Air keeps coming out while brake bleeding
Thread Starter
Joined: Apr 2006
Posts: 3,740
Likes: 6
From: Las Vegas, NV
Air keeps coming out while brake bleeding
Well, I thought I had a leaking brake line on the passenger side front wheel. I changed it out with another one. Go to bleed it. Air bubbles just keep coming out. No leaks as far as I can tell in the front, including brake master. I know for a fact there are no leaks in the rear. I'll go double check the front and master in a liitle. What would cause air to keep coming out though? Seized caliper, bad master that is leaking internally? I just finished my front brakes and suspension and i can't go out for a joy ride 
If you turn your bleeder screw too far out it will appear as though air bubbles are coming out from inside but it just air going past the threads. Tighten everything back up and press on the brake pedal. If you have a spongy brake pedal then you still have air in the system. If the pedal feels nice and hard like my....... on a Saturday night then you are good to go. 
Thread Starter
Joined: Apr 2006
Posts: 3,740
Likes: 6
From: Las Vegas, NV
If you turn your bleeder screw too far out it will appear as though air bubbles are coming out from inside but it just air going past the threads. Tighten everything back up and press on the brake pedal. If you have a spongy brake pedal then you still have air in the system. If the pedal feels nice and hard like my....... on a Saturday night then you are good to go.
alright. I'll go do it again and see whats up. Thanks.
Joined: Jun 2008
Posts: 8,376
Likes: 28
From: Chino Hills, CA
You can also put a thin layer of lithium grease around the outside of the thread/caliper junction point; this will prevent air from bypassing the threads on the bleeder, and has the added benefit of making it easier to undo next time.
how are you bleeding the system? do you have someone pump the pedal and hold it while you open the bleeder? or are you using a vacuum bleeder? if your using a vacuum bleeder and you tighten the bleeder screw down immediately, as soon as you open it up again a couple bubbles will always seem to pop out.
whenever i replace a section of the brake system i always let it gravity bleed for sevral minutes before i even bother w/ the final bleeding at each corner. also when i use my vacuum bleeder i like to let the bleeder screw stay open and gravity bleede a couple of drips before i tighten it back down, just to ensure that air didnt some how find its way back in.
whenever i replace a section of the brake system i always let it gravity bleed for sevral minutes before i even bother w/ the final bleeding at each corner. also when i use my vacuum bleeder i like to let the bleeder screw stay open and gravity bleede a couple of drips before i tighten it back down, just to ensure that air didnt some how find its way back in.
Thread Starter
Joined: Apr 2006
Posts: 3,740
Likes: 6
From: Las Vegas, NV
You can also put a thin layer of lithium grease around the outside of the thread/caliper junction point; this will prevent air from bypassing the threads on the bleeder, and has the added benefit of making it easier to undo next time.
Sgt.Stinkfist how are you bleeding the system? do you have someone pump the pedal and hold it while you open the bleeder? or are you using a vacuum bleeder? if your using a vacuum bleeder and you tighten the bleeder screw down immediately, as soon as you open it up again a couple bubbles will always seem to pop out.
whenever i replace a section of the brake system i always let it gravity bleed for sevral minutes before i even bother w/ the final bleeding at each corner. also when i use my vacuum bleeder i like to let the bleeder screw stay open and gravity bleede a couple of drips before i tighten it back down, just to ensure that air didnt some how find its way back in.
whenever i replace a section of the brake system i always let it gravity bleed for sevral minutes before i even bother w/ the final bleeding at each corner. also when i use my vacuum bleeder i like to let the bleeder screw stay open and gravity bleede a couple of drips before i tighten it back down, just to ensure that air didnt some how find its way back in.
Ya, I got a vacuum bleeder.
Thread Starter
Joined: Apr 2006
Posts: 3,740
Likes: 6
From: Las Vegas, NV
Well I just got done rebleeding it and I had no air bubbles. Get everything back together and get ready to go test it. Start the car, press the brake and drops to the floor. Go to look at the master cylinder and see brake fluid slowly running down the booster. Guess new master is on its way.
Trending Topics
Very good tip, I'll make use of that next time I have to bleed brakes.
Thread Starter
Joined: Apr 2006
Posts: 3,740
Likes: 6
From: Las Vegas, NV
Ya this does suck. I still need to go get the master, I just woke up . Do I really need to bleed them at every corner? I'll let you guys know what happens after I get it installed.
. Do I really need to bleed them at every corner? I'll let you guys know what happens after I get it installed.
and not that it requires it but when replacing hte brake master cylinder, bench bleeding is a benifit and makes overall bleeding much eaiser. i bleed the brakes in all of my cars once every two years. i bleed until clean fluid comes out of each bleeder. makes me feel better if anything
Joined: Jun 2008
Posts: 8,376
Likes: 28
From: Chino Hills, CA
and not that it requires it but when replacing hte brake master cylinder, bench bleeding is a benifit and makes overall bleeding much eaiser. i bleed the brakes in all of my cars once every two years. i bleed until clean fluid comes out of each bleeder. makes me feel better if anything
and not that it requires it but when replacing hte brake master cylinder, bench bleeding is a benifit and makes overall bleeding much eaiser. i bleed the brakes in all of my cars once every two years. i bleed until clean fluid comes out of each bleeder. makes me feel better if anything
Leave A Message
Joined: Sep 2003
Posts: 1,454
Likes: 1
From: MN
what you can do when you install your new MC, is to crack all the lines that you snug up to the NEW MC once you have bench bled properly. Air is going to move to the highest point in a gravity bleed, so let all the lines drip a little and they will purge the air out. Then have someone pump the pedal ONCE. You've got ONE shot to remove the remaining air at the top of those lines and between the MC before the bubbles get pushed farther down.
Or you can bleed the whole system again...
Or you can bleed the whole system again...
Thread Starter
Joined: Apr 2006
Posts: 3,740
Likes: 6
From: Las Vegas, NV
Well another problem now. I go to bleed the brakes. Press the pedal halfway, then from there it falls to the floor. I take off the MC and I can pull like this rod out of the brake booster. Did that take a **** on me now? I'm about to roll my car off a cliff this is pissing me off.
That rod that goes through the booster really isn't held in by anything, it can move around if things are appart. Maybe when you had the master cyl off it came out of alignment or something. Hard to explain, but it should slide into place.
As for bench bleeding, I've never bench bled a MC and it always works fine for me.... strange..
As for bench bleeding, I've never bench bled a MC and it always works fine for me.... strange..
Joined: Oct 2005
Posts: 1,329
Likes: 8
From: SF Bay Area, California
Thats good to hear your brake troubles have been resolved as I was not so fortunate and needed a brake booster (which I believe rarely fail) which I didn't think was the culprit of my strange brake pedal feel. Leaking brake fluid from the rear seal on the MC leaked into the booster causing damage to the diaphragm inside.
Joined: Jun 2008
Posts: 8,376
Likes: 28
From: Chino Hills, CA
Brake fluid is quite destructive stuff; eats paint, eats many types of rubber, and once it becomes hydrated with water it promotes rust and attacks aluminum...
But it makes a great hand pre-cleaner! It'll get off many types of paint, glue, grease... and then it washes off easily with regular hand cleaner.
But it makes a great hand pre-cleaner! It'll get off many types of paint, glue, grease... and then it washes off easily with regular hand cleaner.