*DECLARED! low clutch pedal fix*

Long story short I have a low clutch pedal. M/C and S/C are both new, OEM replacements, I have no pedal assembly issues (per jack's transmissions test method), flex line in hydraulics is an RRE braided line, clutch is a ACT 2600 w/ 6 puck, flywheel is RRE "no-name", clutch fork is less than 5K old. Jack's performed the M/C push rod adjustment.

All of that and still a low pedal. Somewhere here I read that there is a S/C that is bolt on that has a smaller piston (3/4" vs 13/16") than the factory S/C. After some research, I found that NAPA sells a version with the small piston, P/N 37918. I'm going to install this today, I'll let every one know.

 

Well it is installed. Initial impressions are great. The pedal is much higher off of the floor during engagement. I didn't even think to perform a drag test as I was so excited to finally see some improvement. Up until this latest change, I'd see clutch drag at 6600-6700 rpm. I'll do the drag test tomorrow. That should confirm my first impressions.

 

Have you tried adjusting it with the clutch adjustment bolt located on your clutch pedal. Simple and easy. It made a diff for mine

 

Yeah, it was actually Jack's Transmission that performed the adjustment. It did make it 10 times better, but the adjustment bolt was screwed all of the way out and I was still seeing that high rpm drag.

 

I am officially declaring victory! The clutch feel is fantastic now, the drag is gone, and the car is a lot easier to shift at high rpm. The napa slave was about 50 bucks. Worth every penny!

 

WHY THIS WORKS:

When the clutch pedal is depressed, the clutch master cylinder pushes fluid into the slave cylinder, which in turn pushes on the slave cylinder piston, moving it out. By going to a slave cylinder with a smaller bore, the piston is forced further out, depressing the fingers on the pressure plate sooner during the pedal stroke and, vice versa, releasing them later during the return stroke.

 

[ApexHunter]

Quoting galant1517:
All of that and still a low pedal. Somewhere here I read that there is a S/C that is bolt on that has a smaller piston (3/4" vs 13/16") than the factory S/C. After some research, I found that NAPA sells a version with the small piston, P/N 37918. I'm going to install this today, I'll let every one know.



There are two different slaves dependent on build date.

MD733227- 1990.06.1 – 1992.04.3
Green markings, 20.64mm OD piston

MD733623- 1992.05.1 – 1992.05.3
Pink markings, 19mm OD piston

 

[FlyingEagle]

galant1517 and I chatted about our setups recently, and other than my having an ACT 2100 PP setup with Fidanza alum flywheel, I replaced slave and master with OEM pieces and a new braided line.
Bled the system and adjusted the new master rod, system is working properly, even having pushed the slave rod in with the bleeder open to get fluid and air out doing a bleed myself.
I won't necessarily need to go the route of the smaller slave internal diameter to achieve further output movement with the same given clutch pedal movement.
Heck, I haven't even done a proper two person bleed yet, but my clutch is engagement is now well off the floor and more or less near the center to late third of travel from the pedal.
Thought I would post up my findings too, because it made a world of difference changing those parts that were able to keep up to the pressure plate previously used with a CFDF PP and clutch disc.
I did however install the ACT TOB, tossing aside the aftermarket TOB which may indeed be what OEM now supplies. (slaps forehead)

 

Hey there Tim. I am glad to here your car is running good now.