Saturday 19 May 2018:Well while I'm waiting for engine parts to arrive, I thought I'd crack on with a job that needs to be done before I can take it back out on the road, reconditioning the front brake Master Cylinder. Not surprisingly, after sitting for 18 years in a garden shed, the piston seal had shrunk a little bit, allowing fluid to leak out.
It's always easiest to strip the MC while it's still mounted on the bike, so the first problem was that someone had previously butchered the lid screws:
ZZR1100 BRAKE MC REBUILD by
terry prendergast, on Flickr
ZZR1100 BRAKE MC REBUILD 1 by
terry prendergast, on Flickr
ZZR1100 BRAKE MC REBUILD 1A by
terry prendergast, on Flickr
No biggie, I just introduced the MC to my "Little Friend", Mister Dewalt..........
ZZR1100 BRAKE MC REBUILD 2 by
terry prendergast, on Flickr
I took a little bit more material than I would have liked, due to using the one sharp drill bit that I own. Oh well, it doesn't need much.
ZZR1100 BRAKE MC REBUILD 3 by
terry prendergast, on Flickr
It wasn't hard to see where the fluid had been leaking from:
ZZR1100 BRAKE MC REBUILD 4 by
terry prendergast, on Flickr
The banjo bolt was nice and shiny though!
ZZR1100 BRAKE MC REBUILD 5 by
terry prendergast, on Flickr
Anyhoo, I took it off the bike without incident, and using a scriber, as opposed to a dozen different sized circlip pliers, was able to pop the circlip and the whole piston assembly out.
ZZR1100 BRAKE MC REBUILD 6 by
terry prendergast, on Flickr
In the past I've had a sh1t of a time getting the circlip out, but after I removed the protective rubber donger, using the scribe's pointy end it popped right out, took maybe 30 seconds? I installed the new rubber piston seal on the new piston, and checked it against the old one to make sure I had it assembled correctly:
ZZR1100 BRAKE MC REBUILD 7 by
terry prendergast, on Flickr
I cleaned the cylinder out with a little brake cleaner and paper towel, squirted a little through the bleeder hole to make sure it wasn't blocked, and reassembled it. I think it looks a little better now.
ZZR1100 BRAKE MC REBUILD 8 by
terry prendergast, on Flickr
OK, so I re-installed it on the bike, and bled the MC. Once again, bleeding the MC is a must before bleeding the whole system, as if there's air in the MC, you'll spend forever trying to pump it all the way down into the calipers. Within 5 minutes, I had a rock hard lever! Not bad for a 26 year old bike, or a 58 year old man, for that matter........
ZZR1100 BRAKE MC REBUILD 9 by
terry prendergast, on Flickr
I was lucky to find 2 new stainless screws that just needed shortening, and they finished the MC off nicely. I'll bleed the whole system later, I need to change the fork seals (as soon as the new seals turn up) so I may, or may not need to strip the calipers too. We'll see. All in all, it was a nice easy job for a miserable Saturday afternoon.
ZZR1100 BRAKE MC REBUILD 10 by
terry prendergast, on Flickr