Triumphrat

Bootysmak · 07-08-2006

Has anyone ever put an aftermarket master cylinder for the front brakes on an 02 955? I'm sick of the mushy one. It was good for like a week after I bought it. I bled it, put fren tubos on it. I'm convinced that that master cylinder piston seal is defective. I have read on here that a lot of people have had a similar issue, so I'm not even going to mess with changing the seal. I think that I'm just going to get a brembo from a wrecked ducati, or maybe even a japanese master. Has anyone ever tried this? is there a specific one that is a good match? I also know that there are different piston sizes. Does anyone know what size the piston is in the stock 955 master? I have heard 12mm. Thanks, Jake

Japawhat02 · 07-08-2006

have you tried cleaning your pistons. It works wonders. :-D

Bootysmak · 07-08-2006

I haven't tried that, but like I said, the brakes only really had a good bite for a coouple of weeks when it was brand new. So I doubt that there was enough debris accumulated after such a short amount of time for that to be the issue. I will give that a shot though. I guess that it can't hurt. If it is just going to go back to mushy after a couple of weeks again though, hardly seems worth the effort. Also, on other bikes I have owned, I never cleaned the pistons one, nor did I ever have to change the fluid and the brakes were always super responsive. I guess it could have something to do with the fact that they were brembo components.

bradtx · 07-08-2006

Jake, I don't know exactly what it is, but the issue isn't really with debris. Some have pinned it on the surface treatment of the pistons.

If you pull the calipers off and remove the pads I bet you'll find that not all of the pistons are extending out of the caliper when the brake lever is pulled in...this is what we finally found on Japawhat02's bike.

It's easier with two people, one at the brake lever and one at the caliper. Extend those pistons that will come out and clean with brake cleaner and a toothbrush. Push those back in and hold them in the caliper while pulling on the brake lever to get the 'stuck' ones out. Clean them as the others and repeat with the other caliper. You won't even need to bleed the brakes.

It's been six weeks or so since Japawhat02 did his and they're better still than the '04's, equal to the RC51's.

Food for thought...

Brad

Bootysmak · 07-08-2006

Hmmm, I'll definitely give that a shot then. It is definitely sounding a lot cheaper than a new master, now that I have been pricing some out, hahaha. They are only 2 pot calipers right?

bradtx · 07-08-2006

Jake, They're four piston calipers.

Brad

Bootysmak · 07-08-2006

ok, thanks a lot

Dad_Roman · 07-08-2006

Two on the side yer lookin at!

kit:

Bootysmak · 07-21-2006

Athough my bike now has other issues, I had the shop pop all the pistons out while they were changing the tires. The front brake now has a hair trigger again. Like new. Thanks so much for the advice.