master cylinder window

Anybody know where to get a piece to replace the window on a master
cylinder without having to replace the whole reservoir?

'83 Honda VT750C Shadow

Thanks,

Tim

 

Thanks for the reply, that is exactly what I had in mind, just wanted to
see if anyone else thought along those lines. I was planning on
press-fitting the plastic into the JB so it would slightly bevel around
the edges for a stronger hold, since my concern then would be a pressure
blowout. That would be bad.

Tim

 

There's not *supposed* to be any pressure inside the reservoir, but
there are a lot of things in this world that aren't *supposed* to
happen. If you have a lot of air in the system, that could put pressure
on the reservoir as the trapped air heats up from braking, or the air
pressure differential between the inside and outside increases as you
climb to a higher altitude.

Expanding air, for whatever reason could work to push your plastic
window out of the reservoir, but this doesn't seem to be a common
problem, at least I've never heard of it happening...

It might have something to do with the rubber accordion bellows
underneath the reservoir cap. The bellows folds up flat when you push
on it. You fill up the reservoir with fluid to the correect level, and
the bellows will expand as the brake fluid level drops with brake pad
wear. This keeps the brake fluid near the hole in the bottom of the
reservoir so you don't pump air into the system every time you use the
brakes when the fluid is low...

Maybe the designers of the bellows figured you might experience the
pressure
differentials I mentioned, and they planned for a little bit of fluid
expansion, as well as a lot of fluid level dropping?

Then there are motorcycle racers, who either fill their reservoirs to
the brim, or use their front brakes so hard the fluid expands and
begins weeping out past the rubber gasket. The racers would put one of
those tennis wrist bands used to wipe the sweat off your face around
the reservoir to absorb the weeping fluid. But the little plastic
window never blows out under pressure...

 

[snip]

I always wondered why those things were on racer's master cylinders. lol

 

well, that explains that.

Thanks

Tim