1st long Freeway Run = hard clutch?

[Miker]

So I had to run up the mountains into Oregon for a dentist appointment today. 275 mile round trip. It was 95 in the valley but a pleasant 70 in the mountains. This was the first time I have driven the 2005 Mustang on the freeway. I had the cruise set at 80, AC on and it pulled on the hills effortlessly.
On the way home I noticed the clutch pedal had gotten much stiffer but still worked fine. I mean like triple the effort. Normally it seemed the clutch pedal was fairly light at first and then even lighter as it swung through its ark. Now it seemed much harder from the top to the floor. I have read others have had this problem but i didn't find any definitive answer. I'm sure it is heat related. Anyone here had this problem and found the fix?

 

[Dino Dino Bambino]

If anything, the clutch pedal would go softer if the clutch fluid was hot enough to form air bubbles in it. It's more likely that the clutch friction plate is nearing its wear limit.

 

[86GT351]

If anything, the clutch pedal would go softer if the clutch fluid was hot enough to form air bubbles in it. It's more likely that the clutch friction plate is nearing its wear limit.

Correct

 

[Juice]

How many miles on clutch?
As these clutches wear, pedal effort will increase. Usually accompanied by difficult shifting and difficult to put into reverse.
Could be just a throwout bearing/slave cylinder issue.
Either way, trans gotta come out.
Sorry

 

[Dino Dino Bambino]

As these clutches wear, pedal effort will increase. Usually accompanied by difficult shiting and difficult to put into reverse.

Ouch. Sounds like the OP might need a clutch laxative!

 

[Juice]

Ouch. Sounds like the OP might need a clutch laxative!

Foreign grammar police. That would be spelled with two T's man.

 

[Miker]

30K on a ford OEM clutch. The clutch works fine, no chattering or slipping. I agree that it seems it would be soft if the fluid was boiling but it has to be related to heat as it does not do it when driving local. There are many threads on the web about it but I have not found anyone who posted back with a solution. I am doing the brakes soon so at that time I will change out the fluid so at least that will be fresh. However how do you get fresh fluid to the slave cylinder?

 

[86GT351]

30K on a ford OEM clutch. The clutch works fine, no chattering or slipping. I agree that it seems it would be soft if the fluid was boiling but it has to be related to heat as it does not do it when driving local. There are many threads on the web about it but I have not found anyone who posted back with a solution. I am doing the brakes soon so at that time I will change out the fluid so at least that will be fresh. However how do you get fresh fluid to the slave cylinder?

30K on the clutch. However an 05 car so it is how old? Time is a factor also.

 

[Miker]

Clutch was put in in 2012. Also a new long block at the same time. Although I am not quite sure but it might have been operator error. I had the seat bottom in the fully down position why cruising. Usually it is closer to the top. I may have been pushing on the arm above the pedal. It happens to me sometimes even with the seat up. So with it down in the back the angle would promote my foot being higher when pushing the clutch. I'm 6'4" with size 13s so there isn't much room down at the pedals. I have hit the gas while braking a few times. That will get your attention!
I did check the fluid. It is pretty dark so I will change it with the brakes. I am assuming that the fresh fluid will eventually get mixed in with the fluid for the clutch slave as I don't see anyway to bleed it.

 

[86GT351]

So then if you are accidentally driving with your foot on the pedal, then you could be overheating the clutch itself.

 

[Miker]

No, not doing that at all. I think it's fine I just drove it and pushed on the pedal and it feels normal. Pushed on the arm and it felt hard = zero leverage.

 

[Midlife Crises]

This happened to me last summer. Cruising around town, slowly with lots of traffic. Temperature in the mid 80s. Very hot for Fairbanks. My breaks failed. The pedal was solid and pressing down hard would only slightly slow the car. The clutch pedal was also noticeably stiffer to push but still worked. I pulled into a parking lot and popped the hood to have a look. Nothing wrong but man was it hot in there. The engine did not overheat. Set there for about an hour watching the town while things cooled down. After it cooled I drove it home normally. Everything was fine. I think the break fluid could not handle the heat so I replaced all the fluid I could pump out. It has not happened again.

 

[Dino Dino Bambino]

Foreign grammar police. That would be spelled with two T's man.

I know but the opportunity to add a bit of humour was too good to miss.

I did check the fluid. It is pretty dark so I will change it with the brakes.

Good eye deer.
Fresh fluid in the clutch & braking systems can only be a good thing.

 

[Lime1Gt]

More than likely it's the clutch slave cylinder. I changed out my previous 05's when the pedal travel resistance increased to an annoyance. Can't remember exact mileage but traded in on a 17 at around 90,000 kilometers; I'll estimate 60,000 km's.
https://www.rockauto.com/info/797/LK_5100195100_Fro.jpg