I have about 435 rwhp. I pulled the assist spring off the clutch that makes the pedal return 'up' harder. Even on a cool 50 degree night, on a punch to wot and it stuck down and wouldnt let me engage a gear.

So, I know the fluid is overheating. (right?)

I dont seem to have trouble w slipping though. So do I need bigger master cylinder to carry more fluid? Or does a stronger clutch fix this issue?

I dont want to just do both unless it makes sense-ie it all has to come apart to replace one or both. (working on a budget!!).

 

I had the exact same problem. At the end of 1/4 mile runs the clutch was sticking all the time. I went with the RPS clutch and have not had a problem since.

First try to drain your clutch fluid out and replace it. this may or may not help. You have to drain it from the top though so get as much as you can then in 3 days do it again. Repeat this process for about 2 weeks and you might get lucky to replace most of the old with the new....

If changing the fluid does not work then since you are on a budget I would look at the new LS7 clutch and flywheel which people say fit and have given some good write ups on. The total cost is around $500 for the parts and then there is labor costs on top of that. Figure 1 day of labor.

 

Also, there is a spring on the pedal pivot that's there to help you hold the pedal down at stop signs, etc. Take that off and see if it helps.

 

We all have seen clutch problems like this since 97. Here is what we have found. The problem starts with the pressure plate. The pressure plate is weak from the factory and does not have a lot of clamping pressure. So the clutch slips at high Rpm’s where you are making more HP on the shifts. When the clutch slips it will radiate more heat. Some of the heat will be transferred into the slave cylinder over heating the hydraulic fluid. When the fluid reach’s its boiling point, the fluid will go from a liquid, which can’t be compressed, to a gas, which can be compressed. So when you step on the clutch pedal and the fluid compresses, the pedal will stick to the floor. Then you have to lift up the pedal with your foot and pump it a few times to cool the over heated fluid.

The main problem in the factory hydraulics, is the fluid. It uses brake fluid. Brake fluid absorbs moister over time and moister lowers the boiling point. When we build new master cylinders for the after market clutch’s, we use synthetic brake fluid with has a boiling point of 610 degrees. The fluid still absorbs moister but it will take longer before it needs to be changed. We also modify the master to put out a higher volume of fluid, but this is for better and quicker release of the clutch when using higher-pressure plate pressures.

Some people have recommended removing the clutch pedal assist spring. All this will do is require more pressure to step on the clutch pedal and mask the problem. The fluid is still over heated and will not give you full release of the clutch. If the clutch is not fully released, the shifts may be forced, damaging the transmission. The correct fix is to replace the clutch with a stronger unit and at least replace your clutch fluid.

I hope I have been of assistance and shed some light on your problem.

 

I anticipated a response like this. I was writing my reply at the same time as you and was not directing my response at you.

 

I agree that this does help, but it does not solve the problem. I did it and although the clutch did perform better it still was not perfect. Ihappen to like the feel though and have left it off even with my new RPS clutch.

 

Before you do anything, check out my simple clutch arm mod that reduces clutch throw and engages the clutch earlier off the floorboard. It also seems to help or eliminate your problem. With your engine mods you probably won't get a free GM fix.

http://forums.corvetteforum.com/pho...500&ppuser=6747

Check out that little metal gizmo that I attached backwards to the clutch arm nubbin that engages the switch on the floorboard/firewall.
Or you can rig up your own gizmo. I had the clutch stick to the floor before I did this.

 

I believe it is a bad link or just not working, but I just installed a clutch stop because of other issues I have with the RPS clutch at the 1/4 mile track(this probably is the same concept as you mention above). Unfortunately I have not taken to the 1/4 mile to see what happens. I did have it at Watkins Glen and there were no issues.

 

Check it later, it seems to be up and down today....

 

It's a bad link.

Here's the fixed one

http://forums.corvetteforum.com/phot...00&ppuser=6747

 

here's another fix I dont know if anyone on this forum has noticed
http://www.chevyhiperformance.com/ho...021/index.html

 

If your car is a pre-02 model it needs to have the Clutch slave upgraded to the 02-current one.

you should replace the clutch as well since you will have to do 90% of the work to get the slave out.

pre-02 cars are notorious for clutch to the floor issues.

 

F@%K!! This exact thing just happened to me tonight! It's nice and cool here right now and I'm seeing 10 psi at my shift point. I wound out 2nd and 3rd and couldnt shift into 4th. It was as if there was a lot of air in the hydraulic system. I stayed in neutral and pumped the pedal and after about 3 seconds I had a solid pedal again. I have already upgraded to an 03 zo6 clutch/slave/master etc...

I'm at around 560 rwhp now and I know for a fact that the clutch slips at the upper rpm range, I just didnt realize that the slippage causes that much heat to boil the hydraulic fluid.

Oh well I guess I know what this winter's project will be. I'm off to search land to see whats available for high hp clutches.

Jer.

 

man good info guys, thanks!

So I can blame the master/slave but if I have it all apart the clutch is right there anyways.

Thanks all

 

While there is new part numbers, we have yet to find a difference.

I do recommend changing the slave any time the clutch is replaced. It is cheep insurance. The last thing you want to do is go back in because of a failure.

 

Good stuff.