1st HPDE on my new LPX Clutch - 5 laps of kicking ass then clutch pedal goes to floor and stays there

Biggus Dickus

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Well, I was totally stoked for what should have been a great day. I had been driving around with my new LPX clutch and MGW shifter which are fantastic upgrades. I couldn’t wait to get them to the track for an HPDE. so I went to auto club Speedway for the Roval track day today(fast with long straights) But it was hot too. Over 100°.

Everything was going great. My temperatures were all fine. I Wasn’t over revving the motor. usually I was shifting around 6500-6800, occasionally getting up to 7000, but not too often. On my fifth lap, I hit a straight and take off and when I go to shift, the clutch pedal goes to the floor and stays there and I can’t get into gear.

Luckily I was able to pull off to a safe area without damaging my car, I shut the motor down. Then when I restarted it I noticed that the car would immediately start moving forward. So apparently it was in gear somehow. I was able to put it in first, start it and immediately give it gas go and limp back to the pits. It actually kinda felt normal when I did this

No leaks outside the car. No leaks inside the car where the clutch pedal is . No leaks under the car. Brake reservoir was full, and actually over full. Brake fluid (stock OEM DOT4) was really HOT! It wasn’t idling weird like there was a vacuum leak at the brake booster. So I don’t think there were any leaks there.

Patrick “Paddy Prix” Helped me immensely. We thought maybe there was an air bubble trapped within the line, so we sucked and sucked and sucked on the reservoir with a pump at about neg 15 to 20 pounds, and pumped and pumped and pumped the clutch, but to no avail. No air came out. No increased resistance in clutch pressure. Clutch would stay to floor when pushed in despite our efforts and the brake fluid cooling down.

The system held negative pressure with no problem and no evidence of any leak.

Gear shifter works fine. Goes through the gears fine.

So, I know I need to take it to the shop, but I wanted to share my experience, hear some ideas, and give me some advice as to what I can do NOW and in the FUTURE so this fucking nightmare doesn’t happen again.

The worst thing was the car was just doing great, it was working really really well, despite the incredible heat. At least until it wasn't working well.

Thanks all for reading this and sharing your thoughts.

 

Zrussian13

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What slave cylinder did you use with the new clutch?
 
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Biggus Dickus

Biggus Dickus

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What slave cylinder did you use with the new clutch?
I'm pretty sure we kept the original OEM - which was probably not a good idea.

That said - is there any kind of "upgrade" for a slave cylinder?
 

Zrussian13

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Oem is the way I'd go. I see a lot more issues with the aftermarket ones but I'd definitely put a new one in if im already in there doing the clutch. Keep us posted on what the problem ends up being. I wouldn't think the lpx would fail on you that quick...
 
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Biggus Dickus

Biggus Dickus

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Oem is the way I'd go. I see a lot more issues with the aftermarket ones but I'd definitely put a new one in if im already in there doing the clutch. Keep us posted on what the problem ends up being. I wouldn't think the lpx would fail on you that quick...
Thanks - I will be shocked if the problem is with the clutch itself: It's new, I properly broke it in, and I wasn't power-shifting, and my shifts were smooth. But now I have to have the trans pulled for what hopefully will be nothing more than a 3 minute job.
 


Zrussian13

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Thanks - I will be shocked if the problem is with the clutch itself: It's new, I properly broke it in, and I wasn't power-shifting, and my shifts were smooth. But now I have to have the trans pulled for what hopefully will be nothing more than a 3 minute job.
I had to drop my tranny 3 times to get my lpx-hd right so I feel your pain there. Worse part is it was because bad install advice from mcleod. Once I got it dialed in I loved it. I've got 20k miles on mine now. It handles 8k power shifts all day no problem.
 
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Biggus Dickus

Biggus Dickus

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I had to drop my tranny 3 times to get my lpx-hd right so I feel your pain there. Worse part is it was because bad install advice from mcleod. Once I got it dialed in I loved it. I've got 20k miles on mine now. It handles 8k power shifts all day no problem.
I love the clutch - that plus the MGW shifter and it felt like a new car. The combo was great at the track - the car's going in Thursday. At least I have the money to pay for it:crackup:
 
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Biggus Dickus

Biggus Dickus

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Slave cylinder took a dump. Clutch is fine. Upgrading to Motul 600 RBF.
 

Kennysum1

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Red65

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The stock slave cylinder is known to have issues and sometimes just give out randomly. Granted, most that give out prematurely have been ragged on pretty hard, but even those that are treated properly don't seem to last much longer than the factory clutch. As inexpensive as they are, I've just considered them a wear item to be replaced along with the clutch.
 
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Biggus Dickus

Biggus Dickus

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Rip Mr. Slave. He did what he could.
I think a 105 deg track day in Fontana with asphalt temps of 135 was more than he could handle.

As I recall, right before it failed, I think I heard a faint "f-you" coming from the trans-tunnel.
 
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Biggus Dickus

Biggus Dickus

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Turns out the slave cylinder failure was caused by the pressure plate failing:
298899349_574615314393095_4103239281402482352_n.jpg
298811843_1248542222625197_4810987763864837276_n.jpg
298752861_3363128324015573_4275926825479718313_n.jpg


296041423_609000990851226_1945678135230273210_n.jpg


299113210_430946032407106_4976745968718469507_n.jpg
 

Cobra Jet

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Did you contact the selling vendor or the manufacture to get a replacement?
 
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Biggus Dickus

Biggus Dickus

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Did you contact the selling vendor or the manufacture to get a replacement?
Yes - It's at McLeod on a warranty claim - waiting to hear back
 

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