I recently had to replace the torque tube and also had a new clutch kit put in while it was dropped. I've been driving it for a month or so with no problems and then yesterday, I noticed slight grinding sound when I push the clutch in while the car is moving. It feels like the throwout bearing is trying to engage while the clutch is pushed all the way down. A couple of years ago, I had the master and slave cylinders replaced, due to the problem with the clutch pedal staying on the floor. I just checked the clutch hydraulic reservoir and noticed the brake fluid was black, so I cleaned it out and replaced with new fluid. Could this be causing the problem or has my master or slave cylinder already given out?

Thanks,

Sam

 

Why not take it back to the shop that performed the work?

The clutch fluid being dirty would not cause the ga grinding noise while clutch is press in.

Yes, it would have been wise to install a new slave (Around $140.) while doing the clutch.

Which brand clutch did you have installed?

 

Being that your fluid is black is not an indication that your system has failed. You note that you had replaced both components (Master / Slave). I would bleed the system and see if that corrects your problem. In addition, I would install a Remote Bleeder in the future. It saves lots of time and pain.
Why did you replace the TT?

 

The input shaft splines were reamed out and GM no longer makes the part, so my only fix, short of someone fabricating a new shaft, was to buy a used TT assembly.

Seems to me that if the clutch needed bleeding, it would have had this problem a month ago after the new clutch kit was installed.

Sam

 

Hi Sam,
Not all the time. I had a small leak in the system. Doing the turkey baster approach and pumping the clutch will help in small steps. do a search in this forum for the Bleed procedure. This is the process to Bleed the Clutch. It's not very easy and I would really think about a remote bleeder if your having some issues. Since you pull the TT, you had to disconnect the Slave from the system, check all the connection. I copied this from another post on the forum.

HOW TO bleed the clutch
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My C5 recently was exhibiting hydraulic clutch problems. It was not releasing all the way causing hard shifting and grinding gears! I checked the fluid in the master cylinder and it was at the right level but it was dirty! It was dark gray and pieces of something were floating in it. After posting a question to the CorvetteForum, several other C5 owners were exhibiting the same problems. Is the seal on the cap deteriorating? Is heat causing this? Who knows? This problem seems to happen in C5's that are 4 years old or older and the symptoms start to appear when cold weather comes around.
Well, after changing the fluid in the reservoir several times using a turkey baster, I got the clutch to operate sporadically good, but it was still having problems. After consulting the Service Manual, I decided to bleed the clutch, which resulted in a 100% improvement.
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First, clean all the dirt and debris, if any, from the clutch master cylinder cap to ensure that no foreign substances will enter the hydraulic system.

Remove the clutch master cylinder reservoir cap with diaphragm. Fill the reservoir with clutch hydraulic fluid (DOT 3 brake fluid or GM P/N 12345347).

Raise and support the C5.

Remove the intermediate exhaust pipe. To do this, you must first disconnect the O2 sensor cables. GM recommends that you disconnect the batter before performing any electrical connections/disconnections. I left the battery hooked up and I was fine. The connectors are located above the exhaust pipes just to the rear of where they connect to the exhaust manifolds. Remove the blue retaining pin. Disconnect the wiring harness and remove the retaining clips.

Now, remove the 3 nuts which hold the exhaust pipe flange to the exhaust manifold. There are 3 nuts per exhaust pipe that need to be removed with a 15mm socket. They are torqued to 20 Nm or 15 lb ft. I suggest leaving one nut on each pipe, loosely, so that you can disconnect the rest of the exhaust system first. Once all the other bolts have been removed, and the rear of the exhaust lays on the floor, you can easily undo the 2 loose nuts and lower the rest of the exhaust.
Then remove the exhaust bolts at the other end of the exhaust pipes. There are 2 bolts per exhaust pipe that need to be removed with a 15mm socket. They are torqued to 50 Nm or 37 lb ft. My exhaust gaskets were in great shape so I'll reuse them during reassembly.

Then, locate the forward exhaust hanger, just behind the clutch bellhousing. There are 2 15mm bolts that need to be removed. They are torqued to 50 Nm or 37 lb ft.
Next, remove the 2 rear exhaust hanger bolts. These require a 13mm socket. They are also torqued to 50 Nm or 37 lb ft.
Undo the 2 loose nuts from the front of the exhaust assembly and lay the exhaust on the floor.
Slide the exhaust assembly out from under the C5 and put it out of the way.
Next, locate the 36 bolts that hold the Driveline Tunnel Closeout Panel in place. This is just above the exhaust assembly you just removed. These bolts require a 5/16" socket. They are torqued to 10 Nm or 89 lb in.
Remove all but the rearmost and forward most bolts. Then, remove the rear, and support with a leg or a 2x4 while removing the front. This panel is not heavy but it is awkward.
Place the panel aside.

This exposes the torque tube.

Face the front of the vehicle and reach your hand up around the torque tube until you feel the bleeder bolt.
I removed the lower bellhousing / inspection plate to show you what you how the system works. You DO NOT need to remove this plate as part of the bleeding process. When you bleed the clutch, it's inevitable that you're going to get clutch fluid inside the bellhousing, but it will not come in contact with the clutch. It will run out of a little drain hole in the bottom of the inspection plate.
Put a 7/16" wrench on the bleeder bolt and have an assistant depress and hold the clutch pedal. Loosen the bleeder about 1/8 to 1/4 turn and retighten. Do not remove the bolt. Fluid will shoot inside the torque tube tunnel and run down your arm, as well as inside the bellhousing. Have your assistant release the clutch pedal only after you have tightened the bolt. I found that after I bled the system, my assistant had to pull the clutch pedal off the floor. But, it operated fine after that. GM recommends doing this 7 to 10 times until you have bled any air or bad fluid from the system.
Every 3 to 4 bleeds, add more fluid to the reservoir in order to prevent removing so much fluid that you draw air into the system.
This is the only way I know how to correct the clutch issue.

When you have completed the bleeding procedure, wipe any and all excess fluid from underneath the C5. This stuff is flammable and you don't want to catch your C5 on fire. Then, reverse these instructions to reinstall the Driveline Tunnel Closeout Panel and the Exhaust Assembly. Fill the master cylinder reservoir to the maximum fill line. Then lower your C5, clean up and test the results.

If you have to do all this work, I would get the Remote Bleeder....It makes life at little better.

 

I agree that the fluid being black is not allowing the clutch hydraulics to properly work and causing it to not fully disengage. It sounds like you need to use the Ranger method on a continual basis to prevent this. Now the reason it became black so quickly is usually from excessive heat from being driven hard or it is slipping, which I would think is happening since it's a new clutch. Could have been a possibility during break-in though.

 

Hornet, after reading that I'm really glad I had the Tick bleeder installed when I had my trans and clutch installed.

 

I guess I will continue with the Ranger method and see if that alleviates the problem.

Thanks to all for the info.

Sam

 

I performed the Ranger method this weekend and it was behaving better, but it still grinds occasionally. Could the master cylinder be bad?

Sam

 

You still have not mentioned what name brand clutch/pp,etc that you had installed?

 

I did not install them, so I do not know the brands. They are stock equivalent.

 

Only reason for asking is there has been previously posts in regards to using a certain aftermarket clutch & using ARP bolts, causing a grinding with the combo.

 

I don't think that is my problem, since it worked fine for the last month or so after the new clutch was installed. I'm starting to think the master cylinder is going bad. Is that unusual for one that is only 2 years old? I had replaced the clutch fluid in the reservoir 2 years ago when the pedal was on the floor. Back then, the mechanic first thought it was the master cylinder and replaced it, but it still had problems. He then replaced the slave cylinder and that fixed it. I did not replace the clutch/brake fluid until a few days ago, and it was pretty black. Could the dirty fluid have damaged the master or the slave cylinder?

Sam

 

Does it matter that I used Prestone 3 DOT?

 

Most use DOT 4 as it has higher boiling point I believe.

 

No, the fluid you are using would be fine.
I personally like Prestone Syn Dot 4.

I think the problem that you having, has to do with the slave/throwout
bearing.

I'd try bleeding the clutch(several times) first. That process will involve 2 people.

You will have regret not changing out the slave & installing a speed bleeder while it was down for repairs.
Good luck.

 

We had 9" of snow here a couple of weeks ago and the car sat outside and was not driven for a week. Could that of caused the problem? The clutch was working fine before that.

 

Should the guys that put in my clutch kit have also bled the clutch? I'm pretty sure they did not, since the fluid was black.

 

Yes, have them bleed the clutch.

They should have done it when they did the clutch,plus they should have recommended installling a speed bleeder & new slave while they had every thing exposed.
It will be a nasty job.
They will need to pull the exhaust,tunnel plate to get up in there to
do the bleed.