Bleeding brakes with vacuum pump
Thread Starter
Burning Brakes
Joined: May 2009
Posts: 1,232
Likes: 6
From: Tucson AZ
St. Jude Donor '12
Bleeding brakes with vacuum pump
I've read the many informative posts about brake bleeding. I still have one question:
Is it ok to 1 man bleed the brakes with a vacuum pump? I wonder if it will cause the prop'g valve to do its one-sided thing? I rebuilt all 4 calipers, repolaced the lines, and had to replace a couple of the hard lines.
EDIT: I installed O-Ringers all around. Been vacuuming for 20 mins, and its been nothing but a fart in a bubble bath so far.
Is it ok to 1 man bleed the brakes with a vacuum pump? I wonder if it will cause the prop'g valve to do its one-sided thing? I rebuilt all 4 calipers, repolaced the lines, and had to replace a couple of the hard lines.
EDIT: I installed O-Ringers all around. Been vacuuming for 20 mins, and its been nothing but a fart in a bubble bath so far.
Last edited by RobbSalzmann; Aug 13, 2009 at 03:11 PM.
Melting Slicks
Joined: Aug 2006
Posts: 3,429
Likes: 20
From: Kingston Ontario
Sorry but I have all that Robb, everything new, MC, lines, braided flex lines, calipers. That vacuum pump wouldn't do a thing except for pull all the rear pistons in and thats it. I even used a vacuum generator which is move even vacuum and it's a no go. I had my best luck with pressure right at the MC, only 15 psi shoved it through in seconds. Kind of Bubba'ed it but it worked perfect. As far as the spool in the prop. valve.... I was trying to pedal the fluid through and it locked, I released it by cracking the front caliper and pushing the pedal. That centered it. I got the front bleed before the back, thats why it locked. Once centered , vacuum or pressure never affected the prop. spool.
Oh...I did it myself the bubba way
http://forums.corvetteforum.com/c3-t...he-blakes.html
Oh...I did it myself the bubba way
http://forums.corvetteforum.com/c3-t...he-blakes.html
Burning Brakes
Joined: Apr 2007
Posts: 1,039
Likes: 62
From: Kona Hawaii
If your calipers are fitted with the LIP SEALS do not try to vacuum bleed you will suck air back into the system! It will make things even worse.I tried it and it was a disaster!It may work if you have O ring type seals someone who has done it can answer that one.I was successful using Speed Bleeders and alot of brake fluid. I also tried to bleed with the regular bleeders and it was difficult to get the wife to follow directions (what else is new).Best bet is to use a pressure bleeder.Search the forums you will get a lot of useful info.I was shocked at how much air was in the system and how much time it took to get all the air out after a leaking caliper was repaired.Alohas
Thread Starter
Burning Brakes
Joined: May 2009
Posts: 1,232
Likes: 6
From: Tucson AZ
St. Jude Donor '12
If your calipers are fitted with the LIP SEALS do not try to vacuum bleed you will suck air back into the system! It will make things even worse.I tried it and it was a disaster!It may work if you have O ring type seals someone who has done it can answer that one.I was successful using Speed Bleeders and alot of brake fluid. I also tried to bleed with the regular bleeders and it was difficult to get the wife to follow directions (what else is new).Best bet is to use a pressure bleeder.Search the forums you will get a lot of useful info.I was shocked at how much air was in the system and how much time it took to get all the air out after a leaking caliper was repaired.Alohas
Drifting
Joined: Apr 2007
Posts: 1,970
Likes: 45
From: Cameron Park CA
I have a Mityvac which I have used for years on motorcycles with great success. I tried to use it on my Corvette and found my hand cramping before I could get any fluid into the container. I stopped using the Mityvac for the Vette, BUT I do use the container and hose setup that comes with the Mityvac and have my wife push the pedal for me.
I use the container and tubes because when the container is full, it's time to refill the master cylinder, so it's an easy way to keep from draining the master by mistake. The other reason I like the container setup is because the tubes are connected to the top so they aren't slipping out and spewing brake fluid on the floor and elsewhere. Also, the tube inside the container is kept under the brake fluid so air isn't drawn into the caliper. Along with Speed Bleeders, this system has worked flawlessly for me.
I use the container and tubes because when the container is full, it's time to refill the master cylinder, so it's an easy way to keep from draining the master by mistake. The other reason I like the container setup is because the tubes are connected to the top so they aren't slipping out and spewing brake fluid on the floor and elsewhere. Also, the tube inside the container is kept under the brake fluid so air isn't drawn into the caliper. Along with Speed Bleeders, this system has worked flawlessly for me.
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Melting Slicks
Joined: May 2003
Posts: 2,074
Likes: 280
From: Dyersburg TN
Motive
I have done them pump and hold as well as vacuum. This gadget made my life so much better.
http://www.jegs.com/i/Motive+Products/715/0105/10002/-1
http://www.jegs.com/i/Motive+Products/715/0105/10002/-1
Race Director
Joined: May 2006
Posts: 16,528
Likes: 53
From: Dayton, Ohio
I prefer gravity bleeding but if your going to use a machine I would use the Motive. I have tried the vacuum bleeder and didnt care for it. The vac bleeder can as was said above suck air in around the lip seals and it will sometimes trip the switch inside proportioning valve.
If you have a bubble bath going on you better let it sit until all those bubble condense or you will never get them out.
edit - if your getting lots of bubbles in the cup it could be coming from the threads of the bleeders also.you can try wrapping threads with teflon tape to seal that up.
If you have a bubble bath going on you better let it sit until all those bubble condense or you will never get them out.
edit - if your getting lots of bubbles in the cup it could be coming from the threads of the bleeders also.you can try wrapping threads with teflon tape to seal that up.
Last edited by ...Roger...; Aug 13, 2009 at 06:49 PM.
Team Owner
Joined: Jul 1999
Posts: 65,492
Likes: 230
From: Orange Park Florida
simple, takes nothing special other than a shop compressor and a drill....
hammer on the wheel cylinders to shake bubbles out...I have never found that to be a problem, but it's been reported....
Race Director
Joined: May 2006
Posts: 16,528
Likes: 53
From: Dayton, Ohio
I didn't even use a extra, drilled two 1/16 holes in the top, and filled m/cyl...put on the lid per usual...apply pressure from compressor to the hole....forces fluid through system, nice and clean...make sure m/cyl stays full, and one caliper per end and side is open at a time....when it drips....close it off and do the other....
simple, takes nothing special other than a shop compressor and a drill....
hammer on the wheel cylinders to shake bubbles out...I have never found that to be a problem, but it's been reported....
simple, takes nothing special other than a shop compressor and a drill....
hammer on the wheel cylinders to shake bubbles out...I have never found that to be a problem, but it's been reported....
Melting Slicks
Joined: Aug 2006
Posts: 3,429
Likes: 20
From: Kingston Ontario
Melting Slicks
Joined: Aug 2006
Posts: 3,429
Likes: 20
From: Kingston Ontario
Race Director
Joined: Apr 2000
Posts: 17,654
Likes: 190
From: Who says "Nothing is impossible" ? I've been doing nothing for years.
I replaced everything and tried gravity bleeding and I got nothing out of my rear calipers. I also used the hand pump and nothing. I then disconnected the rear line right at the master cylinder and nothing was dripping out. If it is not dripping out of the master cylinder it certainly won't be dripping out of your calipers.
I took the MC off and bench bled it properly this time and sitting on the bench it leaked brake fluid out of both the front and rear ports. I then put it back in the Vette and tried gravity bleeding again but still nothing out the rears. I then used the vacuum pump and withing seconds fluid was coming out. So two points here:
1) If your MC isn't bled properly and fluid doesn't leak out both ports you are wasting your time, maybe the Motive pressure bleeder can overcome this I don't know.
2) The rears may have trapped air in the calipers so tapping them or using a vacuum gun helps the fluid along as it also has a longer way to go
I took the MC off and bench bled it properly this time and sitting on the bench it leaked brake fluid out of both the front and rear ports. I then put it back in the Vette and tried gravity bleeding again but still nothing out the rears. I then used the vacuum pump and withing seconds fluid was coming out. So two points here:
1) If your MC isn't bled properly and fluid doesn't leak out both ports you are wasting your time, maybe the Motive pressure bleeder can overcome this I don't know.
2) The rears may have trapped air in the calipers so tapping them or using a vacuum gun helps the fluid along as it also has a longer way to go