I installed a new ls7 clutch and could not get the clutch to disengage or get into gear. Long story short if you have air in the system you will think you need a shim but you dont. First thing first install the clutch as a direct bolt up. If you replace the slave here is a tip.

1. Bleed the system if you broke the line in any form or fashion before you try anything. It wont work if you have air in the system. Use Dot 4 fluid as a minimum cause it has a higher boiling point.

2. First bleed the air out of the slave cylinder. My step for this is open the bleeder then push clutch to the floor. dont release clutch until bleeder is closed. do this 4 to 5 times or till you get straight fluid out the bottom around 4 times fill the resivior again so you wont take on more air.

3. Now it is time to gravity bleed the system. this will take around ten miniutes. crack the bleeder about half way until you get a low drip and constantly fill the resivior as needed. do this until the drip turns to a steedy flow then close the bleeder. By now you should have a low pedal.

4. Now get the mity vac out and set it up as follows. One line without the catch can on it with a nozzle large enough to fill the line hole in the bottom of the resivoir. vacum will hold the nozzle in place on you start to apply pressure. first pull was at 5 in with a hold for 3 mins. push to clutch in slowly and out slowly. ( you may have to pull it up by hand). every min.
then move the vacum pressure to 10 in and repeat process you will see bubble moving up the line as the surface. donot let the fluid come all the way to the top of the line. I pulled my system until I reached 20 in and no bubbles came to the top. Working the pedal every now and then let the air pass through the master if any is below that point. I stopped pulling at 20 inches with no damage to the system.
5. At this point I tested the system and it worked flawless and shifted smooth as silk. no clutch sticking to the floor and I can now power shift at 6800. ( break clutch in around 200 miles in town or use heating and cooling cycles) your choice just break it in before you start grabbing power shifts. the ls7 hold great. I have 423rwhp. hope this helps

 

Thanks for that write up. Im sure it will help a bunch of people.

 

I just want to kno why does everyone go through the hassle of opening the bleeder to bleed ther're clutch hydraulics? I did an LS7 clutch swap into my SS and all I did was hook the line up to the slave cylinder and pump the clutch pedal until bubbles stopped coming out of the resevoir, by the 10th pump of the pedal I could feel the slave cylinder moving the pressure plate. I took about 20 to 30 pumps and I was golden and haven had a problem. I've had the the LS7 clutch in my car for 7k miles. GM says to bleed their clutches by pumping the pedal.

I also did a new clutch install on a 6spd SSR and the slave cylinder didn't even have a bleed on it.

 

cause i never read the tech bulletin. I will try your way when I get a chance sounds like it saves time thanks for the tip

 

Yeah I didn't have to bleed either. Just pumped the pedal 10 to 20 times and was good to go

 

Are you the guy who called us for a week or so insisting that the clutch was bad, and needed to be shimmed, etc?? The one that we kept telling it should work that you likely had bad hydraulics or air in the system??

Glad you got it worked out regardless! Enjoy