Clutch Master cylinder replacement

[GregTheBastard]

Clutch pedal stuck to floor a couple times. Does anybody know where clutch master cylinder is and directions on how to replace?

 

[hawyee]

It's more than likely the slave not the master.

 

[arlisscm]

^^^ Unfortunately it's likely the slave cylinder failing (which the transmission needs to be removed to replace), but the master is in the cabin attached to the clutch pedal assembly. Disconnect the lines at the firewall then remove the clutch pedal assembly from the inside. If I recall its was around 3 nuts and an electrical connector. The tricky part for me was removing the plastic locking/hinge pin the holds the master to the pedal on the one side, had to get crafty with a zip-tie. If you want to try replacing the master just to make sure, its fairly cheap and easy, but likely not the problem.

 

[TDavis]

If you haven't tried already, bleed the brakes and clutch. Had same thing happen and bled my shit over a year ago and its been fine.
When I looked back, I never changed my fluid besides when I installed the BBK which was years and almost a dozen track days ago.

Dirtiest fluid came out of my slave.

 

[Zeille]

If you haven't tried already, bleed the brakes and clutch. Had same thing happen and bled my shit over a year ago and its been fine.
When I looked back, I never changed my fluid besides when I installed the BBK which was years and almost a dozen track days ago.

Dirtiest fluid came out of my slave.

I'd like to add that the best interval to flush the fluid out is 30k mi... It's my understanding that the premature slave cylinder failure is mostly due to improper use OR old fluid. At 156k, my stock slave cyl is holding like a champ.

 

[Capri to ST]

I'd like to add that the best interval to flush the fluid out is 30k mi... It's my understanding that the premature slave cylinder failure is mostly due to improper use OR old fluid. At 156k, my stock slave cyl is holding like a champ.

That's helpful to know that keeping fresh fluid in there may help prevent premature slave cylinder failure. This makes sense, because as most people know brake fluid attracts water. Even if it looks okay after a time there is significant moisture in the system which can clearly make premature failure more likely.
I've been getting the brake fluid flushed every two years and getting the clutch fluid flushed every 4 years. I don't think the manual has a recommended interval for either one of those, these are intervals that were recommended to me by a trusted mechanic. That may be more often than it's needed, but since the brakes are obviously the most important safety system on the car, I would rather be on the safe side.

 

[Zeille]

That's helpful to know that keeping fresh fluid in there may help prevent premature slave cylinder failure. This makes sense, because as most people know brake fluid attracts water. Even if it looks okay after a time there is significant moisture in the system which can clearly make premature failure more likely.
I've been getting the brake fluid flushed every two years and getting the clutch fluid flushed every 4 years. I don't think the manual has a recommended interval for either one of those, these are intervals that were recommended to me by a trusted mechanic. That may be more often than it's needed, but since the brakes are obviously the most important safety system on the car, I would rather be on the safe side.

yep. i don't think the manual outlines any sort of interval for brake fluid. however, it gets dirty over time and just isn't great to keep that filth in. good news is - most of the filth (based off my situation - before i did my clutch pedal) travels up into the reservoir. so, it's easy to pull a majority of the crud out before forcing clean fluid in.

 

[scooter123]

I purchased my FiST in 2019 brand spanking new. In October of 2020 the clutch pedal started sticking to the floor with 30K miles on the clock. One day driving home from work it stuck to the floor so I turned around and nursed it to the Ford dealer that sold me the car. Long story short it was a bad slave cylinder and this particular Chinesium Slave cylinder has a reputation for being problematic in the Fiesta ST, the Focus ST, and the Mustang. After talking to the tech and examining the slave cylinder out of my car we both came to the same conclusion, it had over heated. So what will overheat a Slave Cylinder. How about the throwout bearing attached to the shaft. Funny thing about ball bearings, if they have a really tiny defect it won't be felt when you test the bearing but when spinning it will generate more heat. Hot bearing means hot cylinder shaft and when it gets hot enough those seals get reformed and create drag on the shaft.

Lesson learned here is that I now do something that at one time I was taught to NEVER do. That is when I stop for a light or traffic I pull the transmission into neutral and let out the clutch. Because when these cars are out of warranty the cost for removing and re-installing the transmission is roughly 1600-1800 US Dollars.

 

[TyphoonFiST]

The Clutch master is on the clutch pedal itself* There is a great video on how to replace it. When i put in my New transmission ...i also installed a Brand new Fomoco Slave and had issues. SO i went ahead and replaced the Master instead of taking the Trans all the way back out. Been 20k+ miles and no issues whatsoever. But like other have said try bleeding the fluid first Via reverse bleed or Motive Power bleeder.

 

[akiraproject24]

If it ends up being slave, look into the RTS slave cylinder whoosh sells. Not a lot of info out there on it but it could possibly be an upgrade to the FOMOCO

 

[rexnebula]

Yeah I really wish someone had feedback on the RTS slave cylinder. I'll be adding an LSD next year and replacing the clutch and slave cylinder at the same time. Not sure whether to get the OEM or the RTS because of lack of feedback on the latter. My OEM slave cylinder with 90k miles on it sticks to the floor after 2-3 hours of continuous highway driving. Can lift it back up with my toe and if I pump it things will go back to normal for a few minutes, but I figure might as well replace it when I open up the transmission.

 

[TyphoonFiST]

Yeah I really wish someone had feedback on the RTS slave cylinder. I'll be adding an LSD next year and replacing the clutch and slave cylinder at the same time. Not sure whether to get the OEM or the RTS because of lack of feedback on the latter. My OEM slave cylinder with 90k miles on it sticks to the floor after 2-3 hours of continuous highway driving. Can lift it back up with my toe and if I pump it things will go back to normal for a few minutes, but I figure might as well replace it when I open up the transmission.

I have one in My Colby Clarke Transmission * No complaints as of yet* No difference in pedal feel or anything either.

 

[rexnebula]

I have one in My Colby Clarke Transmission * No complaints as of yet* No difference in pedal feel or anything either.

Good to know, thank you!

 

[ShaunPanday]

Hi guys, any tips on removing the hydraulic hoses from the clutch master cylinder, have a feeling i need to replace the master, saw a few videos which removed the wiper cowl and lights. There must be a easier way, can i remove the master then take off the pipes from inside the car

 

[TyphoonFiST]

Hi guys, any tips on removing the hydraulic hoses from the clutch master cylinder, have a feeling i need to replace the master, saw a few videos which removed the wiper cowl and lights. There must be a easier way, can i remove the master then take off the pipes from inside the car

NOPE* You need to access the lines from the engine bay into the firewall to the Clutch Master. Taking the cowl off* Wipers off and battery and the Tray put makes it 10x easier than trying to work around stuff.

Great Video*

View: https://youtu.be/-1AGBuwuzVg?si=5ht2HCEOeHKImG9m