Master Cylinder issues...lol
 

I have a sort of unique problem with my master cylinder, actualy a couple of problems...lol. I had to take my rear out of the car due to a tire rub problem I was having. Oh yeah, I have an EM car. Anyhow, I was rubbing inside driver/outside passenger on my rear tires. I of course assumed that the fellow I had bought the car from had not located the mounts properly when he relocated them due to his using a custom made Ford 9" IRS setup. I took out the rear, which entailed totaly disassembling it to get it out and I of course had to disconnect the brake lines. It turned out that the trouble wasn't in the mounts at all, but in the body itself and it required some machine work to the rims and the IRS unit to try and solve the tire rub problem. In any case, when I put it back in, I found that I can no longer get any pressure from my master cylinder. I have tried bleeding it with it in place on the car but can't seem to do so. I continue to get air in my bleeder and can't figure out why, and also what appears to be water, but from where or how, I have no idea. To make matters worse, I would just pitch the thing and start over with a new one but I have no idea who makes the damn thing....lol. I have Jag suspension in the front and that was what should have been in the back until the previous owner went with the Ford IRS. Sooooo, I'm thinking maybe it's a Jag unit but of course I can't find a pic of a Jag setup anyplace. I guess my question is this, any ideas why I can't get pressure and I keep pulling air ? and does anyone know of a decent unit that will work in place of what I have ? I am running manual brakes, inboards in the rear with mid size GM calipers, Jag's in the front. The current setup has two seperate units mounting to each side of the brake pedal. Do I have to use this type of setup or can I go to a single piston ? A local parts shop suggested I go with a '74 Corvette unit that's made for manual brakes, it's like $16...lol...but the cost really isn't an issue, I just want to get my car back together before summer comes and goes...lol. Any ideas would be most appreciated.

Cliff

Cliff,

It sounds like you have a typical race master cyl. setup. Dual cylinders with a balance bar.

First try disconnecting the pushrod from the front cylinder and try to arrange the pushrod to get a full stroke on the rear M/C..

Also, you should bench-bleed it if the fluid all drained out. This means disconnecting the outlet from the M/C, running a hose from the outlet into the reservoir, and pumping the piston several times to pre-fill the cylinder.

Another method is to use a vacuum-bleeder. I've had good success with them.

As far as the cylinder itself, it could be a Girling, Wilwood, or Tilton. The bolt spacing is standard for these units, but be sure you get the same piston diameter you had before, or you could upset the brake balance.
Check http://www.summitracing.com/ or
http://www.jegs.com/
They both carry Wilwood and others.

Good luck,

David
 

Thanks for the advise. I have tried to bleed it using a bleed tool but I keep drawing air somehow from the rear unit and also what appears to be water, but I can't figure for the life of me how that's happening...lol. I'm thinking that the best thing to do is probably just replace it since I can't get ANY pressure in it at all. I tried to bleed it back into itself but I can't even get enough pressure to do that. I'm going to try one more time tomorrow and if I have no luck, I'm just going to replace the unit. Thanks again.

Cliff

Cliff,

Check all your lines, it sounds like you may have a leak somewhere that is allowing air in.
Also, remove your bleed screws and wrap a few rounds of teflon tape on the threads, but do not get it on the tapered seat portion.
The teflon tape will help prevent air being drawn in around the threads when vacuum-bleeding.

Good luck,