Hey everyone, looking for help diagnosing a clutch issue on my C5 (base model, 85,000 miles, stock power).

Over the winter, I noticed a sudden change in clutch behavior. The clutch began engaging abruptly at the top of the pedal travel. The engagement window is basically non-existent — the clutch grabs quickly and harshly right as the pedal nears the top, making smooth engagement difficult and sometimes causing a shudder.

Around the same time, shifts became slightly tougher. There’s more resistance going into gear, and I’ve noticed a faint clunk and some roll when engaging first, like slack is being taken up late.

Despite this, the clutch holds strong under load. I do occasional street driving and autocross, but I don’t abuse the clutch. Starts are usually rolling—not dumped from high RPM. There’s no slip, even under WOT in 4th at 20 mph. Given that and the mileage, I don’t think the clutch is worn.

I suspected a hydraulic issue and replaced the master with a Tick Performance unit. I’m using ATE Typ 200 brake fluid for its high boiling point. Bleeding was done with the master installed and connected to the pedal. I had someone pump the clutch while I held open the GM quick-connect at the end of the master line (before connecting it to the slave), letting fluid and air purge. That seemed to handle the master side, but the issue remains.

The Tick pedal feels fine overall. I adjusted it at the rod per their instructions, though it was tough to dial in—likely due to the state of the system. The clutch pedal sits about 1.5 to 2 inches closer to the firewall than the brake pedal.

The car isn’t on its original clutch. At 54,000 miles, a prior owner had a full clutch job done at a local transmission shop. The receipt lists a GM clutch, pressure plate, and flywheel, along with a new slave, throwout bearing, and pilot bearing. No remote bleeder was installed. I have one on the shelf, but I’d prefer not to drop the drivetrain unless I have to.

Here’s where I’m at:

• Could this still be a hydraulic issue—air trapped in the slave limiting travel?
• Could this be a mechanical issue, like weak or worn pressure plate fingers, even though the disc grabs fine?
• Is it possible the clutch is still holding, but these are early signs of failure?

My next thought is to bleed the system completely, including the slave. I believe you can reach the bleeder by removing the H-pipe and tunnel plate, though access is tight. Has anyone done this? Do you just pump and crack the bleeder like normal, or is a pressure bleeder better in this case?

Also, is there any way to install a remote bleeder with the drivetrain still in the car? I doubt it, but figured I’d ask.

At this point, I'm debating whether to keep troubleshooting or prep for a full tear-down: clutch, slave, torque tube refresh, and everything that comes with it.

Thanks in advance for any insight.

 

Wasted ur time. Your syetem dos not need any after market bulshit you need to change your clutch and all necessary components. its toast.

 

I get what you’re saying. I also agree the master swap didn’t solve anything. What I’m trying to nail down is why the clutch system would need replacement in this case. Usually when someone says “it needs a clutch,” they mean the disc is worn and it’s slipping, but mine isn’t slipping at all. The factory replacement clutch only has ~31k miles on it, stock power, and it holds strong even under load.

If the clutch assembly itself is the problem, I’m wondering which part is failing: worn pressure plate fingers, release mechanism issues, something along those lines. I’m still trying to figure out if this is a hydraulic problem (like air in the slave) or a mechanical problem somewhere in the clutch system that isn’t the disc itself.

 

as a disc wears the engagement point will be higher !! (when installing new clutch make sure to shim slave cyl if needed )

 

Moved to C5 Tech.

 

Well, sure, but over this past winter the engagement window shrank and the bite point moved to the very top of the pedal travel. Given the mileage and usage, I wouldn’t expect the disc to be significantly worn, and the change happened suddenly after the car sat for a few months. These are self-adjusting clutches, so they normally maintain a consistent pedal feel and engagement point as the disc wears.

I’m open to the possibility that the clutch assembly is the issue, but I want to understand the likely failure mode before committing to what is one of the most labor-intensive clutch jobs to do. I’m still hoping this turns out to be a hydraulic problem that can be resolved with a proper slave bleed, which is something I have yet to perform.

 

So am I reading this correctly that you replaced the clutch master cylinder, and did not bleed the system at the slave?

 

Yes, that's correct. Tick's instructions state that if you *don't* have a remote bleeder to just bleed just the master at the quick-connect line before connecting. Obviously this is less than ideal and why my next step will be to try to bleed from the slave.

However, it is worth noting that the problem behavior existed with the old master and the new master so I don't think the lack of bleeding at the slave caused the issue. But at the end of the day air/moisture could still be trapped in the slave.

 

If there was a hydraulic leak or air in the system, the clutch would engage pedal down near the floor (and late to disengage too)...eventually it'll start dragging and make shifting very difficult. Doesn't seem like a hydraulic issue.

ATE Typ 200 is compatible to DOT 3&4, so you're ok there.

The high engagement could point to a worn disk (unlikely...as you describe), worn throwout bearing, damaged pressure plate fingers or master cylinder linkage out of adjustment.

You mention the pedal sit lower to floor than brake pedal. Did you adjust the rod the wrong way? If you shortened the linkage it would cause a lot of the problems you're seeing. Maybe you adjusted it with the linkage not fully engaged in the MC piston, like the rod sitting on the side of a pocket instead of bedded in the middle? That could account for the sudden change in adjustment.

Wish I had more, but maybe will help you narrow things down a bit.

 

Well you set yourself up for nothing but questions here. No sense in anyone speculating on anything until you bleed the system. Put a remote bleeder in while your down there.

 

There are many threads on this forum of people that install this master and only bench bleed it like the instructions state without problem. But it doesn't mean it's proper and you make a very fair point.

Is it possible to install a remote bleeder with the drivetrain in the car? I asked this in my original post but no one has chimed in on it. I actually have one on the shelf.

I've only found one set of instructions (a YT video) of someone accessing the bleed screw on the slave. I haven't had any luck searching the forums to see if anyone's removed it and added the remote bleeder. I thought I read once that someone said it's risky or challenging because of how recessed the bleeder threads are.

 

Yup....forgot you have the drivetrain in the car. I'm sure it can be done, but you would have to have a special tool to do it given the access. Oh well, you just use the factory slave bleeder.

 

I appreciate the insight. I did not know that air in the system typically has the opposite effect, causing the clutch to engage closer to the floor. That is good to know.

The linkage is definitely not adjusted perfectly, but I do not think it is the root cause. I found the Tick instructions a little vague. In my car, with the clutch system as it is now, shortening the rod (bringing the pedal closer to the firewall) caused only a very slight creep. Per the instructions, you then lengthen the rod until the creep goes away and it shifts well. When I did that, the pedal ended up with about half the travel of the factory setup. I assumed this was because there is something wrong with my car and not something that is expected. They also warn that lengthening the rod too much can overextend the pressure plate and cause damage, so I erred on the side of caution and did not go too far.

I think I do need to lengthen it more, as the clutch pedal currently sits about 1.5 to 2 inches lower than the brake pedal. Even when I had it adjusted a little longer than it is now, I did not notice any real change in the bite point or engagement window. Only the overall stroke length of the pedal changed.