Clutch- Excessive Free Play When Cold

[JT58]

I have an 87 Squarebody with SM 465 4 speed manual. I have done so much work on the truck the past year and it is coming along real nice. The clutch pedal has excessive free play (like 2") when it cools off or when cold. It will engage very close to the floor when this happens. After starting and driving it for like 5 minutes it goes back to normal with like 1/4- 1/2" free play. From what I can see there is no adjustment, being a hydraulic clutch. The clutch and Slave cylinder are brand new, I just had them replaced about 6 months ago. Fluid is full. Could it be air in the line? Or a defective slave cylinder? Could it be anything else?

 

[fast 99]

One thing to try, those hyd clutches can be a headache to bleed. It sounds odd but bleed it backwards. What I mean is push fluid in from the slave cylinder. Get one of those hand pump style oil squirters, a new one that has never had oil in it. Suck the fluid out of the master. Put a piece of hose on the oil can, fill with brake fluid. Open bleeder on slave, attach hose and pump fluid in until master is full or overflowing. May have to do it a couple times. If air is the problem this procedure should get it out.

 

[nvrenuf]

It's stupid but with the slave installed it will trap a tiny bit of air. Remove the slave and bleed it while holding the slave with the bleeder high.

 

[JT58]

Thanks I'll try both suggestions! I read about bleeding it backwards. I'll have to get one those oil cans. I had one years ago so I have used them in the past.

 

[Ricko1966]

I've bled problem slaves by hooking a vacuum line to manifold vacuum the other end to the slave. Start the truck,Crack the bleeder listen for Idle to change,close the bleeder. It's worked for me twice.