clutch diaphragm position

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On my 2003 Silverado NV4500, I wonder how the clutch cylinder is supposed to be.

Do you push the diaphragm in and fill near the top of the reservoir

OR

Do you expand the diaphragm and fill it about halfway





Is there an art to it that will alter clutch feel, gear engagement and component longevity????




Thanks for any help!
 
I assume you're talking about filling up the clutch fluid reservoir that is attached to the master cylinder.

As long as there is some fluid in the reservoir, the clutch will work the same regardless of the amount. If it doesn't work normally, there's another problem.

The thin rubber diaphragm under the cap is just to keep air and moisture out. Same thing on the brake master cylinder.
 
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the brake cap doesn't have the diaphragm that expands though. On the clutch cap, the diaphragm (if expanded) can almost fill in the entire reservoir.


I think you misread.
 
This diaphragm as you call it just keeps dust out of the system, and fluid from spilling out. A well-sealing cap would have the same effect.

There's a tiny hole in the top of the master cylinder piston bore that's uncovered when the clutch is all the way up, so fluid can trickle in if there's any air. You only need one drop in the reservoir for it to work properly as the rest of the system will be full.
 
The design of the diaphragm is meant to be flexible enough to create a seal while allowing the level to fluctuate. The seal needs to be tucked up higher to allow enough fluid in the reservoire to operate the slave cylinder.
 
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Thanks asand1! I still don't understand what you are saying, but at least you understood what I was saying.

Does it matter if the rubber diaphragm under the cap is extended down into the reservoir OR is it better to be tuck into itself and practically take up no space?


The clutch is working, I am just trying to get the feel to be as great as can be. The other day after I greased around the pedal in the footwell (in the interior under the steering wheel) it got very light and smooth. Its like its effort was reduced to half and wasn't notchy anymore OR SQUEAKY. But then it came back and is still better but isn't effortless anymore.

I think what I greased (with SuperLube) but I had used dielectric/silicone/tune-up grease in the past, before I bought a tube of SuperLube, I greased the pushrod that goes through the firewall from the clutch pedal.


I really think y'all would be doing yourself a favor if you cleaned around your pedals. It seems to be a very neglected area.
 
Originally Posted By: Rand
Whats wrong with using the markings on the reservoir?




Thanks Rand! The marking looked a lot like a support piece. If that is what it is. My Saturn was like that. I thought there were no markings and you just were supposed to fill it as high without it spilling over.
 
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