Just completed your replacement of the clutch master and slave cylinder? Looking for instructions on how to replace your master and slave cylinder on your Corvette? Check out these instructions. Clutch pedal still falling to floor or not giving any resistance after installing new parts? You probably still have air in your system somewhere.
When I replaced my master and slave I was able to drive the car fine but the clutch would periodically just go to the floor and I would have to pump it to get it to engage again to shift gears. This was a sure sign that there was still air in there. Below are some ways to get the air out. It can really depend on where the air is for the best method to use.
Just a couple of things to consider
When I replaced my master and slave, I was able to drive the car fine but the clutch would periodically just go to the floor and I would have to pump it to get it to engage again to shift gears. This was a sure sign that there was still air in there. Below are some ways to get the air out. It can really depend on where the air is for the best method to use.
Not matter what I tried I could not get the air out of my line. It was driving me nuts. A guy I ran into worked for a transmission shop and I told him my issue. He said it sounded like a leak in my clutch master. I told him I had put in a new one so that shouldn’t be the problem. It definitely was.
Moral here, new parts can still be bad. He recommended the Luk brand. Clutch worked perfectly after that.
Method from the Shop Manual
The shop manual is an invaluable tool to work on your Corvette. Want more info? Check out my review of the shop manual here.
You really need help with this process to have someone press the clutch pedal while you bleed the system you. Anyone that can press it down helps.
- Fill the master cylinder reservoir with new brake fluid, use either Dot 3 or Dot 4. Never use old or previously used fluid. I could have moisture or be contaminated and cause pressure issues
- Raise the vehicle to get to the slave. You can do this procedure without raising the vehicle but getting your Corvette off the ground sure makes it easier.
- Remove the 2 slave cylinder attaching bolts.
- Hold the slave cylinder at approximately 45 degrees with the bleeder valve at the highest point and fully press the clutch peddle to the floor. Now open the bleeder on the slave.
- Close the bleeder valve and release the clutch pedal.
- Repeat these steps until the air is all out. You should check the master reservoir periodically to make sure there is plenty of fluid. If it gets low you’ll just be pulling in more air and have to start over.
This should take care of your clutch line air issues, if not, here are a couple other things to try.
Sucking air out from the master cylinder
This was actually the final process I did to get the last little of air out of my line.
I took a brake bleeder I had and put a small tip on the end of the hose. I put the tip down into the master and pumped to get the last bit if air out. Once I started pumping, air bubbles came out into the hose line. I did this until I got no more air coming out.
I’ve seen where people have tried this sucking the air out of the master just using a hose and their mouth. I guess that could work, I don’t recommend it, you could get some brake fluid in your mount, nasty.
Run a hose up from the slave cylinder to the master
Run a hose up from the slave cylinder to the master. This one I did try and it seemed to work. Put a hose from your slave and get a hose long enough to reach your master. Open the relief valve on your slave, enough to open it up but not too much as to let in more air. Also, make sure the hose is fitted tight on the bleeder valve. The brake fluid can be very slick and could prevent getting a good connection with the hose. The hose should fit snugly on the bleeder or else this process won’t work. If possible it helps to have the front of your Corvette up higher than the back to help the bleeder valve to be slightly up at an angle.
With the master full of brake fluid, pump the clutch pedal and fluid should start going into the hose line up to the master. I had to hold the hose to the slave bleeder valve so this was another method that works better with someone to help pump the clutch while you hold the line or check the master fluid.
Continue pumping the clutch pedal until air stops coming out of the line up to the master. You may have to add brake fluid along the way. Don’t let the fluid get to low in the master or you’ll suck in more air.
Be careful to close the slave bleeder valve before your take off the hose. Conceivably air shouldn’t get in the slave but better safe than sorry.
Air should be all out of the line now.
A couple other possible methods
Remove the master cap. Pump the clutch 10 times and then hold it down for 5 minutes, then let off the clutch quickly and let the pedal pop up. I saw this mentioned a couple of times and people have said it works. It will supposedly cause the air to pop up to the safice and get out of the system. I did not use it but its something to try if your not getting the results you want.
It will self bleed on its own. Not sure about this one either but it is something to try if all else fails. Drive your car for a few days or weeks to see if they problem goes away.
If you are having a hard time getting the air out of your clutch line, I hope this post helped out. Getting the system up and working correctly is difficult on the C4 Corvette. You may need to try a couple of these methods before you find success.
Got a better method or a comment on the processes above? Leave me a comment or question below.