Intermittent floppy clutch pedal

[needlenose]

If my truck idles for very long(5 min or so) in neutral, the clutch pedal goes completely limp. Pumps right back up immediately. No leaks, full of fluid. Works perfectly fine all other times.

I assume it's just time for a new m/c. But what the what?

 

[subway]

check your line routing, could it be getting to hot and allowed to flex if it is by an exhaust manifold???

 

[needlenose]

check your line routing, could it be getting to hot and allowed to flex if it is by an exhaust manifold???

Nope. I'm one of those ****** guys running a certain evil 5.9l six cyl.

The exhaust is on the other side of the engine.

I've been running manuals my entire life and I've never see something like this. Will probably just replace everything, but I would like to at least understand the problem.

 

[subway]

Nope. I'm one of those ****** guys running a certain evil 5.9l six cyl.

The exhaust is on the other side of the engine.

I've been running manuals my entire life and I've never see something like this. Will probably just replace everything, but I would like to at least understand the problem.

haha, i am one of those sleezy guys to, my 5.9 is still made by IH though

besides that i have never heard of something like that, can you get under it and have someone pump the pedal when it acts up. putting eyes on it might show you the problem.

 

[oregon96psd]

Does it not do it after running down the road for the same amount of time, no shifting just in one gear?

 

[Thewespaul]

Check your clutch pedal bushings, maybe the firewall heats up and it’s affecting the clutch pedal feel? That’s my only other guess. Pretty much dead on master cylinder wear signs.

 

[needlenose]

Does it not do it after running down the road for the same amount of time, no shifting just in one gear?

Nope. Just when sitting still idling.

It's not something I really do very often. But have had two occasions waiting with little kids in the truck and the a/c on. Did it both times. No pressure at all. I have to pull it back up with a toe. Also had it do it once while fueling. Only 5min and it had lost about half the pressure.

 

[oregon96psd]

Strange, as far as the clutch hydraulics care it shouldn't matter if it's in gear or not.

 

[BrianX128]

Maybe a certain rpm creates a vibration that shakes the master cylinder just right to where the piston lets fluid by and it falls without pressure but it's such a slow leak it doesn't happen under other conditions? I don't know it's weird for sure.