I have a C5 1999 and while driving home from work, the clutch pedal every time when shifting it moved closer to the floor. After not being able to shift jam the shifter in 3rd Gear, started to drive. Then I decided to place my foot under the clutch pedal pulled up and everything was normal. After reviewing videos , I am really confused on how the braking master works with the clutch slave master cylinder and if everything ties into the shifter. I don't drive the car hard, I don't drag with the vehicle . This happened at low RPM, I don't bring the car unto 5500RPM even when I get on it. One of the things I was nervous about is if this syptom will ruin the clutch.

If anyone has these symptoms and could help me out and save me some time. The first thing I was going to replace was the Master clutch slave cylinder.

Anything would be much appreciated.

Thanks Troubleshooter

 

Did you check the clutch master for fluid level? Pull the top off, don’t just look through the side - there is a black rubber bladder that can fool you.
The clutch and brake masters are independent, though I have not done a deep dive on the pedal hangers. You can try a new master for $100 and a couple of hours, but don’t be surprised when it’s the slave.

 

Here is a photo of a clutch master disassembled. (note there is not a repair kit for these, so this is a donor master) Notice all the crud on the spool and the spring. At the end of the spring is a small cap that serves two purposes, it provides a base for the internal spring, and has a hole that acts as a flow control orifice in in case your foot slips off the clutch. This end gets filled with clutch dust that is sucked past the slave cylinder seal. This dust becomes a gooey sludge and eventually prevents fluid movement into the slave. Then, one of the spool seals ruptures or cracks and you can't develop pressure in the master to move the slave: This one blew by the seals on the spool and leaked inside the car on the firewall. (BTW, the linkage fork is not OEM)


Below is the end piece for the spring with the hole in the end. Sometimes you can save the master by removing it, driving out the little spring pin that holds the high pressure line in the cylinder body and cleaning the master with a pipe cleaner. We did this many years ago before someone thought up the idea of a remote bleeder.
Once your clutch gets sticky, all the rangering in the world won't clear up the problem. A new master/slave and a remote bleed line is the cure.

 

That makes sense, I checked all the levels and everything is full. I will purchase the OEM slave and remote bleeder.

Thank you

 

The lack of an accessible bleed is reprehensibly poor engineering. Shame on GM for doing this to so many people for so many generations of Corvette now.

 

not a small job, nor easy. you will need some way to get the car up in the air high enough to lower and move the drivetrain, separating the torque tube from the bell housing

 

Could someone define the reason for installing a tick master slave and not the same stock one you take out. Would you use the tick for adjusting the clutch pedal for racing? Not sure what to install? I was looking at LUK or Dorman. What are your thoughts?

Troubleshooter

 

The OEM master matches the fluid volume needed to produce the exact travel to disengage the clutch when the clutch pedal is at the rug. A "Tick Master" (actually a Tilton-brand master configured by TICK) has a feature that allows you to adjust this volume. Sounds good, but if you do not adjust it correctly, then you will over-travel the clutch pressure plate and your pedal pressure will go way up. OK if that is what you like, but for daily driving, you may not enjoy a heavy pedal.

Unless you are putting in an aftermarket clutch, then It will be easier with the OEM master cyl.

Dorman is cheaper, but personally, I buy genuine OEM. If an OEM fails, you have some recourse with GM over a bad part. Dorman will be chinese. Also, unless Dorman has changed their offering, their master comes without the quick-disconnect fitting that matches the OEM slave. Often, this fitting is corroded inside and won't come apart. Genuine OEM includes this fitting.

LUK clutches are the OEM brand GM put in the Corvette in the first place, Unless you are planning substantial HP mods, a direct replacement is fine. You really don't need an LS7 clutch in a C5. The exact OEM replacement clutch will take 400 RWHP no problem, except probably for drag racing use. Adding HP to a C5 is fun, and very do-able. At $100per HP you can do the math on what it costs, so that can help you decide if you want more clutch now. Sadly, most street-driven clutches aren't worn too badly. The usual problem is hot-spots on the face of the flywheel and pressure plate from poor driving technique.

What ever you do be sure to replace the pilot bearing and add a remote bleeder. When replacing the pilot bearing, you need to use a puller to remove it. DO NOT use the old-timey technique of filling the hole with wet paper and driving it out with a drift. The oil galley on an LS crankshaft is drilled from the back and all that is there is a freeze plug design seal behind the pilot bearing. All you will do is push it in. The LUK clutch package usually comes with a replacement bearing. Use that bearing, don't put a bronze bushing in there, as the system is designed for the needle bearing. If you always shift to neutral at stops and let the clutch out, the system will last a long time, as then that bearing is rotating at the same speed as the torque tube input shaft. If you have a habit of holding the clutch in at stops, you will be hard on both the pilot bearing and the throwout bearing (BTW a new throwout bearing comes with a new slave).

 

I will call Chevy today and price out an exact OEM master slave cylinder.

One more quick question, when this happens to the pedal, does the clutch get damaged? Should I just replace the master slave cylinder or do you do both?

Troubleshooter

 

not seen any damage from tick masters, just annoyingly hard pedal action.

on a c5 with no history, I would expect the hydraulic disconnect coupling will not come apart correctly. The last 2 c5 clutches we did, the nylon finger release in the coupling broke and we had to cut the line. There is a coupler half on the slave flex line and the other half is on the master line. The coupling is bonded to the flex lines, so you can’t just replace the coupling. So if that happens you need both.

short answer, it is a big enough job you don’t want to do it over, so new slave. AND you don’t find out if the repair is complete until it is all back together.

You can save on Amazon, but beware, there are some of the bigA sub suppliers selling fraud parts and in fraud oem packaging. They are getting very clever and devious. Gene Cully at Cultrag is a good source, and a ton cheaper that local chevy. He is a supporting vendor here.

 

thank you, for your help

 

if you are paying the labor to do this slave replacement, dropping the drive line is expensive. you might want to make a comprehensive list of things your old car might need in the next 40,000 miles or so that would require a drive line drop, because of the labor cost, and because the miles go quickly for most folks. I would consider the clutch and torque tube, depending on the miles , and some non stock insulation requires a straight shot to install. The exhaust sensors will never be easier to get to, but then you are adding potential complications , assembling with an untested, although new, part.

Katech is the only design I know of with a bleed valve that properly matches the tapered threading from the factory, , and not a crush washer to prevent leaks. I wish I had one.

From advice gathered here, I went with a C6 master, a direct bolt in fit, but was said to have the advantage of a slightly more moisture resistant cap. Physically it is a little bigger in the fluid reservoir , but no fitment problems, everything else works the same.