Clutch Master Cylinder

RWD4G · Post by **RWD4G** » Thu Oct 22, 2009 9:26 pm

I am wondering what clutch master cylinder you guys are using with the w-series trans? I know you can use the one off the donor car, but I think that will create issues with the vacuum booster, and brake master cylinder reservoir (this is on a conquest). A clutch master cylinder like the conquests that has a remote reservoir would be ideal. Which ones have you guys used?

Bill Hincher · Post by **Bill Hincher** » Fri Oct 23, 2009 3:07 am

the slave cylinder that comes with them is from an 85/99 Toyota non turbo supra and the master cylinder cylinder diameter is 20 mm

RWD4G · Post by **RWD4G** » Fri Oct 23, 2009 11:57 am

Thanks for the quick input. So the MKIII nt uses a 20mm diameter clutch cyl, anyone know what the starquests clutch cyl diameter is? Do you also have to take the stroke of the cylinder into account as well as the bore?

RWD4G · Post by **RWD4G** » Fri Oct 23, 2009 12:19 pm

Did more more searching and found the starquest clutch master cyl is 15.87mm (0.62in.) diameter. So my only question now is does anyone know of any cutch master cylinders with a 20mm (0.79in.) diameter that use remote reservoir?

Bill Hincher · Post by **Bill Hincher** » Fri Oct 23, 2009 4:50 pm

I havent looked yet but I dont think 15,87 would be a number the engineers would use, do you? it sounds awful small

RWD4G · Post by **RWD4G** » Fri Oct 23, 2009 6:26 pm

Thats what I thought. I looked it up in a 1989 Conquest FSM. Let me know if you find out otherwise. Thanks.

boise-nic · Post by **boise-nic** » Fri Oct 23, 2009 7:48 pm

The easiest way is just try and work with the stock setup. That way you are sure the swept volume of master and slave work perfectly. You are right, the brake booster is directly behind the clutch pedal. I think I found a work around though...

The stock clutch pedal has a bar that goes up and across the two other pedal and then goes out through the firewall...I am trying to figure out how to take advantage of this and reweld the lever arm of the clutch (that would normally go to the cable) to fit a push rod to go out to the master through the firewall. This area seems free of interference from the brake booster.
Also keep in mind that you do NOT have to mount the master on the firewall. All you need is a spot of the pushrod to go through to get to the master. Once nice thing about mounting it farther away is the change in angle as the lever rotates doesn't affect the master as much as say, if you had it mounted really close on the firewall. I'll snap some pics this weekend of what I'm talking about.

RWD4G · Post by **RWD4G** » Sun Oct 25, 2009 8:47 pm

Finally got some more research done on the clutch master cylinders. Here is the pages out of the Dorman catalog. The 15.875mm now does seem right, cause that would be 5/8in. Under BOTH the Conquest TSi and the Celica Supra the cylinder bore diameter is 5/8in. So we should be able to use either of the clutch master cylinders, right? Here are the pages I copied from the catalog:

boise-nic · Post by **boise-nic** » Mon Oct 26, 2009 12:19 am

^^^nice find!
I found a way to use both the master and slave from the supra. I used the stock clutch pedal and arm and added a metal 'leg' to extend it to the proper length and position for the correct stroke for the master. The hole is apready there for you, it is the spot on the firewall where the cable goes. Installed, I have about 1.2 inches of travel which I think is close to the max amount. The deflections are about what I saw on the junkyard car before I yanked it off. It doesn't seem excessive.

Horrible pic btw...

^Just a mockup with some plexiglass.

But the clylinder clears the brake booster great...

Once it's all welded up, I'll throw up some more pics...
I added a reinforcement pad that is riveted to the firewall to keep it from flexing.

So that's another way of doing it.