soft brakes twin disc set up

dam10r wrote:

So if I keep the stock MC what is the best way to bleed the lines? I have done it many times, but can't get rid of the sponge. Thanks for all the other suggestions!

Buy yourself a Mighty Vac as a previous poster said. Start bleeding from the furthest caliper from the MC. Tap the lines with a screwdriver handle as you go. Quick movements of the brake lever expell small bubbles in the MC. A nice set up are the braided SS brake lines where each line goes up to the MC. Get rid of the splitter. Hope this helps.

I know this might be resurrecting a dead thread, but steell how did you eliminate the splitter running a dual disc set up on the '96 GPZ1100 Master Cyl.? There is only one outlet from the M.C. and obviously needs two lines (one to each caliper). Am I missing something here? :huh: Seeing as I have your old GPZ M.C. and two discs on your old set of mags (Thank you-they fit great! pics soon to come), this is of great interest.

Buckeye73z1 wrote:

...how did you eliminate the splitter running a dual disc set up on the '96 GPZ1100 Master Cyl.? There is only one outlet from the M.C. and obviously needs two lines (one to each caliper). Am I missing something here?....

Perhaps a double banjo bolt at master cylinder.

Click > www.z1enterprises.com/SearchResult.aspx?All=True&KeyWords=banjo

Good Fortune!

Some riders have has success by having the front brake lever squeezed overnight by use of a ty-wrap or rope. This lets most of the air bubbles out of the system.

Make sure there's enough brake fluid in the reservoir before calling it a night. Install the brake fluid cover after checking, put a ty-wrap squeezing the lever closed and check the next day.

MFolks wrote:

Some riders have has success by having the front brake lever squeezed overnight by use of a ty-wrap or rope. This lets most of the air bubbles out of the system.

Make sure there's enough brake fluid in the reservoir before calling it a night. Install the brake fluid cover after checking, put a ty-wrap squeezing the lever closed and check the next day.

We used to do that at the roadraces, after coming off the track from a race or practice session. It just takes light pressure on the lever to open the fluid circuit. Good tip.

Wonder if the OP ever sorted the problem?

By the way, if anyone has a Z1/KZ900 style rotor and right caliper (or even just a right caliper bracket will help)I am interested in buying it. I still have my Z1 forks and this limits my caliper choices. I was going to swap out my forks for Later KZ1000 forks and go with the newer calipers, but I've opted to rebuild my old Z1 caliper instead and need a 2nd one. I have a newer (either KZ1000 or GPZ750, not 100% certain-but I think they interchange)caliper and two KZ1000 discs I'll trade even-up if anyone is interested. I'll also sell the KZ1000 brake parts outright and am willing to buy the Z1 brake set up outright if need be. PM me. Thanks!

mjg15 wrote:

You mention that you have the original M/C. If you mean the one that was intended for a single disc then that is likely to be your problem. You will need an M/C with a larger piston to move enough fluid for the two calipers that you now have.

I'm not sure about the exact sizes on a 1000, but on the 550's that I'm familiar with the single disc bikes use a 14mm M/C and the dual-disc bikes use a 16mm unit. I would expect that you would find a similar difference on the larger bikes also. The correct M/C combined with some braided steel lines will give you the results that you were expecting.

I have the same situation on my KZ1000 LTD. The bike was equipped from the factory with dual discs. The PO crashed and wiped out the 5/8" bore MC and replaced it with a 14mm unit.
I discovered this when I bought a rebuild kit for the MC. The kit didn't fit. I got a 14mm kit and rebuilt the cylinder. I rode with that for 2 years and suffered a soft front brake. I could squeeze the handle all the way to the grip. I had reasonably good braking but not max effort and not overly sensitive. Last spring I searched for a 5/8" bore MC and came up empty. I wound up modifying the 14mm MC and installing a brass liner. It works great. I can't squeeze the handle all the way to the grip anymore. I have good control and the brass liner won't pit like the steel MC bore did.

I still have the special tools I made for the conversion and some of the brass for the liner. I'd be happy to convert yours if you like for the cost of parts and shipping. PM me if interested.

A tiny bit of air can give you fits. I bleed brakes by pumping fluid up from the caliper into the MC. It seems to dispel air faster than pushing bubbles down the hose with the MC.

Patton wrote:

Buckeye73z1 wrote:

...how did you eliminate the splitter running a dual disc set up on the '96 GPZ1100 Master Cyl.? There is only one outlet from the M.C. and obviously needs two lines (one to each caliper). Am I missing something here?....

Perhaps a double banjo bolt at master cylinder.

Click > www.z1enterprises.com/SearchResult.aspx?All=True&KeyWords=banjo

Good Fortune!

You're good!!

That is a good idea, Steell. I think I'm going to steal a page from your book on this one. Thanks again.