Brake piston ejaculation distance

[hairyhippy]

Hi,

I've got a 2002 1150 GSA with rubbing brakes. How far out can I push the caliper pistons for the purposes of cleaning? I'm scared of not being able to get them back in again.

TIA Pete

 

[ssray]

easure the depth inside and push them out just over half that, they are not hard to refit, I use a gcramp to `assist` me
Ray

 

[Stewart H]

When I had the same problem I had to remove the pistons and seals completely, the cause was salty corrosion in the seal groove behind the seal forcing the seal to drag on the piston, working very carefully I did manage to disasemble clean and reassemble the caliper without damaging anything, the overhaul kits are quite expensive as they include new pistons.

 

[Trullion]

Isn't this a bit premature?

 

[dancata]

When I had the same problem I had to remove the pistons and seals completely, the cause was salty corrosion in the seal groove behind the seal forcing the seal to drag on the piston, working very carefully I did manage to disasemble clean and reassemble the caliper without damaging anything, the overhaul kits are quite expensive as they include new pistons.

So... would it not be ok for one to use regular o-rings from the o-ring dealer and reuse the pistons? Or have some new pistons made on a lathe?

I asked the dealer where I get the orings from and he said that the material that they are made of can face gasoline and brake fluid. So it's just up to finding the dimmensions for the pistons and o-rings.

Perhaps someone can help with the above request?

 

[colint]

So... would it not be ok for one to use regular o-rings from the o-ring dealer and reuse the pistons? Or have some new pistons made on a lathe?

I asked the dealer where I get the orings from and he said that the material that they are made of can face gasoline and brake fluid. So it's just up to finding the dimmensions for the pistons and o-rings.

Perhaps someone can help with the above request?

Motorworks do complete repair kits or all the bits to refurb see attached
http://www.motorworks.co.uk/bmw/pro..._15_30_HA_30&header_text=&header_text_image=0

 

[ducatiparts.110mb]

So... would it not be ok for one to use regular o-rings from the o-ring dealer and reuse the pistons? Or have some new pistons made on a lathe?

I wouldn't. I've not stripped BMW calipers, but the ones I've looked inside use square section caliper seals, not round o rings. Round ones may fit but they wouldn't work as well.

On the subject of turning up some caliper pistons then technically yes you can make whatever you want, but the tolerance and surface finish are so fine that you'd probably be better off buying new ones.

I'm not trying to scare you off but brakes are fairly critical, and unless you understand absolutely everything about it then its better to replace with new rather than manufacture your own.

Mark

 

[Myke Rocks]

And I thought I was the only one

Isn't this a bit premature?

Maybe the others are a bit slow!


Myke

 

[hairyhippy]

They're still rubbing. This is doing my head in.

 

[Two wheels good]

just a thought..

..could it be the pads? The edge of the pads sticking in the calipers?
Grinding a little off the metal base might help. (I don't mean the friction material)