Odd inconsistent clutch pressure issue....
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Teching In
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Odd inconsistent clutch pressure issue.... I have a turbo lm7/t56 in a Lexus is300. Ls7 clutch set-up with an ls2 flywheel. The issue I'm having is odd, I have a wilwood 7/8 clutch master cyl, new slave, and when I went to bleed the clutch I had a HELL of a time getting the master to pump fluid. Finally put a vacuum pump on the remote bleeder line and slowly got it to pump fluid. Bled all the air out, and started driving it. Now sometimes the pedal will fall half way before it begins to disengage, and other times it's RIGHT at the top... And I was driving it yesterday, got on it, and the clutch slipped. When I went to push in the clutch, it was clearly pressurized internally, causing the clutch to slip. Pedal was hard. Pushed it in once, and it went back to normal, no slipping. Originally I thought was the master cylider, but now I'm not so sure. Tried bleeding it again to double check, no air in the system. No leaks. When you bleed it, after you relieve the pressure, it takes FOREVER to get a pedal again, and it seems like it doesn't matter how much you pump it, it just matters how long you let it sit. If you push the clutch in, relieve pressure, and try to pump the clutch again, there's nothing. But if you walk away for a few mins, and try again... Full pedal. Any insight is greatly appreciated!
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Is the nipple the fluid goes in from Reservoir of the Wilwood positioned so it is the highest part of the MC as it is mounted in your pedal set-up?
If not than bleeding the system with the fill nipple lower will trap air in the system while bleeding.
FWIW I also have a Wilwood MC (McLeod) and have it mounted in a custom pedal assembly for a car that was never built as a manual car.The MC mounted in my pedal assembly has the fill nipple pointing down so I had to bench bleed the MC.
I Tried Mighty Vac several times with no luck
If not than bleeding the system with the fill nipple lower will trap air in the system while bleeding.
FWIW I also have a Wilwood MC (McLeod) and have it mounted in a custom pedal assembly for a car that was never built as a manual car.The MC mounted in my pedal assembly has the fill nipple pointing down so I had to bench bleed the MC.
I Tried Mighty Vac several times with no luck
****** does make an interesting point. It might be worth doing an in-car bench bleed:
Disconnect the slave, use a screwdriver to push open the check valve while assistant pumps pedal. DO three pumps, fill the reservoir, do three more. You might get a burst of air out the first time or two and then it quits. Reconnect and bleed slave.
You could also have the seal in the master internally bypassing, which is unlikely, but sort of sounds like what you have. Especially if an in car bench bleed doesn't help.
Disconnect the slave, use a screwdriver to push open the check valve while assistant pumps pedal. DO three pumps, fill the reservoir, do three more. You might get a burst of air out the first time or two and then it quits. Reconnect and bleed slave.
You could also have the seal in the master internally bypassing, which is unlikely, but sort of sounds like what you have. Especially if an in car bench bleed doesn't help.
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Joined: Apr 2008
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I assume you have the Wilwood "compact" MC mounted in some fashion to your pedal assembly. Maybe "moving" it slightly while bleeding (bubble can hang up inside so slight tilting back/forth while bleeding may dislodge any bubble
Pic of my Wlwood for my McLeod Twin clutch. Mcleod makes the adapter for my model to mount as a 94-97 F-body would...but in my "custom" pedal assembly designed to use a F-body MC...its orientation is not with the nipple at the highest point so I had to bench bleed. I actually bleed the entire system as I can remove slave and install Reservoir, MC & slave as a sealed unit (LT1 car). Your LSx you cant as slave is part of TO bearing IIRC.
You can contact Wilwood direct for ?'s on their Tech line. I suspect they have a MC rebuild kit if that is what it turns out to be.
are you losing any hydraulic fluid?
