Clutch Pedal Fade

[Rawkkrawler]

MC is brand new.

Simple unit with a built in large resevoir.

Floor mounted. Slave is about 8" above MC.

Brakes had a similar issue. I was using a hand operated vacuum pump at each bleeder then moved to a air operated vacuum bleeder with no luck. The old fashioned two person forced out the remaing air and the brake now feels good.

I tried the same method to the clutch but didn't get the results as the brakes.

[RICK LAKE]

Rawkkrawler Lets get a little info first,
Does your clutch pedaL problem happen all the time? Car hot or cold?
Does your Hydro slave cylinder have a bleeder valve?
I have not seen any cars running a check valve in the line for a bleed back system. I would want the fork and bearing to come clear of the pressure plate in the bell housing. If the system has a high mounted reserve tank there should be no problem with where the master and slave are mounted. If the air is blend out and correct adjustments are done.Try this way to bleed
1/2 Fill the little tank and cap it get car of floor jacks, you will need 2 people to do this. Push in the slave cylinder piston all the way in. This check valve maynot allow this way to work, Have your top person, SLOWLY press the pedal in to expand the slave again until it hits the fork. You want to do this a couple of times, after 4-5 time, do this and have someone watch for air bubbles in the fluid when the slave is pushed in. If there are small bubbles you still have air in the system and will need to keep doing it this way until they stop or add vacuum to the resv tank and repeat this method. Once this is done now we will bleed the system again from the bottom if you have a bleeder on the slave cylinder, Just like bleeding brakes, Pump,Hold, Bleed, and release a couple of times. Use a small clear hose to catch the fluid in a bottle that has some fluid into we don't want any air being sucked back into the system. Do this 4-5 times. If you see air, keep bleeding. DON'T pump the pedal fast. Slow steady speed.
After you have the bubbles gone with the system we need to check fluid temp after a drive. If the pedal is hard at the start of a drive and turns to a sponge after 20 minutes sound like a heating problem or bad seals in either the master or slave cylinder. If the line is right by a header or the block, we need to get some shielding material to stop the heat from heating the fluid. They sell raps, tubes or heat reflector tape at Jegs or Summit. The Homedepot sell this stuff in rolls for heating/ac systems. It's siulver on one side and 3M stickem on the other. Cut to size and rap twice. You may also have to run a DOT 4 fluid instead of a Dot 3. It will take a higher heat. If this doesn't work either rebuild the master and slave or replace both and repeat above. Good Luck Rick L. Ps took me 3 hours to get mine working and not having a spongy pedal. I have evrything shields or rapped to help with heat soak problem.