Help - clutch pedal pushing back at be at high rev shifts
Discussion
Put this on Ls1tech - but nothing yet?!
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Since I have had my cars ecu / pcm tuned (now 400ish bhp - but std z06 numbers) it is exhibiting a weird clutch issue.
Spoke to the Paul at Wortec on Sunday (had a Blown Holden car he was working on, and he and owner said they had heard of the same and that it is documented somewhere on the web.
When accelerating and then changing gear at high rev’s i.e. 6k + the clutch pedal physically pushes back at you as you make the shift – really weird and disconcerting.
After a few shift like this one after the other the clutch / change is lost!
They seem to think that the cause is somehow created by a vaccum pulling in on the small bore braided pipe from the Hydraulic release bearing back to the master cylinder. On the second or third high rev change the clutch is actually still not fully disengaged because of this and the clutch wears out!
They seem to think someone has diagnosed this and says that a larger bore pipe (braided and the fitting in the Hydraulic release bearing and the Master cylinder are needed) – such that any vacuum cannot close down this size of pipe.
As you can imagine to get this pipe change out is a gearbox out (or on my car an box and engine out or cut two whole in the base of the bellhousing to get the small bore pipes off and replace with custom made larger bore ones?
I have a TKO gbox with a Hydraulic release bearing (std Z06 corvette Z06 clutch pate and cover / flywheel), but same seems to happen on Holden with T56 and Hydraulic release on their hybrid LS1/6 Blown lumps.:confused::confused::confused::confused:
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Since I have had my cars ecu / pcm tuned (now 400ish bhp - but std z06 numbers) it is exhibiting a weird clutch issue.
Spoke to the Paul at Wortec on Sunday (had a Blown Holden car he was working on, and he and owner said they had heard of the same and that it is documented somewhere on the web.
When accelerating and then changing gear at high rev’s i.e. 6k + the clutch pedal physically pushes back at you as you make the shift – really weird and disconcerting.
After a few shift like this one after the other the clutch / change is lost!
They seem to think that the cause is somehow created by a vaccum pulling in on the small bore braided pipe from the Hydraulic release bearing back to the master cylinder. On the second or third high rev change the clutch is actually still not fully disengaged because of this and the clutch wears out!
They seem to think someone has diagnosed this and says that a larger bore pipe (braided and the fitting in the Hydraulic release bearing and the Master cylinder are needed) – such that any vacuum cannot close down this size of pipe.
As you can imagine to get this pipe change out is a gearbox out (or on my car an box and engine out or cut two whole in the base of the bellhousing to get the small bore pipes off and replace with custom made larger bore ones?
I have a TKO gbox with a Hydraulic release bearing (std Z06 corvette Z06 clutch pate and cover / flywheel), but same seems to happen on Holden with T56 and Hydraulic release on their hybrid LS1/6 Blown lumps.:confused::confused::confused::confused:
Cant say ive had a problem with mine ??
Are you saying the pedal gets very stiff when shifting ? cant quite figure what you mean by the pedal pushes back, as you press ?
The only thing that applies pressure back into the slave/pedal, is the force of the actual clutch cover. I cant see any circumstances that would cause it to change ?
When your pedal is at rest, can fluid flow freely through the system if you remove the bleed nipple at the slave ?
If this was adjusted or setup wrongly, you could have a situation where you continually pump fluid into the slave, but it cannot escape. While it could result in a heavy or even solid pedal, it would also hold the clutch open causing it to slip.
Are you saying the pedal gets very stiff when shifting ? cant quite figure what you mean by the pedal pushes back, as you press ?
The only thing that applies pressure back into the slave/pedal, is the force of the actual clutch cover. I cant see any circumstances that would cause it to change ?
When your pedal is at rest, can fluid flow freely through the system if you remove the bleed nipple at the slave ?
If this was adjusted or setup wrongly, you could have a situation where you continually pump fluid into the slave, but it cannot escape. While it could result in a heavy or even solid pedal, it would also hold the clutch open causing it to slip.
Suggest you have a look through C5 Tech on corvetteforum.com, or possibly post your question there.
Don't know if this is the same in your case but I remember reading about issues people had with clutches on high power 'vettes, I seem to remember that there is some kind of restrictor in or around the clutch master cylinder that had to be drilled out. The restrictor was there to help smooth out gear changes on stock vettes but on the more potent ones it caused problems and had to be removed.
Don't know if this is the same in your case but I remember reading about issues people had with clutches on high power 'vettes, I seem to remember that there is some kind of restrictor in or around the clutch master cylinder that had to be drilled out. The restrictor was there to help smooth out gear changes on stock vettes but on the more potent ones it caused problems and had to be removed.
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