Bandit Master Cylinder on an 1150

[Greg B]

Has any one replaced their front master cylinder on an 1150 with one from say, a Bandit 1200?
I've put new rotors, pads, braided lines, rebuilt the calipers, and put a brand new stock master cylinder on my '85 1150 and there is way too much lever travel for my liking. And it feels kind of spongy. I've bled the crap out of it, and even had the local Suzuki shop take a look at it and bleed it, also. Just can't seem to get the right feel out of it.
Any thoughts?
Greg B.

[bwringer]

Hmmm....

Sounds like something still isn't right in your braking system -- my '83 850 has the same front brake system as the 1150, and I've added SS braided lines as you have. There is very little lever travel, and the brakes are quite solid-feeling. A later model MC might give you access to the groovy adjustable levers, but until you figure out where the problem is in your existing setup, the swap would be rather pointless.

I think you'd be very happy with the braking feel and power if everything was working right.

I had a really awful time with my new brake lines until I ordered up new aluminum crush washers (I called Paragon and ordered 100 at a quarter each, so I would never have to pay the bike shop $1 each for inferior washers).

You might also need to replace the pads -- they tend to wear at an angle, and when the angle gets too severe, this can make them feel mushy. I've also had far better luck by vacuum bleeding the brakes than simply pumping fluid through.

Also, are the calipers able to move freely on the pins? If they get cocked to one side or stuck, this can affect the feel. Make sure they're lubed and protected with the special brake parts grease.

[Greg B]

Brand new pads, copper crush washers. I did try vacuum bleeding first, then the old fasioned way. New pistons and seals in the calipers. Essentially the only thing NOT new is the caliper bodies. Now the lever comes halfway to the grip before I can feel any braking action. They felt good with the old master cylinder, but the sight glass had a bunch of tiny hairline cracks and the vibration would make it weep brake fluid. Not much mind you, but I had visions of it giving way at an inoppertune time.
By the by, do I need to get the grease from Suzuki?
Greg B.

[bwringer]

By the by, do I need to get the grease from Suzuki?
Greg B.

No, you can get brake grease at any auto parts store in handy little 99 cent foil packages or buy a lifetime supply in a can with a brush for $10 or so.

[bwringer]

When you pull in the brake lever, can you see the calipers move at all? The movement in properly functioning calipers is nearly microscopic. If you can see them move very much, something's not right there.

But after thinking about this for a while, I suspect that you simply need to bench bleed the master cylinder. Basically, remove the MC, fill it with brake fluid, then hold your finger over the outlet to act as a one-way valve while pumping the piston manually with a wooden dowel or somesuch. If there's air in the guts of the master cylinder, this is the only way to get it out -- you can't bleed the MC properly by pumping the brake lever.

And yes, bench bleeding gets pretty messy... brake fluid squirts everywhere.

Several folks have replaced the window with JB Weld -- knock out the old window, clean everything up with your favorite brake cleaner, then clamp a small piece of wood on the inside of the MC to cover the hole. Fill the hole with JB Weld or a similar epoxy substance, let it cure, and there you go.

I'm not sure if you need to coat the wood with something so that the JB Weld doesn't stick to it. I might use a small piece of sheet aluminum to back up the hole and leave it in place.