Hydraulic Clutch

[Texasbigblock]

Hi all,
I’m a 67-72 guy but need some square body help this time. I have a 1970 Chevy body, that I put on a 1985 dually chassis. I’m using the hydraulic clutch setup from the 1985 (trans, slave, bell housing, fork, etc...). I’m using the master from an 88 because the earlier models had an angled master that was more difficult to mount to the 1970 firewall. So the master is 1988, but everything else is 1985 stuff.
I have read tons of posts on how to bleed these and I’ve successful bled these before on different trucks. But, after many attempts, on the truck and on the bench, I still have no pedal. With the engine running I can’t get the truck into gear even with the pedal to the floor. I feel very little resistance from the pedal except right at the floor. When the clutch is held, I can go under the truck and it appears that the push rod on the slave is fully engage with the fork (I can’t move the fork AT ALL by hand any further.

Also, this shouldn’t effect my current issue, but is there supposed to be any kind of return spring on the clutch fork?

Any thoughts?
Still air somewhere?

I’m starting to miss my manual clutch.

[mongocanfly]

Are you getting the clutch fork arm to travel far enough to release the clutch in your opinion...you could have a bad master or slave...or there's still air...that's why I like my mech clutches..all clutch arms I've seen have return springs but I havnt messed with a hyd clutch in a long time...
I doubt you could move the clutch arm by hand when engaged ..lots of back pressure from the pressure plate

[v30crewcab]

87 master is exactly the same as an 85, unless you got an s10 one. better post some pics so we can figure it out.

[Texasbigblock]

I apologize. The master is for an 88. I’m using the 1970 clutch pedal, but I modified it some to hook up the newer model push rod. I set it up so the rod would push in about 1” into the master. I guess it could possibly not be pushing in far enough. Can anyone verify how much travel this push rod should have?

[Texasbigblock]

I edited the original post to 1988 master.

[hatzie]

I had all kinds of trouble getting the air out of the slave cylinder on my 85 back in 1996.
It looked like the slave was angled such that the bleeder was not at the very top of the slave so air could still be trapped.
I unbolted the slave and oriented it with the bleeder at the very top and then opened the bleeder. More air burped out and the system worked after I re-installed the slave.

This was on a completely stock system so your hybrid might not be the same problem.

[v30crewcab]

try taking the slave loose, and pushing the rod in and out slowly for awhile. thats the best way to get all the air out. if it doesn't work good then, might be mismatched sizes not working together.