Took my GT to the track... Daytona Superapeedway Rolex 24 circut ! After about 8 laps I found that I had to help the clutch pedal return to the full up position... Fixed itself shortly after I came into the pits, never a problem on the street... any suggestions?
Clutch pedal not returning
- Thread starter Gastrux
- Start date
tmcphail
GT Owner/Vendor
fjpikul
GT Owner
Probably need a transmission cooler if you don't have one. See Kendall's website or get Ford product.
MR2Race
FGT The Velvet Hammer
FGT Clutch Pedal falls
FGT Clutch Pedal falls
We had a problem similar to this in prototype development.
It was quite difficult to Diagnose.
And had to make a minor design change to correct it.
It was an intermittent problem.
The clutch pedal would fall to the floor with out clutch disengagement.
It would only happen in a race track situation, (Never on the street).
Was that the case with your car?
Pedal fell with no disengagement of the clutch?
And then you pulled up the pedal with your foot.
Pumped the pedal & things seemed ok?
Let us know if that describes your experience?
If so- We know what has failed
As for a trans cooler fixing this problem. I’m not seeing the connection.
FGT Clutch Pedal falls
We had a problem similar to this in prototype development.
It was quite difficult to Diagnose.
And had to make a minor design change to correct it.
It was an intermittent problem.
The clutch pedal would fall to the floor with out clutch disengagement.
It would only happen in a race track situation, (Never on the street).
Was that the case with your car?
Pedal fell with no disengagement of the clutch?
And then you pulled up the pedal with your foot.
Pumped the pedal & things seemed ok?
Let us know if that describes your experience?
If so- We know what has failed
As for a trans cooler fixing this problem. I’m not seeing the connection.
BlackICE
GT Owner
Let me guess, clutch fluid overheated causing gas in the line, possibility exacerbated by old moisture laden fluid. I think I recalled someone posted that the exhaust plumbing is close to the clutch's hydraulic lines.
gtinmyblood
GT Owner
I had the same experience when I tracked my car, not this last time but the previous time. I was on track for 45 minutes running pretty hard. I actually heated up the clutch and brake fluids so that they coagulated in the lines. I since changed brake master, clutch master and went to a race rated castrol fluid. I also heat wrapped the lines in the engine dept to protect from heat.
MR2Race
FGT The Velvet Hammer
I would like to hear from GASTRUX .
Was his car acting like our car?
Pedal flops to the floor and stays down without the clutch disengaging the engine from gearbox?
And then you had to pop the pedal up with your foot. Then things seem fine.
Is that exactly what happened with you car GTINMYBLOOD?
When you had your problem?
Was his car acting like our car?
Pedal flops to the floor and stays down without the clutch disengaging the engine from gearbox?
And then you had to pop the pedal up with your foot. Then things seem fine.
Is that exactly what happened with you car GTINMYBLOOD?
When you had your problem?
fjpikul
GT Owner
Alex, when we did Rally II in CA, the guys with tranny coolers had no problems with their clutches in the mountain driving. Several guys without coolers did. Heat build up seems to be culprit, simple cause and effect.
If you know the answer, please let inquiring minds rest.
If you know the answer, please let inquiring minds rest.
BlackICE
GT Owner
Frank, you should have remembered your Stat 101. Correlation is not causation! Did you know that more than 99.99% of the people who died of cancer had a cold! Did the cold cause the cancer. What would a pathologist say? BTW, I never had any problems with my clutch and don't have a tranny cooler.
Last edited:
gtinmyblood
GT Owner
"Is that exactly what happened with you car GTINMYBLOOD?
When you had your problem?"
I was running the west track at Firebird in Chandler, Az. I had done a couple of session and run pretty hard. I was probably 40 minutes into the third session when coming into turn 1 at the end of the straight I went to hit the clutch pedal and it wasnt there. I ended up spinning out between turns 1 and 2. From then on I could get very little clutch. not enough to get reverse or 1st. When I took it in to ADS in chandler they asked why the fluids had jellied.
When you had your problem?"
I was running the west track at Firebird in Chandler, Az. I had done a couple of session and run pretty hard. I was probably 40 minutes into the third session when coming into turn 1 at the end of the straight I went to hit the clutch pedal and it wasnt there. I ended up spinning out between turns 1 and 2. From then on I could get very little clutch. not enough to get reverse or 1st. When I took it in to ADS in chandler they asked why the fluids had jellied.
fjpikul
GT Owner
Ice, there's lies, damn lies and statistics. Did you know that only 14% of smokers develop lung cancer? Maybe it offers protection. I've been at the track 3 times now, the last pretty hard for a total of 75 miles with no hint of clutch problems. The drive from Scottsdale to Vegas was without a hitch. Perhaps we need a poll. Hmmm
BlackICE
GT Owner
fjpikul
GT Owner
ThatPhilBrettGuy
GT Owner
It can do that without condensation in the fluid too. Some heat shielding around the clutch lines stops it. Doesn't seem to make any difference if there's a transmission cooler from what I've seen.
Known issue over here. I have to say it was worrying the first time it happened to me! I let it cool down and went out again with no issues.
Gill Jr.
GT Owner
At Rally III during the LVMS track day event I experienced the clutch pedal staying on the floor when I downshifted into second gear under hard braking going into turn 1. I had to lift the pedal back up with my foot. This was a very hot day and I was pushing the GT and myself to our limits. This had never happened before or since during street driving. I was told by Jamal and one of the SVT guys that during prototype testing they experienced the same symptoms and it was thought that it was due to the fluid in the clutch master cylinder leaking past a seal from the braking G forces. I was told that I could have the clutch master replaced under warranty, but I never did. Once I let the car cool down the problem went away and the clutch has worked fine ever since. I think the problem was heat related. At the time my GT was bone stock. Subsequently I have added a Cooltech trans cooler amongst other things (Thanks Kendall!), however I have not had an opportunity to track the car to see if the problem persists.
H
HHGT
Guest
This used to happen in my Z06 every time I tracked it. Got used to lifting the clutch pedal, made it back to the garage and let it cool down.
MR2Race
FGT The Velvet Hammer
You are correct GILL JR;
Kent Harrison and I discovered a hydraulic clutch phenomenon.
And because it was an intermittent problem it became one of the toughest challenges we had in FGT development. As none of the Ford or supplier Clutch specialist had seen anything like this, we were on our own to correct this deal.
It was nearly impossible to recreate the issue with normal testing. And you can not visually see or watch what is going on inside the bell housing.
So we felt as if we fixed this problem several times. Only to have it pop-up at latter date to haunt us yet again.
Short story (I will give you the long story at a latter date)(I am trying to get ready for an ice racing event this weekend).
The hydraulic clutch fluid in the long line needed for a mid-engine FGT.
Would (with the help of hard braking on a rough race track) develop enough inerthia.
To make its way back into the clutch master cylinder.
Actually drawing the CSC (concentric slave cylinder) away from the pressure plate.
Not a problem until it is time to shift gears. You would stab at the pedal.
And no one was home, the pedal has an over center spring to assis you in normal clutch disengagement. But in this instance there is no pressure plate effort to overcome
(as the CSC is no longer near the clutch). So the slightest bump or nudge and the pedal is driven to the floor by the over center spring. And it stays down there flat against the mat.
The Final Fix:
We added a residual pressure valve inside the clutch master cylinder.
And my gut is telling me this poppet valve may be the cause our frustration.
But let’s not jump to conclusions just yet.
I’m thinking there must be a simple bench test to determine if it is working correctly.
Kent Harrison and I discovered a hydraulic clutch phenomenon.
And because it was an intermittent problem it became one of the toughest challenges we had in FGT development. As none of the Ford or supplier Clutch specialist had seen anything like this, we were on our own to correct this deal.
It was nearly impossible to recreate the issue with normal testing. And you can not visually see or watch what is going on inside the bell housing.
So we felt as if we fixed this problem several times. Only to have it pop-up at latter date to haunt us yet again.
Short story (I will give you the long story at a latter date)(I am trying to get ready for an ice racing event this weekend).
The hydraulic clutch fluid in the long line needed for a mid-engine FGT.
Would (with the help of hard braking on a rough race track) develop enough inerthia.
To make its way back into the clutch master cylinder.
Actually drawing the CSC (concentric slave cylinder) away from the pressure plate.
Not a problem until it is time to shift gears. You would stab at the pedal.
And no one was home, the pedal has an over center spring to assis you in normal clutch disengagement. But in this instance there is no pressure plate effort to overcome
(as the CSC is no longer near the clutch). So the slightest bump or nudge and the pedal is driven to the floor by the over center spring. And it stays down there flat against the mat.
The Final Fix:
We added a residual pressure valve inside the clutch master cylinder.
And my gut is telling me this poppet valve may be the cause our frustration.
But let’s not jump to conclusions just yet.
I’m thinking there must be a simple bench test to determine if it is working correctly.
Last edited: