Triumphrat

Jacqueslemac · 03-25-2008

I'm trying to replace my rear pads right now. They're completely down to the metal at 15,000 miles.

It was easy until I got to the part about pushing the pistons back in to make room for the new pads. No chance. They're completely seized solid. Any suggestions?

Jacqueslemac · 03-25-2008

Okay, I managed to get the pistons freed up, but they won't retract very far.

In fact, there's not enough room to slide the new pads in, let alone then put the assembly back over the rear disc.

Should the pistons slide right inside their sleeves or, if not, how much should be sticking out?

Thanks for your help. Otherwise I'll be putting the old pads back in and ride to a dealer.

iansoady · 03-26-2008

The pistons should slide back till they're just about flush with the caliper face. You need to clean them thoroughly before you push them back otherwise the muck and rust on the piston can tear the seal.

blacktiger · 03-26-2008

Quote:

Originally Posted by iansoady

The pistons should slide back till they're just about flush with the caliper face. You need to clean them thoroughly before you push them back otherwise the muck and rust on the piston can tear the seal.

Quite. Also, your problem might be too much fluid in the reservoir causing a fluid lock. Take the cap off the reservoir to let the fluid return. Be sure to wrap a rag around the reservoir to catch any overflow.

Jacqueslemac · 03-26-2008

I removed the cap from the rear brake fluid reservoir, but still no joy.

On Friday, it's booked in for a service with the dealer who sold the bike to me 6,000 miles ago, so they can sort it out.

From now on, I'll be removing the caliper and re-greasing every couple of months to stop it happening again.

What has surprised me is that I use the bike every day for commuting, so I use the back brake quite a lot when I'm filtering, yet it's still seized.

Silverstripes · 03-26-2008

When I did mine some 3 weeks back had the same problem. The solution was to clean the exposed pistons and then I used am old vice with thin jaws to "Clamp" the pistons back into the caliper.

I then applied the brake again and repeated the clamping exercise to get the pistons moving and all was well.

I does take some pressure to get them back in and you want to do both at the same time or one will go in and the other come out further. Also worth taking the top off of the brake master cylinder. This is located behind the side panel, as fluid will return to this cylinder when you push the pistons in.

Good luck