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Clutch Bleeding Question

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Old 02-03-2009, 08:12 PM
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Default Clutch Bleeding Question

I have read many of the different methods of bleeding the clutch. I have opted to cut the hole through the tunnel and bleeding from inside the car.
I have spent more than 1 hour bleeding the clutch, but I still get a sticking pedal after a few red-line shifts.

My MC is original (slave and clutch were replaced 4 years ago) and I fear the seals may be gone.

My question about bleeding: After opening bleeder and clutch pedal drops to the floor and after you close the bleeder, should the pedal come back up on it's own OR do you need to literally pull up on the pedal in order to start building up pressure again? I have not seen this issue brought up in any of the threads I've found.

My pedal moves to the floor (you can feel fluid come out the bleeder), and then I close the screw. But the pedal will not budge off the floor on it's own. I know there are two springs attached to the pedal, but they aren't strong enough to pull the pedal back up on their own. I'm wondering if this may be a sign of a faulty MC. OR maybe this is just normal.

Thanks for your help.
Old 02-03-2009, 08:49 PM
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i haven't had to bleed my clutch but i do know that you close the bleeder screw before you let the pedal come back up or else you're just sucking air back into the system
Old 02-03-2009, 09:10 PM
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yeppers, close the bleeder before letting the pedal off the floor. Your MC and possibly the slave are trashed. My MC went out a year ago, same symptoms, stuck to the floor at WOT, got bad enough that it happened during normal driving and I had to pump it to just change gears. Replaced the MC and has been fine till now, pedal gets hard after a wot run, but then is mushy as soon as its pushed. I am going to replace everything, clutch included.
Old 02-03-2009, 09:56 PM
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Are you sure you havent heard of mighty vac, much easier
Old 02-03-2009, 11:41 PM
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Originally Posted by LS2 WS6
Are you sure you havent heard of mighty vac, much easier
Yeah, I used mighty vac first. It didn't fix my problem, so I decided to try the traditional method (like bleeding brakes). It went like this:
"pump it" 10 times and hold it to the floor --> open bleeder --> close bleeder --> release pedal.

My question is whether or not the clutch pedal is supposed to come back up after the last step? Mine just stays on the floor and I literally have to PULL it back to the up position and then keep forcing it down and up again several times before it begins to move fluid again.

I know I'm not introducing air into the system. I just want to know if it's normal that people need to pull the pedal up from the floor after releasing the pressure.

FYI--I also tried the other method. (build a little pressure, but keep pedal UP --> open bleeder --> push clutch down --> close bleeder). This moves much more fluid more quickly, but my clutch pedal still stays down unless I PULL IT UP.

Last edited by fixinitup; 02-04-2009 at 03:17 AM.
Old 02-04-2009, 01:08 PM
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It is supposed to come back up on its own. No effort needed.
Old 02-04-2009, 01:11 PM
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the seals are most likely shot in either your master or slave. all you are doing is moving hydraulic fluid, so if you push in you are moving the fluid one way and when you let off the return spring and line pressure should return the pedal. if it doesn't you have an issue at one of your seals.
Old 02-04-2009, 11:01 PM
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Originally Posted by RsSean
It is supposed to come back up on its own. No effort needed.
This is the answer I'm looking for. Anyone want to 2nd this post? I'm pretty sure he's correct, but I'm looking for other LS1 people with experience to confirm.

Originally Posted by quickbrick
the seals are most likely shot in either your master or slave. all you are doing is moving hydraulic fluid, so if you push in you are moving the fluid one way and when you let off the return spring and line pressure should return the pedal. if it doesn't you have an issue at one of your seals.
I think that something isn't right. I guess I'll start with the MC since it's original with almost 140K miles. Now to decide between spending $150 on GM part or get in on the $300 Tick special this month. I wish tick would reduce the price a little more instead of adding a free remote bleeder (value $50). If they made the price $250 without the remote bleeder, I wouldn't hesitate to order.
Old 02-05-2009, 03:18 AM
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Do the drill mod if you haven't already, flush the fluid, bleed with mity vac. The seals should not affect whether or not the pedal returns unless they are really shot.

Is the return spring still on the clutch pedal?
Old 02-05-2009, 03:27 AM
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Yes springs are still on the pedal. I removed the plastic panel under the dash to inspect the springs. Everything looks fine (it looks like two springs under there, attached at the very top of the pedal mechanism).

I am beginning to believe that my MC is shot since nobody says they also have to pull the pedal off the floor while bleeding the clutch.

The funny thing is that the car drives okay as long as you don't drive too agressively. But once you begin to make a couple high-rpm shifts, then the pedal sticks to the floor until i literally PULL IT UP OFF THE FLOOR. Only then can I begin to slowly pump the pressure back into it so that I can disengage the clutch for gear changes.

My point is to find out if it's normal to have to pull the clutch pedal off the floor when bleeding, or if the springs are supposed to be strong enough to pull the pedal off the floor under their own force?
Old 02-05-2009, 07:29 AM
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My car has the same hydro set up as in teh LS1 one cars. I have been threw a process to swap it over. Use the same GM part number for a slave. The same ADjustable master cylinder. Same bleeding process. But I understand that you want a second opinion. LOL
Old 02-06-2009, 02:55 AM
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Originally Posted by RsSean
My car has the same hydro set up as in teh LS1 one cars. I have been threw a process to swap it over. Use the same GM part number for a slave. The same ADjustable master cylinder. Same bleeding process. But I understand that you want a second opinion. LOL
Actually, I don't have the TICK ADJUSTABLE like you have. Mine is the original GM master, so that's why I'd like someone with the stock unit to give me a 2nd opinion. Thanks for letting me know about your experience, though. It'll be good info for when I finally do get a TICK master.

I figure I can't be the only person on here with this question. Plus, none of the posts I've read mention my particular question. Is the pedal supposed to come back up off the floor when bleeding, or is it normal to have to physically pull it up after you close the bleeder?
Old 02-06-2009, 08:15 AM
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i have plenty of experience, being as i'm an ase cert. tech and it's my full-time job. please don't be scared by my post count as it so low. i joined in 2006 and just never post. it also sounds like the fluid is boiling when your driving it hard. what grade of fluid are you using? is it a stock clutch?
Old 02-06-2009, 01:24 PM
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Originally Posted by quickbrick
i have plenty of experience, being as i'm an ase cert. tech and it's my full-time job. please don't be scared by my post count as it so low. i joined in 2006 and just never post. it also sounds like the fluid is boiling when your driving it hard. what grade of fluid are you using? is it a stock clutch?
Thanks for the help. I'm using DOT 4 fluid. It's an LS6 clutch with about 40-50K miles (3 years old). Master is original with almost 140K. Drill mod was performed when clutch was replaced.

I don't have problems during normal driving, but if I take the RPM's up to 5K+ then the clutch pedal gets mushy. If I try to take the next gear to 5K RPM, then the pedal sticks to the floor and I must reach down with my hands and pull it back up. Then it still doesn't have much pressure until I pump it up and down for a bit. It will eventually return to normal. Obviously, I have a problem with something in the hydro system. Either Master or Slave or both. But, slave was changed with clutch job 40K ago.

But my question is about the pedal during the bleeding process: specifically what happens AFTER you push the pedal down and the bleeder is closed? My issue is whether or not the clutch pedal is supposed to return to the up position on it's own power, or if it's normal for the pedal to remain stuck on the floorboard? RSSean says his comes back up on it's own, but he has a TICK adjustable master. I have the original equipment GM unit.

Sorry my posts are long, but I'm trying to be as clear as possible. I'm hoping that someone chime in with their experience with the GM stock master. It seems like the springs on the pedal SHOULD return the pedal to the top, but that's not what's happening on my car.
Old 02-07-2009, 10:40 PM
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don't expect the pedal to come back up after the first bleed round. it may take several pumping, opening, closing, then releasing to get a return. you might try pulling the master off and bench bleeding it, you'll also be able to see if you have a circulation.
Old 02-10-2009, 04:39 PM
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i won't give you any adivce unless im sure what im talking about but all i have say is get a tick master adj while you are doing all this. you wouldn't believe the difference until you try and that's with my stocker clutch. btw i blew my stock fri shes resting
Old 02-20-2009, 12:05 PM
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I am actually having the exact same problem. I put in an Adjustable Ram MC in, bench bled it... did the drill mod and am still having the clutch sticking problem. When i bleed it the clutch pedal sticks to the floor just like yours. I have to raise it up and pump it a few times until it regains pressure. I have 86k miles on the factory slave/clutch setup. I guess thats where my problem lies... hope this was of some help. I feel your pain.
Old 02-22-2009, 06:37 PM
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Originally Posted by athornt2
I am actually having the exact same problem. I put in an Adjustable Ram MC in, bench bled it... did the drill mod and am still having the clutch sticking problem. When i bleed it the clutch pedal sticks to the floor just like yours. I have to raise it up and pump it a few times until it regains pressure. I have 86k miles on the factory slave/clutch setup. I guess thats where my problem lies... hope this was of some help. I feel your pain.
Thanks for adding your experience. I'm 50/50 on getting the TICK master versus getting a cheaper factory replacement (from Kragen/Checkers/Pep Boys). My debate is because I don't want to spend $300 on a TICK only to find out that I need to buy a new slave ($150) and/or a new clutch (LS7 for $500).
I have no problem doing the work myself; but I hope I'm not chasing a ghost. I guess I shouldn't complain! It's part of working on a 10 year old car with 130K+ miles!

I really need to fix the problem because I have an NX wet kit (from my old 99 Vette, RIP) that I'd like to install on this car. The vette (non-z06) handled the 150 WET kit on street tires fine with the stock clutch. I never had any troubles with that car.

Whatever I decide, I'll post back my results once I change the Master. Hopefully it'll help others with similar problems.
Old 02-22-2009, 10:05 PM
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i got the same prob sometimes i cant get into gear
Old 02-25-2009, 12:19 AM
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ive had same problems with everything new, yes i had to pull pedal up quite a few times,when i drove it hard i lost my clutch pedal, now i did drill mod, modify the rod on the clutch master, (where you cut and thread the rod) seems to be holding so far, what a pain a clutch can be
good luck



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