My car has had an issue for the longest time where it would lose clutch pressure than after a while it will go back to normal. last night was the worst case. the pedal went super soft and I had a real hard time going into 1st at stops, luckily I made it home ok. this morning I gave it a few pumps and I instantly had pressure. I drove for an hour this morning and it was fine.

Does anyone have any ideas?

 

What does the fluid level look like?

 

The fluid is always full, I have never had any issues with leaks or fluid loss. it happened after doing 30 minutes of driving after I finished installing my transmission.

instead of disconnecting the line like I usually do when removing the transmission I just removed the slave cylinder from the tranny this time to avoid having to bleed it.

I drove around this morning for an hour with no issue and I picked up some brake fluid. when I got home I removed the old fluid and refilled the master cylinder. I'll probably do a full flush and bleed later on today...

 

When my clutch was replaced last year, they also had to replace the slave cylinder since it wasn't holding pressure. And they installed SS clutch lines while in there.

If the flush & bleed doesn't keep the pressure, I would look to swap the slave cylinder.

 

it's an intermittent problem, right now it's fine but I'm sure at some point it will do it again.