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'Funky" clutch pedal after track session

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This past weekend at Summit Point a couple of times my clutch pedal sort of went limp (lot of free play) in the paddock right after coming of the track. After pumping pedal a couple of times it was normal. Never had a problem on the track but it happened twice right after coming off the track. Heat soak cooking the fluid at the clutch? I have not tried the bleed procedure using a vacuum pump on the MC. Maybe I'll try that with the next fluid change.
 
Chuck,

Good to hear your getting a bunch of track time.

I've never had the problem you described, but I did bleed my clutch with a vacuum bleeder and noted that clutch engagement occurred noticeably higher on the pedal stroke meaning I must have had air in the line all along. Procedure was pretty easy. I used a number 8 rubber stopper to seal the master cylinder and drilled a hole about the size of the hose on the vacuum kit.

Not sure what's going on, but maybe your getting an air bubble when the system gets hot then it might be working itself out after a few strokes of the pedal. I wouldn't think that the high temp brake fluid would be boiling at the clutch, but you never know.
 
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Thanks for the info. Looks like I need yet another part to make my Boss track-worthy. Only parts I ever needed on a Porsche to make it track worthy are tires and brake pads. Don't get me wrong...I LOVE my Boss but regardless of what Ford says it is NOT track ready as delivered. However, since it easily turns laps equal to Porsches costing 3 times as much I guess I can give Ford a pass and spend a few bucks on some parts. MGW shifter and Steeda springs next.
 

Justin

Save the dawn for your dishes!!!
ChuckP said:
Thanks for the info. Looks like I need yet another part to make my Boss track-worthy. Only parts I ever needed on a Porsche to make it track worthy are tires and brake pads. Don't get me wrong...I LOVE my Boss but regardless of what Ford says it is NOT track ready as delivered. However, since it easily turns laps equal to Porsches costing 3 times as much I guess I can give Ford a pass and spend a few bucks on some parts. MGW shifter and Steeda springs next.
throw this in the mix as well. http://www.latemodelrestoration.com/item/JHR-8025/Mustang-Jhr-High-Volume-Clutch-Line
and the boss ls scoop is a good idea as well
http://www.latemodelrestoration.com/item/M5025MBR/Mustang-Ford-Racing-Boss-302-Transmission-Cooler-M-5025-MBR
 
Pump it a bunch of times between sessions, like 50. I was having it only come up half way, and had to keep bleeding it. I removed the spring, have not driven it aggressively since then but it seems to be working better.
 
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Just ordered the JHR clutch line. At the PCA HPDE event dinner this past weekend I won a free 4 wheel alignment and corner balance from one of our local shops. Not very useful on my Mustang and right now my Porsche is in Tampa. However, it just so happens one of the owners of the shop is also a Mustang guy. He owns an '07 GT500 and his wife drives a 2010 GT convertible. He said he would be happy to provide an equivalent dollar amount of labor on the Boss. So I'll let him install the shifter, springs and clutch line. I figure my credit should cover about 1/3 of the labor cost. Hope to have it done before VIR Labor Day weekend but MGW shifter may not make it here in time.
 
Way cool, Chuck. Nice jesture by that shop owner. Good to know there are still guys out there like that. Let use know how the line and shifter work on the track.

Mike
 

PeteInCT

#LS-378 - So many Porsche's, so little time....
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ChuckP said:
Just ordered the JHR clutch line. At the PCA HPDE event dinner this past weekend I won a free 4 wheel alignment and corner balance from one of our local shops. Not very useful on my Mustang and right now my Porsche is in Tampa. However, it just so happens one of the owners of the shop is also a Mustang guy. He owns an '07 GT500 and his wife drives a 2010 GT convertible. He said he would be happy to provide an equivalent dollar amount of labor on the Boss. So I'll let him install the shifter, springs and clutch line. I figure my credit should cover about 1/3 of the labor cost. Hope to have it done before VIR Labor Day weekend but MGW shifter may not make it here in time.

The hi volume clutch line may help (I have one) but the Ford Dev team said says it's not needed. Also, they state that 'bleeding the clucth line' manually with a vacuum is pointless since the line self bleeds when you pump it. I'm just reporting what I've been told so don't kill the messenger ;D Since the brakes and clutch share the same reservior maybe there's a connection somehow if your brakes were getting soft (?). Remember what Ford told us about 'quick bleeding' brakes (Invoke ABS 2 or 3 times at 60 MPH or so). That definitly makes a difference in the feel of the pedal when the brakes start to get soft (however does not negate the need for a real brake bleed when you need it) so maybe it will make a diff for the clutch master cylinder also ?
 
Pumping does work if you pump it enough, at least on other cars, but it doesn't help during a session. The line may help during a session in theory. But I have first hand experience of 100 pumps not firming it up while 10 min with the vacuum does. Service manual says to vacuum too.

The ABS thing is BS imo, because the fluid in the ABS circuit (unless you have the dealer do it using the trigger to open the circuits) will have old fluid in it. So yeah you are swapping a little fluid, but it is not fresh fluid and it has already heated up quite a bit from being in the caliper (it is inside the caliper right? I never really looked into it). Also if your fluid is toast, and you hit the ABS, it will suck the burned fluid into the ABS circuit so next time you hit the ABS it will suck old, burned fluid into the system (fluid that has boiled before, which is when it gets spongy, has a lower boiling point) that is already heated up. And usually you need the factory test tool to open the ABS circuit while flushing to clear out the ABS. I don't know for this car specifically, but it is probably the same. You can flush, then engage ABS, then bleed, then ABS then bleed and you will have most of the old junk out but it is tedious and time consuming and I doubt many people actually do it that way.
 

PeteInCT

#LS-378 - So many Porsche's, so little time....
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The ABS thing is not BS, the recommendation came directly from a member of the Boss development team. That said, it's not meant to replace burnt fluid or a needed brake bleed, it is meant to be an interin measure if your brakes are getting a little soft and you are in betwene runs. I did it on my LS as well as on Roketman's LS when we were are Watkins Glen this year. And it works.
 
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Make sure you flush your brake fluid. The SECOND time I flushed mine, I made sure to pump the pedal a bunch and was surprised at how dirty the fluid looked in the reservoir. I use a Mighty Vac to remove the fluid from the reservoir, then fill half way with fresh, pump the pedal a bunch, repeat until you feel it's clean enough. It might help you.
 
I'll believe you then Pete, as you have personal experience with it. How big off an improvement is it? Also, does anyone know of a way to trigger the ABS to open while flushing?
 

PeteInCT

#LS-378 - So many Porsche's, so little time....
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Good question on opening the ABS while flushing, that may be another Q for the Ford team guys.

As for invoking the ABS, all I can say is the pedal felt a little too soft for my personal taste when I finished one run, Roketman felt the same. We both still had brakes but it wasn't where we needed it, especially on that track which is very fast. We spoke to Ford (don't ask how that happens, but it does) and they suggested the ABS invocation. I took my LS and Ron's out to the road and hit the ABS hard 3 times on each car (mine a '12, his a '13). When I was done the pedal was back to full firmness. Since the pedal wasn't that soft to begin with my assumption is that this technique has limited use, but if you need a quick fix until you have time to bleed the brakes fully it's a viable short solution. Unless, of course, you are close to cording your tires ;D
 

PeteInCT

#LS-378 - So many Porsche's, so little time....
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Next track event I'm going to hire this guy to pump my clutch pedal. He's good at heel/toe also...

sab-bozo.jpg
 
So it is getting spungy but isn't completely soaked. Makes more sense then, I thought you meant if they were completely gone.
 

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