Floppy c20 truck clutch pedal.

Hey you guys might've remembered my thread from asking about building a beastly 305. Well, the same friend, and the same truck. His trying to get the transmission going. And this trucks clutch pedal is floppy. It will return with the return spring. But it does not have the clutch pedal feel that a hydraulic or even cable operated clutch pedal would have. Is this normal? 
I told him I think there should be at least some pressure when depressing the clutch pedal since the pressure plate would give some spring back

How does the clutch work? Engage / disengage?

In reply to CJ (FS) :

Yeah the clutch will function. You can shift the truck through gears. It's just the weirdest feeling with your foot, like something is missing

If it doesn't slip it is fine.

There are few manufacturers on the planet that made worse feeling clutch pedals than GM.

What year is the truck? 

In my experience when  they start to feel that way it's only a matter of time before the pressure plate needs replacement.

Yhere are a few other things that can cause weird feeling on the clutch that may be easier/cheaper to correct:
-   hydraulic issues (air, bad rubber lines)

- worn fork/ball stud

- worn push rod/fork

- assembly error by previous owners (disk backwards, wrong parts)

-flywheel turned excessively 

I'd start by pushing the pedal by hand should help you get a better feel for how far it moves before the throw out bearing contacts the pressure plate.

Any GM I've driven with a hydraulic clutch the pedal moved less than an inch before you could feel the change in resistance from the pressure plate. mechanical linkages were typically adjusted to an inch of top pedal, but play in the linkage on the other side of the firewall could cause strange feeling in the pedal.

You can also watch the movement of the clutch fork and/or move it by hand to see how much room there is between the pressure plate  and throw out bearing. At the fork you'll have only a fraction of the movement you see at the pedal before the tb contacts the pressure plate. 

As I said in the original post. There is no hydraulics. Just linkage rods. 

In reply to Vajingo :

Over time the rods and holes in the linkage and Z-bar will wear. Take it apart, clean it up and see what needs to be welded up and re-drilled.

If that all looks good, the pressure plate may be going bad.

In reply to Vajingo :

I missed the part about the linkage. Everything in my post still applies, except the couple items specific to hydraulic components.

In that case, I'd suggest doing as Shawn says and inspecting everything for wear.

When checking make sure everything lines up properly, and doesn't misalign/shift when pressing the clutch pedal, since there are more places where the linkage can be misaligned or develop play. Even weak/damaged/incorrect motor mounts, trans mounts, and body mounts can change the alignment and feel of the clutch.

As mention in my previous post check the fork for wear at the ball stud and where the pushrod contacts the fork. While you have the adjustment rod backed off to do this you can also check the linkage and pedal for binding or play. After inspecting, adjust the pushrod at the fork to have approx 1" of top pedal before the TB contacts the pressure plate. IIRC setting the pushrod to 1/8-1/4" of play at the fork will be close to 1" at the pedal and then you can fine tune.

That truck may have a spring style pressure plate instead of a diaphragm style, which will feel different than most cable/hydraulic clutches. The pedal force will increase over the whole range of travel and not plateau/drop off like a diaphragm pressure plate. 

Unless you find problems in the linkage or that it's way out of adjustment, symptoms you describe have been a failing pressure plate on any GM truck I've had with mechanical linkage for the clutch. 

I had a similar issue on my Comet. I replaced the Z-Bar  bushings and it got "better" but still had more slop than any cable or hydraulic.

If it's a Zbar setup, don't forget if the engine/transmission mounts are toasted it's going to walk all over the place and be loose as hell.