How to tell if Clutch Master Cylinder is bad?

[HSSS427]

I have ERA #414 and the clutch wouldn't disengage the other day. Put it on the lift and there was fluid leaking from the line between the master and slave cylinders. Bob at ERA said they have upgraded that fitting and is sending another line. In the meantime, I pulled the rubber boot off the slave and fluid came pouring out. So, assuming blown seal, I replaced the slave (only $35). Replaced the original line to the master and tried to at least seal up the slave banjo connection end with gasket sealer. Now I can't get it bled using a Mityvac vacum pump. I've pulled about half a quart of Valvoline synthetic through the system and am still not getting any pressure on the pedal.

After that long preamble, here are my questions:
1) When using a Mityvac off the slave bleed valve, do you just ignore the clutch pedal end of things and just use the vacum to pull fluid through the system? Or, do you still need to have the clutch pedal half way depressed and then close off the valve before bottoming out or releasing it?
2) I feel like I'm drawing air into the line, either from the feed line from the resevior to the master, or from the connections on the line from Master to slave. There isn't any fluid in or around the rubber boot on the master. What's the best way to tell if the master cylinder is bad or if it's just a leak in the lines?

Thanks!
Scott

[Tony Radford]

Scott,

I'm in the midst of a clutch disaster myself. The first wrong thing I did was to put non-DOT 3 brake fluid in the system. I used some DOT5 silicon-based fluid and then read all of the "red flags" saying to never use silicon fluid in a hydraulic clutch system. Since then I've changed out the slave cylinder. I noticed the same thing this morning, pulled the slave boot and fluid came pouring out.

What a bummer.

[HSSS427]

Tony,
I hear you......I read the threads you'd posted and understood most of it. I'm assuming the Valvoline Synthetic is OK as it doesn't mention that is has silicon in it, but can't say for sure.

I'm trying to decide if I should just replace the master cylinder as well and just go with refreshing the whole system now. Bummer is my dad is in town and I wanted to take him for a ride, but doesn't look like I'll get anything sorted out before he leaves tomorrow.

All I seem to be able to confirm is that air continues to be pulled into the system somewhere. I'm going to fiddle with the connections tomorrow and try to seal up the threads real good and see if that works. If not, then I'll probably get the new master cylinder on Monday and go from there.

Let me know if you come across any miracles!
Thanks!
Scott

[Rick Parker]

Scott: You have mail. Plus this:

If the trouble persists check the bores of the slave and the M/C for scoring or a piece of foriegn material between the rubber cup and bore surface.

Good Luck



Don't scare your Dad too bad, BUT make understand why we like these cars so much.




Rick

[trularin]

weirhouse, if you can NOT pull a vacume, then there is an openning in the line or seal.

You MUST fix that first.

When you can develope a vac with the hand pump and it holds, then try to bleed the clutch.

Just my $0.02

[HSSS427]

Thanks Rick for the mail and Trularin for the advice. I removed the line, checked and cleaned everything, and then was able to put it back in using an in-line fitting instead of the banjo on the slave end. Greased the bleeder valve threads and then put the vacum hose on real tight using a piece of safety wire twisted around it as a clamp. As Trularin said, it now would hold a vacum so as the Stones said I just "let it bleed." When the bubbles stopped I sealed it off and the clutch pedal was like a rock. Couldn't budge it, so went back and adjusted the shaft to the clutch arm off the back of the slave as Bob Putnam had suggested. Then adjusted the master shaft a bit as well, and now the pedal feels right. Too late to start it up without catching holy **** from the wife for waking the house so will see how it works in the morn. Will let you know and thanks again for the help.

BTW - I imagine dad will be a bit aprehensive since he still remembers my teenage driving days, but he was the one who bought the brand new 69 mustang way back that got me into Ford fever. I think he'll enjoy taking it for a drive!

[HSSS427]

Great day for a car ride. The clutch worked fine but was not engaging until the pedal was about 1" from being all the way out. I adjusted the slave rod length and now it's working like a champ. Appears the key for me was to make sure all the connections are clean and tight. Did have a small amount of fluid coming from one of the connections after the run with dad, but toqued it down and everything appears dry now.

Got to go out on my own and even had a little fun with a blue vette. Nice guy - he showed me a good road to "clear it out" as he put it. He was even honest enough to admit he had it floored and that I was still pulling away from him......ahhh the good life!

[trularin]

It doesn't get any better than this.

Congrats!!!!!!