2012 Slave Cylinder Question

[Paul Dube]

So some background...
My car is a 2012 PP with factory clutch and 9,000 miles on it.
I've had the car for 4 months now and it drove perfect. Only issue I've had with the clutch was some burning smell when caught in stop-and-go traffic on a mountain road (going uphill) when the car was new to me at 7,000 miles.
Since then, nothing.
First a little bit at around 3,000 rpm then full slip after a few pulls. I came back home and the car would barely advance in gear without slippage. Burnt smell again. Did the final test of 4th gear at a stop with the brakes on and the car did not stall.
Clutch change time...
So, I pull the clutch and although very dusty with clutch dust, it looked good. No real hot spots and both discs looked good, not glazed or cracked etc.
I put in an RXT with new Ford Slave and it's good to go now.

Only question is:
Is it possible that the Slave was failing, causing the slippage?
I did notice that the release point on the peddle was right at the top of travel.
Any insight into this?

My RXT was purchased used and rebuilt by Mcleod, but the previous owner had it for only 1,000 miles and it started slipping the same as my factory clutch - after mods on the dyno. The clutch still looked good, with just minor hot spots and both discs looked good not shiny.

Just seeing these two examples of clutch slipping made me think...

 

[Snoopy49]

The slave would have to be binding or have a restriction in the fluid line, this would prevent it from retracting properly.

 

[RedVenom48]

If you have the old slave, carefully stretch it and see if it feels like its binding.

I suspect you just had a glazed clutch. Once a friction material like a clutch or brakes get THAT bad, its been extremely overcooked all the way through. Its coefficient of friction has been permanently modified.

 

[tktlwyr]

I had dealt with what seemed to be slave cylinder issues for the last 8 years. The car always crept forward when in gear with the clutch pressed. The factory clutch was good when the slave failed at 65,000 miles.

I installed an RXT sprung hub while the transmission was out to install a new slave cylinder. I also installed a braided steel line at that time. That clutch also crept and expired in 20,000 miles. The mechanic mentioned what a bitch it was to bleed. I put in a second RXT sprung hub that crept and expired in 12,000 miles. The last time it expired was also on a dyno for a Lund tuning session. Luckily, the car was at Power By the Hour in Palm Beach.

PBH upgraded any clutch part that the factory updated but also had an issue bleeding the system. I gave the OK to change the master cylinder and that seems to have done the trick. The pedal feels smoother than it ever has and the pedal pressure is excellent where it has always felt stiff in the past.

Good luck with your repair!

 

[MADRUSSIAN]

I had dealt with what seemed to be slave cylinder issues for the last 8 years. The car always crept forward when in gear with the clutch pressed. The factory clutch was good when the slave failed at 65,000 miles.

I installed an RXT sprung hub while the transmission was out to install a new slave cylinder. I also installed a braided steel line at that time. That clutch also crept and expired in 20,000 miles. The mechanic mentioned what a bitch it was to bleed. I put in a second RXT sprung hub that crept and expired in 12,000 miles. The last time it expired was also on a dyno for a Lund tuning session. Luckily, the car was at Power By the Hour in Palm Beach.

PBH upgraded any clutch part that the factory updated but also had an issue bleeding the system. I gave the OK to change the master cylinder and that seems to have done the trick. The pedal feels smoother than it ever has and the pedal pressure is excellent where it has always felt stiff in the past.

Good luck with your repair!

What did they replaced factory slave cylinder with? Another oem unit or aftermarket?

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[MADRUSSIAN]

Sorry, not slave but master is what meant

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[Catmonkey]

I don't think there are any aftermarket alternatives for the clutch master cylinder yet, but the 13-14 does have a larger diameter and should push more hydraulic fluid with the same movement of the clutch pedal. It requires removal of the brake and clutch pedal assembly.

 

[tktlwyr]

My car is a 2010 and the master cylinder was replaced with part number 9R3Z-7A543-A, which is 2007 through 2010 master cylinder.