McLeod Clutch Issuse

[12MustangGT302]

Hello All, First-Time Poster Here...




I'm having an issue with a clutch/flywheel/throwout bearing combination that I had installed in July of 2021.

I purchased a Super Street Pro Clutch Kit (p/n 75253) for my 2012 Mustang GT,
Along with their Aluminum Flywheel (p/n 563408) & Throwout Bearing (p/n 12).
I had Stainless Steel Clutch Line and new ARP Bolts Installed as well.

I had it professionally installed at a good shop over 1 year ago and roughly 10k miles...
In that time, I've have had no issues whatsoever; clutch feel & operation have been fantastic.

Until this past weekend with car being driven aggressively on some mountain roads...
After pulling over without any issues, and the getting ready to set off again,
Upon depressing the clutch, and trying to select a gear,
The shifter was extremely difficult to get into 1st gear (or any other gear)
Upon shutting off the engine, the shifter 'feel' immediately returns to normal.

It feels as though the clutch is not fully disengaging at any rpm level now,
even with the clutch pedal depressed fully to the floor.
It is still drivable, but the clutch lever effort is extremely high between shifts,
and the shifts must be done very slowly (allowing rpm to match gear speed).

The clutch pedal does feel different during operation, the 1st 1/3 of pedal travel feels very soft.
It only starts to feel tight around the 2/3 -3/3 range of the pedal.

The clutch still grabs hard still and holds power as normal.
The clutch is not making any new or different noises.

The brake fluid had been changed in the spring of this year, and the level has remained constant.
There does not seem to be any brake/clutch fluid leaks around the master cylinder or clutch line.

I have tried to 'prime' the clutch system to remove any air trapped in the system,
by pumping the pedal 100X or so with no change.

I am trying to identify what the problem could be.
Is there any help you could offer in diagnosing this?

I did try searching for issues of this nature, but nobody seems to have the same issue after 1yr/10k miles of correct operation,
It always seems to be AFTER an installation or maintenace event.

Thank you all!

 

[EF1]

It sounds like the clutch isn't fully disengaging, which is most likely the slave cylinder. If it isn't leaking, check the master cylinder. It may not be building enough pressure to fully activate the slave.

 

[TMSBOSS]

I had a similar issue. I bought both slave and master cylinders. This seemed to fix my problem. I do my own work so dropping less than $200.00 on parts didn’t hurt too much. I could have changed just the master and likely solved my problem. I guess we will never know now. Lol
Your problem does sound more hydraulic.
What fluid have you been using in your clutch?

 

[12MustangGT302]

I had a similar issue. I bought both slave and master cylinders. This seemed to fix my problem. I do my own work so dropping less than $200.00 on parts didn’t hurt too much. I could have changed just the master and likely solved my problem. I guess we will never know now. Lol
Your problem does sound more hydraulic.
What fluid have you been using in your clutch?

Car is 10+ Years old now with 112k (spirited) miles on the clock so some components ***could*** be starting to show their age I suppose.

You mean you changed out the CLUTCH Master Cylinder, correct? Not the BRAKE Master Cylinder? 2 Separate Components.

And the Slave Cylinder is inside the Transmission [Bell Housing] Correct? Essentially the same thing as the Throw-Out bearing?

I did flush the brake lines in the spring, and subsequently was topping off the brake fluid reservoir with OEM Motorcraft DOT 3 Fluid.

 

[TMSBOSS]

Yes, clutch slave and master cylinder.
I did run Castrol synthetic brake fluid in both the clutch and brakes. I separated the two systems a few years back. I now run Ford DOT 4 fluid in the clutch and the Castrol in the brakes. There are a few posts stating the Castrol can be hard on the seals in the cylinders. With the Castrol costing north of $75 a liter and flushing the system every season, separating the two systems was a no brained for me. I wish I had done so earlier.
Are you from the city, burbs or out in the sticks? I was born and raised In northern Illinois.

 

[Alex_murrica]

I had the same issue with an RST. The pressure plate warped; you could see it with a straight edge. Sent back to McLeod and they warrantied it. They said it “wasn’t intended for track use and the extreme conditions caused it to fail.” I’ve since switched to an Exedy.

 

[12MustangGT302]

Yes, clutch slave and master cylinder.
I did run Castrol synthetic brake fluid in both the clutch and brakes. I separated the two systems a few years back. I now run Ford DOT 4 fluid in the clutch and the Castrol in the brakes. There are a few posts stating the Castrol can be hard on the seals in the cylinders. With the Castrol costing north of $75 a liter and flushing the system every season, separating the two systems was a no brained for me. I wish I had done so earlier.
Are you from the city, burbs or out in the sticks? I was born and raised In northern Illinois.

I ordered a new Clutch Master Cylinder, [the higher capacity GT500 Version], the Shelby Remote Clutch Reservoir, and the McLeod SS Clutch Line with the small bleeder option.

I think I'll try some fresh Ford DOT4 in the (newly isolated) clutch system, and bleed the system as best as possible.

I was born and raised in the west suburbs. Went to Bartlett High School, Elgin Community College & NIU.

Thanks for the inputs.

 

[12MustangGT302]

I had the same issue with an RST. The pressure plate warped; you could see it with a straight edge. Sent back to McLeod and they warrantied it. They said it “wasn’t intended for track use and the extreme conditions caused it to fail.” I’ve since switched to an Exedy.

I'm "hoping" to not have to drop the trans... I'm going to try the few things listed above first. If that doesn't do it, then the issue must be inside the thing... but I have also not TRACKED the car by any means. 'Aggressive street driving' isn't in the same league as full-on track days - IMO.

 

[TMSBOSS]

I was born and raised in the west suburbs. Went to Bartlett High School, Elgin Community College & NIU.

I was Born in Elgin, raised in Batavia, Geneva and Elburn. Joined the military and traveled a bit. Came home and built a home near Rochelle. The Tri-Cities seem to be just an extension of Chicago now. Kind of sad to see the change/growth.
Separating the two systems is always a good idea. Cost of a good quality fluid that has to be cycled to flush in the clutch can be expensive. I also find black residue in the clutch fluid, likely from the clutch disc then migrating into the fluid. You would not think the residue would make it through the system, but it does.

Welcome to the site and the sport.

 

[EF1]

I ordered a new Clutch Master Cylinder, [the higher capacity GT500 Version], the Shelby Remote Clutch Reservoir, and the McLeod SS Clutch Line with the small bleeder option.

I think I'll try some fresh Ford DOT4 in the (newly isolated) clutch system, and bleed the system as best as possible.

I was born and raised in the west suburbs. Went to Bartlett High School, Elgin Community College & NIU.

Thanks for the inputs.

The McLeod bleeder valve was a waste of money for me. It really wasn't useable on the MT82 due to where the clutch line entered the bell housing.

 

[2012-Boss]

I wouldn’t install the GT500 clutch master - it might cause the slave cylinder to over throw and fail prematurely. If you are worried about the clutch master, replace it with the correct part for your car.

 

[12MustangGT302]

The McLeod bleeder valve was a waste of money for me. It really wasn't useable on the MT82 due to where the clutch line entered the bell housing.

I'll give it a try... I contacted Mcleod about this and it was directly recommended to me by them.
But I do suspect that you are correct, so If I can get it, I'll try to return it to them for a refund.

 

[12MustangGT302]

I wouldn’t install the GT500 clutch master - it might cause the slave cylinder to over throw and fail prematurely. If you are worried about the clutch master, replace it with the correct part for your car.

Interesting... My understanding was that the '13-14 GT500 clutch master is a fine upgrade for the '11-14 GT's? That their *fluid capacity* and fluid pressure is the same as on the GT unit, the difference being that the housing is made of metal on the GT500 unit and plastic on the GT's.

 

[mwjscn]

GT500 clutch master has a larger internal bore of 13/16" while the GT is 3/4". It was a change for the 2013-2014 model year, where the earlier cars also seemingly shared in the plastic design. While many people say it works well, and I'd also like to try it, you never see any long term reports from people who have installed them in the past. However, some do note that the clutch stop should be shimmed out during install, which would help prevent any over-traveling issues.

 

[67GTA]

I would bet money it’s the McLeod slave cylinder that failed. American Muscle was the first site that came up when I Googled the McLeod part number - just wanted to look at a picture to compare it to the Ford OE unit. They look very similar - likely made by the same supplier. In looking at the reviews and customer install photos, a lot of examples of slaves that failed due to being overextended.

I strongly recommend this simple device from Maximum Motorsports for any aftermarket clutch install on the S197 Mustangs. Install requires removing the pedal box from the firewall, so might as well replace the master cylinder at the same time.


https://www.maximummotorsports.com/Adjustable-Clutch-Pedal-Stop-2005-2014-Mustang-P1470.aspx

For the master cylinders, as has been mentioned, I would recommend keeping the master cylinder matched to the slave. My experience is the inverse of what you’re doing; I installed the 13-14 GT500 slave cylinder on my Tremec (with Kohr spacer) and disengagement just wasn’t crisp at higher RPMs. I changed to the bigger bore GT500 master pictured above and the system works perfectly now.

 

[12MustangGT302]

So I got the installation done, and system bled yesterday.
And that did it, the clutch and shifting operation feels better than ever.



I KNOW DEFINITIVELY the Clutch is fully disengaging now.
...While I still had the car in the air, up on the jackstands, I started it up,
...had the transmission in 1st gear, and with the clutch fully depressed,
...there was -ZERO- rotation on the rear wheels.



Everything feels as it should, the shifts at high-rpm are solid and crisp.
I also got my Clutch Fluid Remote Reservoir Installed.



Cheers everyone, thanks for the good insights and help!

 

[TMSBOSS]

Did you install a clutch pedal stop like the one 67GTA mentioned?
I have an auto blip and found myself “Shirt Stroking” the clutch pedal. The stop allows the stroke to be shorteNed along with the engagement of the clutch position switch. This is handy if you are running an auto blip with the RST.

 

[12MustangGT302]

Did you install a clutch pedal stop like the one 67GTA mentioned?
I have an auto blip and found myself “Shirt Stroking” the clutch pedal. The stop allows the stroke to be shorteNed along with the engagement of the clutch position switch. This is handy if you are running an auto blip with the RST.

No, but I was considering it. No Auto-Blip Currently.