Holed front brake caliper piston

[jonesai]

I am replacing the brake hoses on my 1999 R1150GS with braided hoses.

I removed the brake calipers to clean them up and noticed that there is a hole in the face one of the pistons. The material on the face of the piston looks quite thin.

When in use the piston is permanently pressed up against the back of the brake pad and is self sealing to some extent so no water should get in to cause internal corrosion of the piston so I am inclined to leave it as it is as it has been working ok.

What is the best advice – leave as is or replace the piston and seals ?

 

[(RIP) Mark H]

Actually its not the piston but a plastic anti squeal device that sits in the hollow piston so it will do no harm to leave it, or I have heard of people removing them all, don't know if the part is available separately, maybe second hand ?

 

[jonesai]

Thanks Easyrider

I will try Motorworks for a secondhand spare and if not willl leave it as it is to squeal or not as the case may be

 

[B4ndit]

I have noticed my front brakes squeal when warm Might be time to strip them down. Let me know if you find a straight replacement for the anti squeal part.

 

[dancata]

I have noticed my front brakes squeal when warm Might be time to strip them down. Let me know if you find a straight replacement for the anti squeal part.

They could be squealing because only one caliper is working, or only one piston in one of the calipers is working. Before investing money in it, try to clean them and push them all the way in, change the brake fluid and see if they squeal more

Dan.

 

[B4ndit]

They could be squealing because only one caliper is working, or only one piston in one of the calipers is working. Before investing money in it, try to clean them and push them all the way in, change the brake fluid and see if they squeal more

Dan.

Cheers Dan. Its not a loud squeal and the brake fluid has been done recently. It was after that I noticed the squealing.

 

[jonesai]

I have tried Motorworks and the main BMW dealer .The anti squeal insert cannot be bought separately - you have to buy a complete set of new front pistons and seals for around £50 per caliper .
Motorworks don't have any secondhand as they would have to split the caliper.
Looks as though it will be going back together as it is

 

[Stewart H]

One of my front calipers has been without those for a couple of years, nothing has happened yet

 

[Peter]

Had that hole in one of the front caliper pistons on my 1995 1100 for 12 years plus. Had no problems. Bike done 80K. Ignore and do not worry!

 

[gently-does-it]

no bother

I have the same thing in my rear brake piston on my '02 GSA. No problems so far.