Seized brake pistons - best course of action?

[Dom_]

One of the pistons on my front right caliper is seized, and not for the first time. A few weeks ago I tried to the G clamp trick to force the seized piston out and gave everything a good clean, but the piston has now seized again, so it looks like I need to do a full rebuild of the caliper or pick up a new caliper entirely.

Just wondering really, what do you guys think is the best thing to do? I've never rebuilt a caliper before and for all I know the one on there now is 26,000 miles old. Is there much work involved a caliper rebuild? Is it worth rebuilding what could be fairly knackered calipers?

I noticed SV Spares has a caliper going for 35 quid and since they claim they check for 'correct operation' while calipers are still on the bike I am tempted to go down that route. I've noticed quite a few people on here have mentioned SV Spares, so I assume they're a good/reliable/trustworthy company?

As a result (I can only assume) of the one seized piston I have already had to replace the corresponding disc once and don't fancy having to do that again. :?

Any advice much appreciated. :)

Cheers,
Dom

[Scoobs]

It's not too difficult to do a caliper strip but the parts are bloody expensive for what they are. If you can get cheap calipers it is better to go that route. Unfortunately you can't guarentee the quality of these calipers and you may have to do the job anyway. You pays yer money...!

[mart]

plenty of cheep calipers on ebay or if you want to wait for a week i could sell you mine

[Warren]

its a gamble really, you could try compressed air to get the pistons out, but your best taking it somewhere as it is quite a dangerous procedure.

once their out, see exactly why they are seizing, if its due to dirt, they can be cleaned up, corrosion might mean a new piston, but i wouldnt buy a brand new piston (there very expensive), your much cheaper getting a calipar of ebay, then taking the good parts off it and putting it in the old one.

[Dom_]

Thanks for the replies guys. The more I think about it the more it seems worth doing the seals rather than picking up what could be an equally crappy caliper second hand.

I assume it's dangerous as the pistons can come out fairly quickly? My plan would be pump out one piston (G clamp on piston #2) > replace seals, clean up etc > replace piston > pump out piston #2 (G clamp on piston #1. Is that likely to work?

And does anyone know of a good place to get seals from, or is it a case of overpriced Suzuki OEM bits all the way?

Cheers again for the suggestions!

Dom

[northwind]

I assume it's dangerous as the pistons can come out fairly quickly?

Like bullets :) Aim at the ground! I had the bright idea of aiming mine at a bucket which was already full of used rags. It put a hole in teh bottom of the bucket ;) Last time I did it I fired them into water, makes a mess but it works and avoids damaging the pistons.

[Viney]

If you are going to replace the pistons, then a pair of 5 holes(Water pump grips) will get the pistons out with a bit of persuaison.

I had the same problems. Replaced both calipers with low milage ones...along with the discs...i now have brakes :D

[Dom_]

Well ideally I want to get the pistons out and see what they look like before forking out for new ones. Although I'm starting to think that the chances of them being seriously damaged just from being pumped out are quite high. :lol:

The water trick sounds like a good/fun way of doing things, think I'll give that a try!

[lukemillar]

I assume it's dangerous as the pistons can come out fairly quickly?

Like bullets :) Aim at the ground! I had the bright idea of aiming mine at a bucket which was already full of used rags. It put a hole in teh bottom of the bucket ;) Last time I did it I fired them into water, makes a mess but it works and avoids damaging the pistons.

Ditto. I got my dad to give me a hand doing this on some 4 pots this weekend! It was unbelievable. Split the caliper, blocked off the holes and had one of us using the compressor while the other held the caliper. I would be very careful! The water idea is good - I opted for rags and got a tiny chip on one piston at the end. Should be able to file it smooth, but it is annoying.

[Viney]

TO be honest, id take off the cliper form the fork still attached to the bike, then pump the pistons out as far as you can using the lever (Keep the pads in) then just wiggle the pistons out. Im sure that the other piston will move. Make sure theres loads of rags around to mop up the fluid, and dont get nay on the body work.

[Dom_]

TO be honest, id take off the cliper form the fork still attached to the bike, then pump the pistons out as far as you can using the lever (Keep the pads in) then just wiggle the pistons out. Im sure that the other piston will move. Make sure theres loads of rags around to mop up the fluid, and dont get nay on the body work.

I will try wiggling them out before doing anything more drastic. The seized piston will definitely move with some persuasion - it certainly did last time and I can't believe it will be seized worse than that after just a few weeks.