Mighty Vac question... Did it tonight... But how does it work???
10-23-2006, 04:52 PM
#1
Mighty Vac question... Did it tonight... But how does it work??? Hey everyone. I tried to bleed the clutch using the mighty vac method tonight for the first time. I gotta say...the pedal feels much better...and the engagment seems smoother now.
So my question isnt about how to do it... My question is how does it work?
I was still getting big bubbles out...but I stopped the process due to the fear of running the syetem dry. My common sense says that the might vac is sucking fluid/air from that hole in the master cylinder. so as you push in the clutch with vacuum applied, and air comes out...how does that not suck fluid from the system? The little reservoir on the mighty vac fills up pretty fast...
When the bubbles come into the might vac...does that in turn suck fluid from the mighty vac??? Or does it suck it from the reservioir somehow?
My process went like this... Hooked up the mighty vac...had pop push the pedal alittle in and out. Got big gulps of bubbles. And the vacuum went away. SO I had to pump up the mighty vac again. When I had enough, I hit the release button on the vac and tried the pedal. Im pretty sure thats the jist of it.
Ive heard so many people say it works...and Im beginning to become one of them. However Im more trusting of something, and im sure im not the only one...if I know how exactly it works. Maybe Im missing something obvious but I just cant visualize exactly whats happening using this method...
Anyone care to enlighten me/us???
Justin
So my question isnt about how to do it... My question is how does it work?
I was still getting big bubbles out...but I stopped the process due to the fear of running the syetem dry. My common sense says that the might vac is sucking fluid/air from that hole in the master cylinder. so as you push in the clutch with vacuum applied, and air comes out...how does that not suck fluid from the system? The little reservoir on the mighty vac fills up pretty fast...
When the bubbles come into the might vac...does that in turn suck fluid from the mighty vac??? Or does it suck it from the reservioir somehow?
My process went like this... Hooked up the mighty vac...had pop push the pedal alittle in and out. Got big gulps of bubbles. And the vacuum went away. SO I had to pump up the mighty vac again. When I had enough, I hit the release button on the vac and tried the pedal. Im pretty sure thats the jist of it.
Ive heard so many people say it works...and Im beginning to become one of them. However Im more trusting of something, and im sure im not the only one...if I know how exactly it works. Maybe Im missing something obvious but I just cant visualize exactly whats happening using this method...
Anyone care to enlighten me/us???
Justin
10-24-2006, 06:42 AM
#3
From what I understand...20 in Hg (not psi) is alittle too much. The majority will tell you 12-15 in Hg. So as to not damage the seals in the master cylinder. There doesnt seem to be any hard proof that it does damage it...but I figured better safe than sorry...and stuck to 12.
I believe it goes like this... Make sure there is fluid in the mighty vac reservoir so that the hose goes down into it. Bring the master cylinder reservoir up to level. What I did next was suck fluid up into the hose for the mighty vac. So that no air was in the line. Not sure if this is what I was supposed to do or not...Im thinking not now... Stick the nozzle into the hole in the master cylinder reservoir. Pump it to 12 in Hg. Then have someone slowly push in the clutch pedal.
When I had someone do this...I got lots of bubbles in the tube and into the mighty vac reservoir. The vac also went away, and I had to pull more on it to continue.
After I did it..I noticed that the black fluid (yeah I gotta flush it) was in the might vac reservoir. Thats what made me worried that I was sucking too much from within the clutch hydro system. If what I was doing was correct...and i was infact releasing air in the system, I will keep doing it. My car did feel better afterwards...although it could be my imagination too. Also I have nothing to compare it too because this is the first time driving the set up.
Justin
I believe it goes like this... Make sure there is fluid in the mighty vac reservoir so that the hose goes down into it. Bring the master cylinder reservoir up to level. What I did next was suck fluid up into the hose for the mighty vac. So that no air was in the line. Not sure if this is what I was supposed to do or not...Im thinking not now... Stick the nozzle into the hole in the master cylinder reservoir. Pump it to 12 in Hg. Then have someone slowly push in the clutch pedal.
When I had someone do this...I got lots of bubbles in the tube and into the mighty vac reservoir. The vac also went away, and I had to pull more on it to continue.
After I did it..I noticed that the black fluid (yeah I gotta flush it) was in the might vac reservoir. Thats what made me worried that I was sucking too much from within the clutch hydro system. If what I was doing was correct...and i was infact releasing air in the system, I will keep doing it. My car did feel better afterwards...although it could be my imagination too. Also I have nothing to compare it too because this is the first time driving the set up.
Justin
10-24-2006, 07:53 AM
#4
You were just taking air out of the system. If you pulled any fluid it would have backfilled from the reservoir. Which is why after you bleed you need to be sure to top off the reservoir. I usually do the same thing you did about 3 or 4 times in a row but in between bleeds, I top off the reservoir, close the cap, and pump the clutch pedal a bunch. That assures I have plenty of fluid in the system and allows me to top off the reservoir again as I always check it one last time after pumping the pedal.
If you were still getting bubbles, I would recommend you continue to bleed but keep the pressure lower so you do not damage any seals. The first time I did mine I got big bubbles, especially when pumping the pedal. After that not much air came out, just some really small bubbles. So I pump the pressure and let it sit for a few minutes just to make sure. Then release the mity-vac pressure slowly so you do not put dirty fluid back into the system.
You can also use the mity-vac to suck your reservoir dry and then refill it with clean fluid. That is how I have been doing my cheater fluid change as I did not have luck with the bleeder under the car. A bleeder extension will be added this winter with my new clutch to allow for a proper bleed.
If you were still getting bubbles, I would recommend you continue to bleed but keep the pressure lower so you do not damage any seals. The first time I did mine I got big bubbles, especially when pumping the pedal. After that not much air came out, just some really small bubbles. So I pump the pressure and let it sit for a few minutes just to make sure. Then release the mity-vac pressure slowly so you do not put dirty fluid back into the system.
You can also use the mity-vac to suck your reservoir dry and then refill it with clean fluid. That is how I have been doing my cheater fluid change as I did not have luck with the bleeder under the car. A bleeder extension will be added this winter with my new clutch to allow for a proper bleed.
10-24-2006, 09:49 AM
#5
Yeah before I started to bleed it I sucked all the fluid that I could otu of it with the mighty vac. I guess what I was seeing was normal then. Maybe Ill try it again until I get no bubbles.
So when doing this...you are watching your fluid level, and without removing the mighty vac you add alittle fluid to keep it full? Im really hoping that there was in fact air in the system. Because that means the clutch feel/operation can only get better.
Justin
So when doing this...you are watching your fluid level, and without removing the mighty vac you add alittle fluid to keep it full? Im really hoping that there was in fact air in the system. Because that means the clutch feel/operation can only get better.
Justin
10-24-2006, 11:08 AM
#6
When the mity-vac tip is in the hole at the bottom of the reservoir, there is no fluid going back into the clutch hydraulics. The tip is blocking that and since you create vacuum, you know you have a tight seal. I refill the reservoir after I finished the bleed process and release the vacuum pressure. I would not suck it dry and then bleed. Make sure there is some fluid in there when you do this. I would suck it dry, refill, and then perform the bleed. That way when I cycle the pedal after the bleed, I know there is fluid in the reservoir should it need any. And as I said, I check the level again after cycling the pedal after the bleed. Just to make sure.
A few guys have stated that they had a hard time bleeding the system because they kept sucking air in and found the reservoir hose was not very well attached. I think they replaced the zip tie with a hose clamp and that fixed it. Their power bleeders are what identified that issue. Something else to keep in mind.
A few guys have stated that they had a hard time bleeding the system because they kept sucking air in and found the reservoir hose was not very well attached. I think they replaced the zip tie with a hose clamp and that fixed it. Their power bleeders are what identified that issue. Something else to keep in mind.
