not with any form of power tool.
It seems that people jumped on the band wagon when factors started selling copa grease as brake grease. The only thing I use it for is a small film behind the pad on any contact area to stop "Squeal"

[Laird Scooby]

Originally Posted by martin calva

Is copa grease NOT silicone? It does not mention the word silicone on the can but somehow I had the impression it was. Maybe simply because they recommend it for exhaust system nuts etc.
Martin

No, definitely not Martin. At the risk of sounding sarcastic, the clue is in the name - copper grease - whether it's spelled copper, coppa, copa or whichever variety of spelling they use for marketing the stuff, it is copper based grease.

It's essentially very tiny flakes of copper suspended in a high melting point grease to prevent nuts seizing onto bolts, studs etc from heat, corrosion etc.
It can also be used between alloy wheels and steel hubs to prevent eletrolytic corrosion which can cause the wheel to stick to the hub.

Until very recently, copper grease was always the default grease for brake mechanism parts - rear of the pads (not the friction surface) to prevent squeal, slides to prevent seizing and so on.

However over the past few years, silicone grease has gained in poularity for use in place of copper grease, why i don't know as they have similar properties.

I use silicone grease on door seals, sunroof seals etc to keep them moist and prevent them drying out, squeaking etc and also as an alternative to dielectric grease on battery terminals as unlike hydro-carbon based grease, it won't carbonise once hot and cause problems.

[martin calva]

Originally Posted by Laird Scooby

I use silicone grease on door seals, sunroof seals etc to keep them moist and prevent them drying out, squeaking etc and also as an alternative to dielectric grease on battery terminals as unlike hydro-carbon based grease, it won't carbonise once hot and cause problems.

That's interesting. Yes, I found it is good for sliding doors in shower units. I use it for things like unions for the braking systems of old cars to prevent corroding up solid years in the future.

I always have a small tube of silicone grease on hand but I don't know where to buy it in quantities suitable for car maintenance. Any suggestions?

[Laird Scooby]

Originally Posted by martin calva

That's interesting. Yes, I found it is good for sliding doors in shower units. I use it for things like unions for the braking systems of old cars to prevent corroding up solid years in the future.

I always have a small tube of silicone grease on hand but I don't know where to buy it in quantities suitable for car maintenance. Any suggestions?

I tend to keep it as a small tube for the simple reason a little goes a long way and once you get dust/dirt in it then it's difficult to find some clean stuff.

For that reason, if i was to get a tub, this would be about the biggest i'd go :

https://www.amazon.co.uk/Silicone-ge...ilicone+grease

Goes without saying you'd have to be scrupulously clean when using it but there are probably other options similar, that was the first tub on Amazon i found, ebay would probably have a bigger selection.