600 Rear brake caliper

[ando7p]

Lo all. You may be surprised to hear that my rear caliper of my '97 600 Divvy is totally seized. Can't seem to find anyone who has one for sale that looks half decent.

Wondering if anyone knows of a reputable place to go, or if a caliper off another machine would fit. If so please let me know what bike I could get one from. Many thanks in advance.

[max900]

Keep an eye on Fleabay is your best bet there always popping up
failing that get your local garage to remove the old piston and give everything inside a very good clean and fit new seals and piston and you should be alright

[bighairymuppet]

if the seals are not buggered rework it take the pads out clean the surfaces of crap even using cotton bud or toothpick round pistons . something to lubricate as much externally and maybe even wd40 (watch flammable) to break rust crust. Clamp pipe and take it off .

Using a g clamp to push pistons back in gently with a a bit of card in between and use air pump to on open bleed valves (one at time) push them out (make sure you put something In between like old pads or wood splint).
working back and forward gently lubricating as you go it'll eventually loosen up.

Only work them a few millimetres (5?) each way at a time and make sure don't over extend them .
Its worked on many a old caliper lot of work but worth it especially when your skint.

[bobh]

I had a similar problem a year ago.

Not having easy access to an air line, in the end I used water-pump pliers to rotate the pistons to free them off. The pads were worn out (probably because the pistons weren't going back in so causing the pads to rub) so the pistons were already poking quite a long way out of the caliper body, so there was plenty to get hold of. Despite trying to protect them with rag etc., they inevitably got a bit scratched. But a piston and seal kit actually turned out to be not a lot more expensive than seals alone.

I've probably still got the old pistons, which I stoned down with a view to re-using them before I realised that it wasn't going to cost much more to get new ones. You're welcome to them if it'll help. PM me if you want them.

Bob

[ando7p]

Thanks Bob. The caliper really is seized though. It did this a few years ago when I managed to get the pistons moving again. At the time though, one of the bleed nipples sheared, so I had to back bleed. Passed its MOT and didn't use the rear anyway so didn't mind about poor brake at the rear.

This time only one side moves. Have tried excessive air pressure with the 'good' one clamped but all it does is leak now, hence why now looking for a new caliper. The only ones I've seen on 'bay look in worse condition than the one I've got.

[biblebasher]

if you use an air line, be careful. a mate of a mate lost the sight in one eye after sneaking a quick peek if anything was moving. shot out like a bullet!

[bobh]

If an air line won't shift it, maybe hydraulic pressure will? Air is usually 7-10 Bar but you can get at least 10x this with the hydraulics. Safer too. Maybe worth a try (if you haven't done it already).

Failing that, and thinking about trying to rotate the piston to free it, if you can get in with a Dremel or similar to make some grooves or holes in it which would allow a bar to be applied to turn it.

Bob

[ando7p]

Tried everything. Even modified 12 inch pipe grips wouldn't turn the bad one. Was thinking of filling the chambers with a highly flammable liquid and putting it in the microwave for my next attempt ......

[eliminator]

Where are you ando7p? I had the same problem, blew the pistons out at work on the hydraulic test rig, I can pump up to about , ? I've forgotten but enough to have blown my pistons out when they were seized

I'll blow it out if u can get it to me



I'm in south Hampshire

[ando7p]

Thanks for the offer. I am in the East Mids so am quite some distance away. Getting to the point of applying brute force and hoping for the best. Even if I get the pistons out I still need to salvage the bleed nipples. One is gone, and I reckon the other will go too!! Will have to find those easy-outs again....