New Here: Need help

[eam1946]

New here to this site. Have not got it all figured out yet.

I have changed a 1980 F-350 cab to a 1986 cab. It has a 6.6 engine. I am converting to a hydraulic clutch because the truck had severe linkage problems and would never engage the clutch properly. I have installed a new clutch and pressure plate, bearing, fork, and fork seat. I built a bracket for the hydraulic clutch, and I cannot get but about a 5/8 inch stroke at the clutch fork, it seems to lack enough power to disengage the clutch. I have put a master cylinder on it for a 86, as well as an 86 460 engine slave cylinder. Gone through about 2 quarts of fluid in bleeding, and cannot get any air out when bled at this point. Tried back bleeding too. Not sure what to do next.
How much stroke should the slave cylinder have? Any clues to how much pressure is used to disengage. Thought maybe the master and slave might have been defective and have replace again with new ones. No change. I have an 1986 F-250, with identical clutch parts and it move farther than the problem truck. I have run out of ideas what is wrong, and no one I know has an answer so that is why I am here. HELP!!!

 

[DNFXDLI]

Welcome to FTF

I'm going to move your post over to the Gen 7 section where it might get more of a response.

 

[Fellro]

Watch the firewall when you apply pressure to the master. These cabs have an issue with the firewall flexing. There are repair kits available when this happens. My 86 had a massive crack that let the firewall move about 1". I got a kit from Ford, but they are getting harder to find. There is a company making them now aftermarket.

You may need to move the slave closer to the clutch fork. Witht he limited stroke, you may had to set it such that it doesn't move much to start moving the fork. Also, there are adjustable push rods for the master as well. Make sure the bushing is good in both the pedal assembly and the push rod.

 

[eam1946]

Clutch Master cylinder

The firewall has no movement. The adjusting rod on the master cylinder has been set to max length with just a tiny bit of free travel before the cylinder starts to activate. Still stumped on this problem. Bracket under dash appears ok, and see no unusual movement when activated.