Gravity bleeding
Thread Starter
Instructor
Joined: May 2003
Posts: 220
Likes: 0
From: Hilton Va
Gravity bleeding
I have seen quite a few post on gravity bleeding brakes. I did a search and could not find the answer to this question. If you gravity bleed, do you open all the bleeders at one time or do you open one at a time? If one at a time, what order??
Drifting
Joined: Oct 2004
Posts: 1,259
Likes: 7
From: Ontario
Originally Posted by onaqwst
i did one at a time...... this way the fluid doesn't all of a sudden run dry........ helped out alot..
b
b
Drifting
Joined: Sep 2004
Posts: 1,532
Likes: 4
From: Fairview Heights Illinois, near Saint Louis MO, STL C3 Shark
I just plead with my wife to do the brake pedal pumping and your done real quick. I have an itch to drive it after mods/repairs so I can't "wait" for gravity bleeding.
Racer
Joined: Nov 2000
Posts: 290
Likes: 0
From: Omaha, NE
Start with the caliper that is farthest from the master cylinder and do one at a time. This way you can keep the cap on the master cylinder(loosely) and keep it full without scurrying around. It sounds **** but anytime glycol brake fluid is exposed to air it will absorb moisture so I always start with a new, sealed bottle of DOT3 or 4 and keep the reservoir covered as much as possible. Use clear tubing and a clear jar to catch the old fluid. You will see when new stuff is coming out. Take your time and don't let the MC run dry or you'll have to start all over. Good luck.
Le Mans Master
Joined: Oct 2002
Posts: 5,714
Likes: 6
From: Silver City NM
St. Jude Donor '05-'07
Do they gravity bleed the lunar lander??? Note that gravity bleeding will
NOT let you know if you have a weak caliper or brake hose. You might
want to jump into the 21st Century and pick up one of these:
http://www.motiveproducts.com/
Dep
P.S. Bobs77vet wears GRAVITY BOOTS!!
NOT let you know if you have a weak caliper or brake hose. You might
want to jump into the 21st Century and pick up one of these:
http://www.motiveproducts.com/
Dep
P.S. Bobs77vet wears GRAVITY BOOTS!!
Race Director
Joined: Jun 2000
Posts: 10,024
Likes: 658
From: FL
Originally Posted by DJ Dep
Do they gravity bleed the lunar lander??? Note that gravity bleeding will
NOT let you know if you have a weak caliper or brake hose. You might
want to jump into the 21st Century and pick up one of these:
http://www.motiveproducts.com/
NOT let you know if you have a weak caliper or brake hose. You might
want to jump into the 21st Century and pick up one of these:
http://www.motiveproducts.com/
Check the Motive Prroducts Instructions. 10 PSI is what they recommend. All you are doing is forcing fluid through. You WILL NOT find a weak hose or caliper with 10 PSI. 
After all brake systems run in the 100's if not 1000's of PSI level. Heck air pressure is 14.7 PSI at sea level.
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
2027 Corvette vs The World: Every Model vs Closest Competitor
Joe Kucinski
10 Most Common Corvette Problems of the Last 20 Years!
Joe Kucinski
5 MOST and 5 LEAST Popular Corvette Model Years in History!
Joe Kucinski
2027 Corvette Buyer's Guide: Everything You Need to Know!
Joe Kucinski
10 Things C8 Corvette Owners Hate (But Won't Tell You)
Joe Kucinski
10 Best Corvettes Coming to Barrett-Jackson Palm Beach 2026!
Brett Foote
Every Corvette Grand Sport Explained! (C2, C4, C6, C7, & C8)
Joe Kucinski
Grand Sport & Grand Sport X Launch Alongside All-New 535hp LS6 V8!
Michael S. Palmer
5 Reasons Bad Drivers Crash & 5 Ways to Avoid a Costly Mistake!
Joe Kucinski
Le Mans Master
Joined: Oct 2002
Posts: 5,714
Likes: 6
From: Silver City NM
St. Jude Donor '05-'07
Originally Posted by SteveG75
Check the Motive Prroducts Instructions. 10 PSI is what they recommend. All you are doing is forcing fluid through. You WILL NOT find a weak hose or caliper with 10 PSI. After all brake systems run in the 100's if not 1000's of PSI level. Heck air pressure is 14.7 PSI at sea level.
I found two bad calipers by using the Motive bleeder. This mirrors the experiences of MANY others who have used the pressure bleeder.
Sorry....practical results destroy your "theory".
Dep
Race Director
Joined: Jun 2000
Posts: 10,024
Likes: 658
From: FL
Originally Posted by DJ Dep
And I will counter that with another
I found two bad calipers by using the Motive bleeder. This mirrors the experiences of MANY others who have used the pressure bleeder.
Sorry....practical results destroy your "theory".
Dep
I found two bad calipers by using the Motive bleeder. This mirrors the experiences of MANY others who have used the pressure bleeder.
Sorry....practical results destroy your "theory".
Dep
If you did, my bad. I'll just apologize now.
Last edited by SteveG75; Jun 8, 2005 at 09:21 PM.
Le Mans Master
Joined: Oct 2002
Posts: 5,714
Likes: 6
From: Silver City NM
St. Jude Donor '05-'07
Originally Posted by SteveG75
Then those were pretty bad calipers. Here is a question for you. Did they leak under gravity bleeding? Did you even try gravity bleeding? If you only do it one way that is not evidence of the fact that your method is the only way to find a leak.
If you did, my bad. I'll just apologize now.
If you did, my bad. I'll just apologize now.
No they didn't leak with just pedal pressure.
I'm glad they DID leak under pressure bleed, as I'd hate to find out at the end of a 1/4 mile that I had failing brakes.
I never said this is the only way to find a leak. I'm saying that gravity bleed or vacuum bleed will NOT show this type of leak.
Dep
Le Mans Master
Joined: Apr 1999
Posts: 6,134
Likes: 46
From: Raleigh North Carolina
Originally Posted by DJ Dep
Yes I did a gravity bleed. No they didn't leak after gravity bleed.
No they didn't leak with just pedal pressure.
I'm glad they DID leak under pressure bleed, as I'd hate to find out at the end of a 1/4 mile that I had failing brakes.
I never said this is the only way to find a leak. I'm saying that gravity bleed or vacuum bleed will NOT show this type of leak.
Dep
No they didn't leak with just pedal pressure.
I'm glad they DID leak under pressure bleed, as I'd hate to find out at the end of a 1/4 mile that I had failing brakes.
I never said this is the only way to find a leak. I'm saying that gravity bleed or vacuum bleed will NOT show this type of leak.
Dep
Pressure bleeder..... 30 PSI... leak.
What am I missing? Need a lesson in the "new" physics.
Edit... I'm going to "theorize" here for a change...
When you "pedal bleed", with the bleeder open, you only develop a small percentage of total brake pressure, and only for an instant per pedal pump.
When you pressure bleed at 10 to 30 PSI... the pressure is constant over a much longer period of time as compared to a single pedal pump.
The time factor using the pressure bleeder is what enabled you to see the leak... which you would have not seen normally until after you had driven the car for a while.
Plausible?
Last edited by Tom454; Jun 9, 2005 at 07:30 AM.
Le Mans Master
Joined: Oct 2002
Posts: 5,714
Likes: 6
From: Silver City NM
St. Jude Donor '05-'07
Originally Posted by Tom454
Something is not making sense here... pedal pressure... mega PSI..... no leak...
Pressure bleeder..... 30 PSI... leak.
What am I missing? Need a lesson in the "new" physics.
Edit... I'm going to "theorize" here for a change...
When you "pedal bleed", with the bleeder open, you only develop a small percentage of total brake pressure, and only for an instant per pedal pump.
When you pressure bleed at 10 to 30 PSI... the pressure is constant over a much longer period of time as compared to a single pedal pump.
The time factor using the pressure bleeder is what enabled you to see the leak... which you would have not seen normally until after you had driven the car for a while.
Plausible?
Pressure bleeder..... 30 PSI... leak.
What am I missing? Need a lesson in the "new" physics.
Edit... I'm going to "theorize" here for a change...
When you "pedal bleed", with the bleeder open, you only develop a small percentage of total brake pressure, and only for an instant per pedal pump.
When you pressure bleed at 10 to 30 PSI... the pressure is constant over a much longer period of time as compared to a single pedal pump.
The time factor using the pressure bleeder is what enabled you to see the leak... which you would have not seen normally until after you had driven the car for a while.
Plausible?
I confess I DID have the pressure on for a while as I did the rear brakes first and the front calipers were the ones that were bad. So yes, VERY plausible.
Thanks Tom
Dep
Pro
Joined: Nov 1999
Posts: 520
Likes: 5
From: Front Range
Never really had any issues using the gravity bleeding method... usually you won't need a fancy tool to tell you your calipers are leaking. Regular and thorough visual inspection is the key here. Also, pay attention to your brake dive. If braking in a straight line (assuming your alignment and tire pressure is good), the car should not pull to one side or another. Test this regularly.
You could just as easily invest the $50 or however much that pressure bleeder costs in a set of Russel speed bleeders, also proven to be effective in one-man brake bleeding.
$.02
the blonde weasel
You could just as easily invest the $50 or however much that pressure bleeder costs in a set of Russel speed bleeders, also proven to be effective in one-man brake bleeding.
$.02
the blonde weasel
Burning Brakes
Joined: Sep 2001
Posts: 1,166
Likes: 0
From: Tulsa Ok
Originally Posted by DJ Dep
Yes I did a gravity bleed. No they didn't leak after gravity bleed.
No they didn't leak with just pedal pressure.
I'm glad they DID leak under pressure bleed, as I'd hate to find out at the end of a 1/4 mile that I had failing brakes.
I never said this is the only way to find a leak. I'm saying that gravity bleed or vacuum bleed will NOT show this type of leak.
Dep
No they didn't leak with just pedal pressure.
I'm glad they DID leak under pressure bleed, as I'd hate to find out at the end of a 1/4 mile that I had failing brakes.
I never said this is the only way to find a leak. I'm saying that gravity bleed or vacuum bleed will NOT show this type of leak.
Dep
Le Mans Master
Joined: Oct 2002
Posts: 5,714
Likes: 6
From: Silver City NM
St. Jude Donor '05-'07
Originally Posted by FeedVaal
This might be because there WAS NO LEAK. The pressure bleeder caused the problem. If many share those same results, I'd throw that pressure bleeder in the trash.
Dep
