Slave Cylinder... Again.

it's only the slave if there is fluid leaking from the bell housing (externally)... if theres fluid near the clutch pedal itself that's the master...

OK, I tracked down the rsr ctc one from WHOOSH. .. Now if I could only get the mechanics to believe that the problem is the slave......

It's going in tomorrow but they insist on examining (and repair or replace) the master cylinder as they think ... and correctly so.... that 99% for the time this kind of problem with cars --stuck pedal-- is the fault of the MC. but we know that the slave is where the problem lies with THESE cars... .. I can't seem to get them to change their approach. Now I can understand that they don't want to have to charge me any more than they need to with unnecessary repairs--They're a good shop. I told them what's going to happen.... They'll look at the master, bleed the system, pronounce the problem fixed, and in few months I'll be back with the same problem. Maybe then they'll believe?

OK, I tracked down the rsr ctc one from WHOOSH. .. Now if I could only get the mechanics to believe that the problem is the slave......

It's going in tomorrow but they insist on examining (and repair or replace) the master cylinder as they think ... and correctly so.... that 99% for the time this kind of problem with cars --stuck pedal-- is the fault of the MC. but we know that the slave is where the problem lies with THESE cars... .. I can't seem to get them to change their approach. Now I can understand that they don't want to have to charge me any more than they need to with unnecessary repairs--They're a good shop. I told them what's going to happen.... They'll look at the master, bleed the system, pronounce the problem fixed, and in few months I'll be back with the same problem. Maybe then they'll believe?

This is NOT true. I've been thru the Slave Cylinder drill when I had only 32,000 miles on my 2019 FiST. No leaking fluid at all, what was the problem was the clutch pedal stuck close to the floor and lifting it up did NOTHING to solve the problem, it would go right back to the floor the next time the pedal was pushed down. Mine had been "sticking for 4 weeks" and I had reported this issue twice. The dealer told me to bring it back when it's would return to the up position. Which happened when I was heading home from work and it stuck down about 3 miles for the dealer. Did a loop on side streets to get turned around and nursed it to the dealer by keeping it in 3rd gear and timing the lights. Took a full month before they could get their Transmission Tech to work on it and the end result was that the shaft seals had basically melted to the slave cylinder shaft and that increased drag is why the pedal was sticking. I also learned that the manual transmission 2.0 L Mustangs were having the exact same issues.

As for the cause, it's the Chinesium Throwout Bearing used on the slave. I believe it's a Ball Type bearing and if one of balls has a tiny defect that will eventually caused damage to the bearing races and then more degradation of the balls. End result of this string of defects is HEAT, which is then transferred to the shaft of the slave cylinder. Get enough HEAT and those seals will melt. I do NOT like doing it but I now put the transmission in neutral at traffic lights to minimize the amount of time where the throwout bearing is engaged. So far that is working because my clutch still operates nice and easy. BTW, when I finally got my car back with it's new slave cylinder I did notice the force needed on the pedal was roughly 1/2 the effort needed when the slave cylinder was going bad.

Finally I will also note that if you don't have ANY fluid leak at the Master Cylinder I would suggest that you advise the shop doing the work on your car that you will NOT pay for any "diagnostics" that don't yield actual evidence of a problem with your Master Cylinder.[/QUOT

I do NOT like doing it but I now put the transmission in neutral at traffic lights to minimize the amount of time where the throwout bearing is engaged.
You should ALWAYS do this. I was taught this 57yrs ago when I was learning to drive. I have done it ever since and never had any clutch problems on any of my cars.