JaredAwells

So I have a 1987 corvette with the Doug Nash 4+3 and the clutch fluid would slowly go down and I’d just put more until one day my pedal went down straight to the floor so I just put a new slave master and line and now I’m trying to bleed it and I have someone pumping the clutch i got a few bubbles out but now the clutch goes half way down and can’t go any farther I’m not getting any bubbles out of the bleeder valve and the plunger on the slave isn’t moving at all had anyone ran into this problem

jmgtp

I’ll premise this by saying I’m not familiar with the 4+3.

If the 4+3 hydraulics are at all similar to the ZF6 there is an aluminum shim on the master cylinder that you must transfer from the old cylinder when installing. If you do not, the symptom is as you described. Piston in cylinder would bottom in the bore at about half of the pedal stroke.

I’ve been successful bleeding these things two ways. One with a pneumatic operated vacuum bleeder. Other by pumping pedal a lot as well as holding it down for a few minutes and sliding foot off.

JaredAwells

I was able to get it the linkage between the pedal and the master wasn’t right and for any one who may read this I’ve fount what I think to be a great method of bleeding I filled the resivor with fluid I had someone watch it as I crawled under and before I mounted the slave I took a 3/8 extension and pushed the slave all the way in and held it for a few seconds then slowly let itself back out the idea is the air will go out the resivor and only suck fluid in you must be careful not to let it suck more air hence the friend watching the resivor I hope this helps
I’ve been successful bleeding these things two ways. One with a pneumatic operated vacuum bleeder. Other by pumping pedal a lot as well as holding it down for a few minutes and sliding foot off.[/QUOTE]