Clutch issues


G

GTJeff

New member
May 19, 2024
2
I ran my 2005 GT on the track at Road America (Elkhart Lake) Monday (Aug 26). During the last lap, when shifting, my clutch pedal stuck close to the floor and failed to come back up. I was able to get my foot under it and get it back up. I had this happen a few times before I was able to get the car to the pits and let the car cool down. I made it home (about 60 miles) without any issues. I checked the clutch fluid reservoir and it was full. Could the problem possibly be attributed to the heat? The heat index on Monday was over 100° and the car was driven quite hard. Gtjeff
 
  • Like
Reactions: dreimer
Fairly common issue. Installing a trans cooler and putting heat sleave around the clutch line that runs by the catalytic converter will help. We have been doing this for years, and it will help. We believe that the fluid gets "boiled" since the line is so close to the converter/exhaust. And of course the trans cooler will keep the trans, cooler as well. :):)
 
  • Like
Reactions: Fast Freddy, 289 4spd, Nafod and 2 others
^^^ Well the one that knows best just chimed in, however I will add my 2c, as he didn't mention it, for my car, a fluid change solved this. I have used Castrol SRF, and Motul RBF fluids.
 
  • Like
Reactions: Nafod
They are both right. My god what is happening?
 
  • Like
Reactions: analogdesigner and Specracer
When you bleed it; reservoir will be about empty after 2 bleeds. Check and refill often. Suck the old stuff out, refill and bleed.
 
And there is a specific procedure for bleeding the clutch, which is not like the typical brake caliper. Refer to the shop manual, or let a pro like Rich or Rob or Kendall do it. Add your location to your profile so that someone can suggest a GT specialist near you.
 
There are two bleed areas, one in the middle of the firewall. And one down low on passenger side
 
  • Like
Reactions: analogdesigner and 69b302
Are you running the track with AC on? It is a good idea because the the fans come on earlier and helps prevent overheating.
 
As others have said, the issue is caused because the clutch fluid boiled. Fresh clutch fluid - especially if you use a high temp fluid, should really help to mitigate the occurrence. A transaxle cooler will also really help. The transaxles run at a very high temp anyway and when you put any kind of performance through them, they just can't dissipate the BTU's.

In normal clutch bleeding, you should never need to use anything but the bleed nipple at the transaxle. Be careful to initially crack that nipple loose as sometimes it is on so tight that the bracket just wants to bend.

I would NEVER recommend using the AC while on the track as you are just adding more thermal load to the system while simultaneously lowering the efficiency of the radiator by heating the AC condenser packaged just in front of it.
 
  • Like
Reactions: analogdesigner
I have a car that had a nice bracket to space the clutch line away from the exhaust down where it meets the chassis. Also the heat shield is a great idea and the better fluid as recommended above.
 
Brake fluid is highly suseptible to absorbing moisture. This can significantly lower the boiling point and cause your problem. Especially probable if you have not had the problem in the past and now mysteriously are having the problem under the same conditions.
Flush the old with new by bleeding at the transaxle. However, the fluid residing between the bleeder and the clutch slave will not flush. So......after flushing and driving for awhile, through osmosis and pumping the fluid, the new and old will mix with each other. So....flush again. And, repeat the drive flush process even again. You will see the old fluid flush out each time.
 
Last edited:
The book procedure says to step on the clutch pedal, then open the bleeder screw at the transaxle to let the fluid come out of the slave cylinder, then close the bleeder, then release the clutch pedal. Do that several times. Refer to the book.
 
I lost my brakes at Limerock due to not changing the fluid. It was very scary. Change every two years maximum.
Joe
 
I agree with the rest of the comments on this thread. Also one other extra additional help is to use dot 5.1 fluid. It has a higher boiling point and collects less moisture. I only use dot 5.1 on all GT services.

Joe
 
JOEA2 said:
I lost my brakes at Limerock due to not changing the fluid. It was very scary. Change every two years maximum.
Joe
Click to expand...
Bleed brake fluid before every track day, regardless of time.
 
GTJeff said:
I ran my 2005 GT on the track at Road America (Elkhart Lake) Monday (Aug 26). During the last lap, when shifting, my clutch pedal stuck close to the floor and failed to come back up. I was able to get my foot under it and get it back up. I had this happen a few times before I was able to get the car to the pits and let the car cool down. I made it home (about 60 miles) without any issues. I checked the clutch fluid reservoir and it was full. Could the problem possibly be attributed to the heat? The heat index on Monday was over 100° and the car was driven quite hard. Gtjeff
Click to expand...
Yep. The same thing happened to me at the last GT rally in Arizona. At the track day at Apex, coming into the pits at the end of one of the sessions the clutch pedal didn't return. I have long arms and did it manually. In the pits some of the other guys explained the issue and said it would be normal after a couple of minutes. It was. I also have the long tube headers and cat delete, so that may have added to heat in the area. At my service earlier this year I had Rich install the trans cooler.
 
  • Like
Reactions: Fast Freddy and extrap
You must log in or register to reply here.

Top Bottom