Some say the mity vac can actually reverse the seals in your master/slave cylinder, what do you think given that you dont use too much vaccum? Post up if you think its a good idea or not.

 

i think it's a good idea. i used it when i did my clutch, and i helped a friend do an LS7 clutch on a car in his shop...we couldn't get the damn thing to bleed any other way. it was weird, we tried bench bleeding, gravity bleeding, crack bleeding. weird as hell that nothing would get pressure...then i went home and grabbed my mity-vac, and it worked like a charm. there's a good write-up on here how to do it properly

 

Bleeding the clutch using the bleeder valve always works if you know the process and do it correctly. The Mity Vac can permanently damage your master cylinder, even if you don't pump it up too much.

 

Does anyone know what type of gaskets are in the master cylinder? If its o-rings then they would be inpossible to "reverse".

 

Heres that write up philip. The Buschman's clutch bleed. http://mywebpages.comcast.net/buschm...utchbleed.html

 

 

Honestly I just do it the conventional way by cracking the bleeder screw, I don't see why everyone is buying tools to make it a little easier on them, i'd rather not spend the $$$ if you can do it this way perfectly fine. Unless you don't have a 2nd person or you are handicapped or something then maybe I can see using the mity vac. It only took me and a friend like 30 minutes to completely replace all of my clutch fluid. Just drive on rhino ramps, crawl under, push pedal to floor and hold, crack screw, tighten screw, pump it up and hold to floor, crack screw, etc and add fill master as needed, hell we had 3 people so none of us had to move from our spots.

 

If you think about it, you are not "bleeding" the system using a mity vac, all you are doing is putting pressure on the system and sucking all the air out of it. There is still that old nasty burnt fluid in there that needs to be replaced. By bleeding the normal way, not only do you rid the system of air, but you also replace all the old burnt fluid.

 

Not being a dick or anything, but has anyone ever actually had a confirmed master cylinder failure due to the Mity Vac method? I see alot of people saying it can happen but haven't seen anyone say it did happen. (Then again I may not have searched hard enough either, lol)

 

Use it

 

Mity Vac worked like a champ!

 

It has worked fine for me, I've done it on four cars with nothing but a positive outcome every time.

 

i also used a mity vac on my car worked fantastic

 

I've used it many times on my stock clutch with no issues and it works well. Since changing the clutch out for the LS7 setup and a new slave, it's almost useless. As soon as I put a vacuum on the system, the clutch pedal goes soft and 3/4 of the pedal travel is slack. Remove the vacuum and pump the pedal a few times it goes back firm. Weird.

 

I would love for someone To Explain exactly how / what seals can be reversed by using this Mighty Vac? I see lots of guys talking about it BUT does anyone actulay understnd what they are talking about? What seal can be damaged and how? I would love so see a real explination on this. Thanks, Aarkangel77

 

Well, I may have messed up the master with the mityvac... The clutch had just a little bit of play, so I figured I would try the mityvac again. Now in the morning it has at least 3 inches of play in it, and will only disengage the clutch after a while of driving and letting it pump up. Im going to try the old way of bleeding it and see if the pressure comes back, if not then my master is gettin air in somewhere.

 

The only seal I can think of that people are talking about would be the piston seal in the master cylinder if it's a cup-type seal ring, but still, 10"Hg reversing that seal? Unless there's some rediculously huge amount of clearance between the piston and inside bore of the master cylinder and/or some rediculously thin seal it doesn't seem feasible to me.

 

I 'gravity' flush the system and then mity vac it - good results. Actually, I think GM released a service memo (whatever it's called) stating to use the mityvac (or equivalent) in bleeding the system.

 

I just install my LS7 clutch kit in the driveway & it needed to be bled. We were gonna do it with the bleeder valve but couldn't get to it. I used a mighty vac & it took like 15 minutes.

 

The sky is falling!