How to bleed a clutch with a Mity Vac

**Hi-Po** · 10-22-2009, 01:53 PM

*This could go in the General Help Section, but figured it belonged here*

*All pictures are thumb nails, click to enlarge.*

I figured I would get this information on LS1.com. I flushed my clutch hydraulics because they were very black and giving me problems at the track. I'm making this thread because I had never bled a T56 transmission, and there can never be too much information out there. I had to search for the location of the bleeder. I could not find a picture anywhere on the Internet of where the bleeder was located. It is not easy to get to, and would definitely require two people to bleed/flush. I did not have two people, so I cut a hole in the transmission tunnel. This may turn some people off, But It will be closed back up completely very soon. It made things so easy, no regrets

**Heres the picture of the bleeder screw, I couldnt find a picture anywere on the net.**

Lets start this off with the part number to the Mity Vac. PN 25136. I purchased mine from this company and had it next day. http://www.oem-tools.com/product_inf...oducts_id=1387
Here's how I had mine setup.

You need to have the end securely in the hole of the master cylinder, and it cant come out or you'll have to do it again.

I broke down and bought that awesome tool. I made the mistake of running my master cylinder dry. I bled this system 30 times at least and the pedal was barely getting any feel to it. This Mity Vac literally had bled the system in under 30 seconds. It can also bleed brake systems. The list of things it can test is also impressive. Worth its weight in gold.

I also bought a remote bleeder from Tick Performance, not knowing the the transmission must be dropped to install it. It would work very nicely, and will be going on my car this winter if I drop my transmission for sure.

You don't want to go over 10-12 HG of vacuum or you'll run the risk of pulling seals. With the hole cut in the transmission tunnel, and this Mity ingVac, flushing the system to keep it nice and clean will be a breeze and a 30 minute job. Don't have to jack the car up is a nice plus.

Here's a quick video I made showing the process. There are no bubbles in the fluid because this is the 2nd time I did it. At the end of the video, notice I pushed on that lever to release the vacuum. That has to be done before removing the hose from the master cylinder hole.

http://s61.photobucket.com/albums/h4...t=MVI_1843.flv

**Cutlass** · 10-22-2009, 05:51 PM

NICE!!!!! This is great info. I remember I tried bleeding a CTS-V clutch at work the traditional pedal pump and open bled screw and it was a major pain and didn't really work just like you described. We did it a million times and the pedal felt like crap. Next time I'll know to do it this way.
This deserves a sticky!

Edit Added Info: If your slave is new or partially empty, the Mity Vac alone may not completely remove all the air. Why? Because the hydraulic line at the slave is lower then the bleeder screw. Air could be trapped at the top of the slave. In that case a combo of Mity Vac and conventional bleeding should be tried.

**Hi-Po** · 10-22-2009, 07:39 PM

Originally Posted by Cutlass

NICE!!!!! This is great info. I remember I tried bleeding a CTS-V clutch at work the traditional pedal pump and open bled screw and it was a major pain and didn't really work just like you described. We did it a million times and the pedal felt like crap. Next time I'll know to do it this way.
This deserves a sticky!

Yea, this Mity Vac was worth it. I bet it was less then 30 seconds of pulling a vacuum.34 bucks, but I paid for next day air so I can maybe get back to the track tomorrow if it doesn't rain.

My problem was that I ran the master cylinder dry. I really think gravity feeding for an hour or two would be a major step in the right direction before trying the traditional way.

Anyone who has their transmission out should really think about installing that Tick bleeder on their slave. You can run that up to the MC and keep bleeding without having to refill the MC during the process. Leave it in car, it shouldn't ever leak.

**TRANS-DAD** · 10-23-2009, 04:37 AM

Thanks Hi-Po!!
Can't ever have too much info on this hydrolauic prob. w/F-bodies
& the hole in tha tunnel work's well we did the same to my friends camaro........home depot sell rubber plug's in alot of sizes

**Cutlass** · 12-23-2009, 05:32 PM

Thought I'd add, if you don't have a mity vac, then you need to pump the pedal several times between cracking the bleeder open to "refill" the slave cylinder. Keep a close eye on the fluid level in the master. It empties out quickly

**Hi-Po** · 04-05-2010, 08:27 AM

Found this video while searching for something else. Might help someone out on the basics.

[ame]http://www.youtube.com/watch?v=6BaECAbapRg&feature=related[/ame]

**V8MUSCLE** · 04-09-2010, 06:33 AM

how would i get all the old hydraulic fluid out? mines black, if memory serves it is supposed to be kinda like your first morning piss, just a little clearer. im having some issues and am hoping that changing the fluid will help.

**Hi-Po** · 04-09-2010, 08:50 AM

Originally Posted by V8MUSCLE

how would i get all the old hydraulic fluid out? mines black, if memory serves it is supposed to be kinda like your first morning piss, just a little clearer. im having some issues and am hoping that changing the fluid will help.

While I'm sure the MityVac would remove all the fluid, I don't think it would be safe or as effective as opening and closing the bleeder while keeping an eye on the fluid level.

The MityVac works very well for removing air from the system. Pulling too much of a vacuum could run the risk of pulling seals. Ive never heard of an actual case of this happening, its just a general rule of thumb I guess, Take it for whatever its worth I guess.

Regardless, getting clean fluid in there is a must. In solved some major issues on my setup at the track with just a fluid change/flush. Good luck.

**Camaro69Mac** · 07-01-2010, 09:28 AM

Originally Posted by Hi-Po

While I'm sure the MityVac would remove all the fluid, I don't think it would be safe or as effective as opening and closing the bleeder while keeping an eye on the fluid level.

The MityVac works very well for removing air from the system. Pulling too much of a vacuum could run the risk of pulling seals. Ive never heard of an actual case of this happening, its just a general rule of thumb I guess, Take it for whatever its worth I guess.

Regardless, getting clean fluid in there is a must. In solved some major issues on my setup at the track with just a fluid change/flush. Good luck.

So I did the drill mod and put new fluid in clutch is better but not great at the track felt roughed up stuck to the floor again but not half as bad. So what I'm asking is if I drill a bigger than 1/8" will that change anything?? Also I have the vac its great but do you bleed it with the car running or off??? I did it off

**Cutlass** · 07-02-2010, 03:16 AM

Originally Posted by Camaro69Mac

So what I'm asking is if I drill a bigger than 1/8" will that change anything?? Also I have the vac its great but do you bleed it with the car running or off??? I did it off

Bigger is better but I'm not sure the line is big enough to accept drilling bigger.
And it wouldn't matter if the car was running or not, so just bleed with the engine off.

**Camaro69Mac** · 07-10-2010, 01:46 PM

Originally Posted by Cutlass

Bigger is better but I'm not sure the line is big enough to accept drilling bigger.
And it wouldn't matter if the car was running or not, so just bleed with the engine off.

So ever since i went to the track my clutch hasnt felt the same its always feeling different everytime i drive it. Today it was hard to push in and earlier this morning very spongy. Not sure what the hell is going on but i bled it a couple more times since with the mity vac i'm wondering if i did it too much or something? Maybe i need to let some pressure out? No clue why it isnt consistent feeling.

**Cutlass** · 07-10-2010, 03:41 PM

hmmm...not sure about that. Maybe the fluid boiled and lost some of it hydraulic properties...IDK. I'm just thinking out loud. maybe your master cylinder is failing.

**Camaro69Mac** · 07-10-2010, 03:44 PM

Originally Posted by Cutlass

hmmm...not sure about that. Maybe the fluid boiled and lost some of it hydraulic properties...IDK. I'm just thinking out loud. maybe your master cylinder is failing.

ill try changing the fluid again. its perfectly clean but its worth a shot to try it.

**wildmann_87** · 11-11-2010, 10:37 AM

Originally Posted by Camaro69Mac

So ever since i went to the track my clutch hasnt felt the same its always feeling different everytime i drive it. Today it was hard to push in and earlier this morning very spongy. Not sure what the hell is going on but i bled it a couple more times since with the mity vac i'm wondering if i did it too much or something? Maybe i need to let some pressure out? No clue why it isnt consistent feeling.

im having the same problem, let me know how it works out for you

**JwMAURER** · 01-23-2011, 05:20 PM

This may be a dumb question but I'm having a hell of a time bleeding my system as well. I've changed both master and slave cylinders and I keep getting air in the line!! While your using the mityvac, are you cracking open the bleeder on the slave? And then are you just holding 12 inhg or pumping it up, releasing and then repumping? I've gravity bled this setup 6 times. Once for an hour and a half and let 2 quarts of dot 3/4 fluid thru it and tried the pumping/bleeder method countless times! Thanks for your input

**Hi-Po** · 01-23-2011, 05:26 PM

No, keep the bleeder closed when using the Mity Vac. It should remove all the air in the system in less then a minute. Worked flawlessly for me, I will never bleed the clutch any other way.

Go pick one up, give it a try and let me know the results. Should solve your head ache.

**JwMAURER** · 01-23-2011, 06:04 PM

awesome thanks for the info, ill try it tomorrow and let you know!

**JwMAURER** · 01-26-2011, 05:13 PM

Maybe I'm assuming too much here. Is the mity vac different from any other bleeder that you can buy? I have one that looks just like it so I was using that and it was making no difference. So I switched my factory master back out with a tick performance adjustable master cylinder that was in before but I thought that's what was allowing air into the system. I sent it back and they tested it and said all is well and nothing was wrong which is why I just bit the bullet and dropped the tranny and replaced the slave. After installing the master last night I seem to have the same problem. Just not as bad. I noticed some air bubbles in the "on master" reservoir but they wouldn't float out the tube or get pushed back into the system to be bled out. I once again tried the vacuum technique assuming it works The same as The mity vac and the air bubble moved to the tube neck but no further? I'm stumped. I tried to gravity bleed it but I only get drips out the bellhousing and no steady stream. Both the master and slave are brand new now and I hose clamped both the master and reservoir ends of the fluid line yet I'm continuing with The same problem! I'm about to rip my hair out

**Cutlass** · 01-26-2011, 05:24 PM

When I used Hi-Po's method, I stuck the hose end fitting in the res hole and pumped up a little vacuum. Then I quickly yanked the hose/fitting out. The vacuum in the clutch hydraulic system draws the fluid in. I did it several times and eventually you can tell there isn't any air in the system. Hopped in the car and cautiously tried the clutch. It worked great.

**JwMAURER** · 01-26-2011, 05:26 PM

I haven't tried that method yet. You can be sure I'll be trying that tomorrow! Alls I want is a consistent non fluctuating clutch pedal. Is that too hard to ask? Haha. thanks for your input. I'm willing to try anything