Clutch Master Or Slave?

[u/7LayerDip]

Clutch pedal is sticking, what do you guys think, is it the master or the slave cylinder? Or is it even possible to tell from this video? Follow up video from a few seconds later is in the comments

[u/mscott8088]

This happened to me this summer. They replaced the clutch pedal master cylinder. That solved it. They recommended doing that first anyways. If it didn't fix it, then it would be slave cylinder in the trans. Then while they have the Trans pulled, might as well service the whole clutch. Most of the cost is in the labor.

[u/7LayerDip → u/mscott8088]

Fortunately my warranty is good for another 20,000km so they'll be covering it, i may get them to change the clutch while they have the transmission open if they decide to change the slave and not the master

[u/ratherabeer → u/mscott8088]

Same, replaced the clutch master. I am worried about a slave cylinder going out. If it does, LSD and RS clutch going in while trans is out.

[u/OdinWolf17]

[u/disturbed286 → u/OdinWolf17]

I've never seen that version of the meme, but it's perfect.

Save, maybe, for the absence of Cpt Slow

[u/DragonVKx → u/OdinWolf17]

🤣🤣🤣

[u/Zestyclose_Ad286 → u/OdinWolf17]

image went through AI so much, the colors cease any contrast

[u/Snooka42]

Had same Symptoms recently was the slave master. Edit: was the one NOT in the Transmission Bellhousing. Got the wird's Mixed up from german.

[u/7LayerDip → u/Snooka42]

Fuuuck this is not what I wanted to hear but is likely the reality of the situation. Thanks.

[u/Snooka42 → u/7LayerDip]

I do think it could be either. If I am correct slave would be "better", since its cheaper to replace and not a transmission out job.

[u/7LayerDip → u/Snooka42]

From what I was seeing online the master is fairly easily accessible but the slave is inside the bell housing

[u/gbchaosmaster → u/7LayerDip]

That’s right. The master is the larger cylinder right behind the pedal which pushes fluid through the line into the smaller slave cylinder in the transmission to generate a large amount of hydraulic force.

If your slave went out… congratulations, you’re getting a brand new clutch too!

[u/7LayerDip → u/gbchaosmaster]

Or not lol, looking like it'll be a warranty repair

[u/_mk451 → u/7LayerDip]

I would rather drop the tranny than get to the master on an ST.

[u/Snooka42 → u/7LayerDip]

Ah shoot, than I mixed those two up, sorry about that. Gibt those mixed up from the german counterparts.

[u/fryerandice → u/Snooka42]

Master is the easy one, that's the whole clutch pedal assy. It's a PITA to DIY but it's "easy".

Slave is the the transmission out job, that's the one that's pushing the TO bearing.

[u/bagsofholding → u/Snooka42]

The slave is the one in the trans so it's basically a clutch job. It's included with clutch kits and people rec the rs slave over the st slave because it's metal

[u/bchiodini]

It could be either. Check for brake fluid at the weep hole at the bottom of the bell housing and check for brake fluid around the push rod at the top of the clutch pedal assembly.

Is your brake fluid reservoir full? The clutch draws from relatively high up on the reservoir.

[u/Commercial_Low_6979 → u/bchiodini]

Master can fail externally with fluid near your foot or internally with no leak. Slave will leak out the weep hole. If there’s no leak anywhere, I’d vote master. If the weep hole drips fluid, then slave. I’ve had both failures at separate times in the last year on my ST.

Master swap is far easier than slave.

[u/7LayerDip → u/bchiodini]

Reservoir is full, nothing at the top of the clutch pedal, I haven't been underneath the car to check the bell housing yet

[u/H0rnyJesus]

It really could be either..

[u/7LayerDip → u/H0rnyJesus]

I'll also add that there is no fluid or leaks on the master that I can see

[u/Life_Telephone_1578]

That happened to mine at 100,052 miles on my car. Replaced clutch and master cylinder. Good to go

[u/toastedoats-]

Air is getting in somewhere. These slaves are piles of shit, check the line from the master cylinder to the slave. The slave has a nipple on it too, make sure that's still attached and not letting air in. Make sure the tube isn't leaking air where it connects to the slave cylinder. More than likely, it's leaking there. If you recently did a break job, you could have sucked air in as well. All I know is, that's what air in your shit looks like. It's only from that pedal to the master to the slave you gotta worry about. Take your airbox out and have a gander, peace of cake. This picture shows the piece of garbage I'm talking about. Should see it mounted with that T facing down into your slave cylinder and transmission right below the air box. Most Ford quality item they put in these things.

[u/Death_Hazard]

I just fixed this problem when I hit 100k miles. Had to replace the whole clutch wasn’t to bad to be honest

[u/Less_Clerk_6048]

Make sure your brake fluid is topped off since your clutch uses the same fluid as your brakes. Had this happen to me and all I had to do was fill the reservoir up a little and bleed the clutch. Good as new

[u/KungFuActionJesus5]

Bleed it first. If the issue persists, change master. If it continues more change slave.

[u/7LayerDip]

And the follow up video from about 10 seconds later

https://reddit.com/link/pgjatjz/video/dw28hx395avh1/player

[u/ClassikD → u/7LayerDip]

I just appreciate you posting a video doing actual troubleshooting work. You're def on the right track unfortunately :/

[u/7LayerDip → u/ClassikD]

Thanks, I figured providing as much information I can would help with diagnosis

[u/GothDaddymusic]

Check behind battery box make sure there is no leak. Also is there a leak on the clutch pedal up top?

[u/Toby_7243]

My RS did this not long after buying it… it was the slave cylinder. Had a new clutch fitted at the same time just because they were that deep into the gearbox…

I think the labour alone would have been £800 from Ford would the car have not been under warranty. Good luck OP!

[u/7LayerDip → u/Toby_7243]

Dealer Diag says it's the master and will be covered under warranty, I have a funny feeling that they're going to change the master and that the issue will still persist but we'll see, the part should be installed tomorrow morning

[u/Responsible_Virus772]

Bro I just got my car towed today by the same exact problem, now I know it is my slave cylinder because after it broke there was a puddle of brake fluid underneath the car, I went to a Ford dealership and buy an RS slave cylinder that's made entirely metal (ST is plastic and more weaker) if you are replacing the slave cylinder, I also suggest to replace the clutch as well as a preventative maintenance, yeah it's more money but not as much as buying another car (plus you will make it more reliable with more strong parts)

[u/Commercial_Low_6979 → u/Responsible_Virus772]

This. Also did the RS slave upgrade. Clutch often gets doused in fluid when slave fails, too. More reason to swap it. There are numerous other ”while you’re in there“ items, but these should be based on mileage/condition.

[u/Somerockenguy]

Probably the slave. Mine failed at 160k, 6 years. Replace it with the RS one as it's metal. Think about doing the clutch and fkywheel while the transmission is out. 

[u/irishOpinion]

Slave, I had this same situation 5 months ago. Don't forget to change pressure release bearing like I did. Now I have to open it all up again. FML

[u/FocusSTx91]

Clutch spring “perch” replacement needed.
Look up “Steeda Focus ST/RS Clutch Spring Assist and Spring Perch Kit” from steeda or summit Racing, or wherever else you buy parts. Yes - it’s so expensive 90$. But it’s works well & goes in easy, under 5 min. If your current spring perch is not broken, then sorry it would be the slave or master issue.