BRAKES REBUILD

[Wookiee]

xris_xcess

Great!

No cylinders? Ive seen quite a few options for other bikes, with stainless steel. I’ll try to match the diameter, depth, etc.

Any tips for cleaning the current cylinders? Is my “fine steel wool pad” idea seem ok?

I normally use brake fluid and an old tooth brush, something too abrasive will score the cylinders.

[Umoth]

I am in the process of a brake rebuild.
After 6 years and under 10k miles.
The callipers on my other bike lasted 20 years, and they were not this bad when I had them done.

One piston on the front caliper was seized.
I would ride off and I could feel that the brakes were on, then after about 3 minutes suddenly it would free off. It got hot, and metal expands when hot. The piston freed off.
The rear caliper piston was rusted to death.

In both cases I would call it cheap steel with cheap and minimal chrome plating.

So off came both callipers and away to Powerhouse for a full recon with stainless pistons.

3 weeks later nice shiny calipers refitted.
The rear master cylinder died during bleeding.
Not a problem, get a new one.
69600-48H20
Oh, no longer available.
So, I can try a seal kit, but if the cylinder is ducked what to fit?

Anyone had to replace their rear brake master cylinder using something other than the correct one?

[xris_xcess]

I was going to ask if anyone had details of the parts:

Pistons (outer diameter, depth)
Piston seal (outer, inner diameter, thickness)
Piston dust seal (outer, inner diameter, thickness)

Sorry to hear about your troubles Umoth. Would calipers have some standard mounting options? So maybe from another bike/brand? How about looking for the Nissin part number?

[Umoth]

I bought a seal/piston kit (new old stock off ebay) just in case.
It is still available from Suzuki.

I took the cylinder off and the piston was stuck at the end of the stroke.
A small amount of corrosion had built up in the bore of the cylinder behind the dust boot, just enough that the return spring inside the cylinder was not able return the piston.
In service the pressure of of the brake fluid was able to overcome this slight resistance.

Put the cylinder in a vice, poked a small rod into the hole the brake hose banjo-bolt goes into, with the intention of trying to hammer the piston out, and the piston shot out the cylinder like a scared cat, hitting a work collage on the back. 

5 minutes later we had found all the bits that had scattered themselves all over the floor.
They got a good clean.
Very carful use of a mild acid removed the corrosion, and a little silicone (rubber safe) grease did the trick.
Full function now restored the brakes bled easily.