Changing free play on Clutch Slave Cylinder

[Steve Davis]

Hey guys. Although I've been racing FV for over FORTY YEARS, I've never before used a clutch master/slave setup.. always used a CABLE. Now I have a car with a master/slave setup and after each session the free play is changing. After my first test day, I changed the slave cylinder to a brand new one, but still the same problem. I wonder if I'm just not bleeding things properly or if this is a common problem? I'm using same engine/clutch from my 'cable car' that almost NEVER needed adjusting, but now finding ~1/2" free play after only 2 sessions on the car, when it was marginally TIGHT before the first session.

Just me??

Steve

[Hardingfv32]

I can not say that bad cylinders have ever present themselves in this manner for me. I have always used hydraulic systems. The slaves do go bad very fast, but in your case you are going to have to consider replacing the master cylinder.

To bleed properly you must open a port at the highest point. I drill and tap extra holes in the slave to help with this. You can also fab a holding fixture to remotely hold/capture the slave while you bleed.

Funny how you/we are still learning after 40 years.

Brian

[Steve Davis]

Yeah.. amazing how MUCH there is to learn
I DID figure out what was happening today. The slave cylinder is actually TWO cylinders that screw together. They were coming UNscrewed, the base puck thereby moving further from the clutch actuating arm. Back when I installed the new cylinder, I just didn't notice that it was NOT TIGHTLY screwed together ... can't imagine WHY I wouldn't have noticed that.

I THINK it's all taken care of now.
Steve

[Steve Davis]

Wow .. I typed up a follow up to this thread, but it's NOT HERE, so guess I lost it somewhere along the way.

Even after tightening the 2 halves of the cylinder together, I still had issues with loosing clutch throw during a session. I found TWO more places that were not tight. I have 2 nuts that lock together to set the length of the cylinder to the clutch arm .. they weren't tight ENOUGH .. and also the bottom mounting shaft that screws into the cylinder has a LOCK nut that wasn't tight. Eventually I got them all. Did I mention this was the first time I've ever used a slave cylinder on my vee??

[FVRacer21]

Steve,

I have had the same clutch master and slave for almost 20 years....It will fail eventually, but....

This year I did had a washer pull through the clutch arm, was not a hardened washer or ball. So yes - still learning...

Got some pictures? I have a funny feeling you have a failing master, but does not match with your symptoms.

I assume you have checked the clutch arm for a cracked weld on the fingers? or a bad bushing in the non-arm side?

Sorry your race ended so soon.

Chris

[Steve Davis]

Thanks for the input Chris... After I finally found that last item of the 3 I mentioned, the clutch has been stable throughout the qualifiers .. and the 25 seconds of race that I got before the crash....
sd

[FVRacer21]

Glad you found it

Not glad so many of you had short races.....should schedule Runoffs AWAY from full moons.......

Chris