Mechanics

BLED FRONT LEFT BRAKE (SPEED BLEEDER) BUT STILL GETTING AIR

1998 Saturn SL2 • 175,645 miles

I just overhauled all four of my my brakes- new wheel cylinders plus hardware for the back, cleaned and rebuilt the front calipers myself. Decided to go with speed bleeders as it makes it a one-man job. I bled everything in order but since I've been driving I notice my car pulls to the left when braking at a decent speed 40-55 mph. I correct it by steering and it goes away and the car rides straight. My brother says adjust the back brakes so I do until I get a decent drag with the drum on. I decide to bleed the front left and get a hose full of tiny bubbles that look like foam until I stop the pedal then they condense into larger air bubbles. I do this until I run out of brake fluid and have to stop (1AM) but decide to check for leaks: piston seal, banjo bolt, the works- everything looks good and the other three wheels bled out fine. And I'll admit- because this turned out to be a good thing- I wasn't exactly watching the master cylinder the whole time and heard that terrible sucking noise that means air just got sucked in. More fluid, pump pump pump, nothing, then the fluid goes through and starts coming out of the hose and, I'll be damned, more of the same air bubbles. What's going on here?
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Dandywolf
May 18, 2012.




How are you bleeding them? Gravity, helper pushing the pedal? If you're using a vacuum bleeder, you're sucking air around the threads of the bleeder screw.

If you catch it just as the master cylinder runs dry, that alone is not cause to bleed again at the wheels. Just pry one caliper piston back in to force the brake fluid and any air back into the reservoir. You can also fill the reservoir, then stroke the brake pedal a few inches very slowly a couple of times. When you push it, the brake fluid will go down, then the air bubbles will tend to float back up. When you release the pedal rapidly, the brake fluid rushing back will wash the air bubbles back into the reservoir.

As for the brake pull, check that fluid will bleed from all four wheels. If you find no fluid coming out from one front wheel and the opposite rear one, I have a fix for that.

Caradiodoc
May 18, 2012.
I used speed bleeders on the front brakes and the first time I bled them (all four after the rebuild) the front left caliper kept spewing out the tiny bubbles until it LOOKED cleaned. I used speed bleeders because you can do it by yourself- there is a small spring and ball that lets out air and fluid but doesn't let anything back in. Now, I have the same kind of speed bleeder on the right side and regular bleeders on the back (because they don't make speed bleeders for the back. Anyway, the other three worked out fine and I used the same hose so I know it's not that I'm using too big a hose and letting air in. Also, I turned the speedbleeder only a quarter turn- they tell you right on the packaging to only go a quarter or half turn. By the way, I had already pushed the piston and pads back in wiht a C-clamp so I couldn't do what you suggested. I'll try all four again but everything's brand new and I just bled everything within the last couple weeks. But I'll give it a try and get back to you. Thanks for the input. Is Saturntech9 around?

Tiny
Dandywolf
May 18, 2012.
Did someone say my name iam right here. So your only getting air out of the front calipers bleeder screws?Also you rebuiltthe front calipers?Let me ask you this are the bleeder screws on the front calipers towards the top right now or the bottom?

Saturntech9
May 18, 2012.
I'm not familiar with speed bleeders. Do you have to remove the bleeder screws to install those tools or is it just a fixture that attaches to the existing bleeder screw? Either way, I'm 99 percent sure you're pumping the brake pedal and getting bubbles sucked back in around the threads. The clue is the "tiny bubbles". Air coming down from the master cylinder will be big bubbles. Once you have clean fluid coming out, just let it gravity-bleed for a few seconds. Tap the caliper too with a wrench to dislodge any small bubbles that might be sticking to the casting.

Just to make mention, you will not hurt anything by using a c-clamp to press the pistons back into the caliper housing, but you should never NEED a clamp to do that. I always pry the pistons in with a large flat-blade screwdriver before I remove the caliper. If I can't do that, there's a ring of crud on the piston and it must be cleaned off during the rebuild or the caliper must be replaced. We used to rebuild all calipers and wheel cylinders in the '80s but today a rebuilt caliper costs less than a new piston.

Caradiodoc
May 18, 2012.
The bleeder screws are toward the top. I put the calipers/brackets back based on what was stamped on them; L for left (driver's side) and R for right (passenger side).
Speed Bleeders are bleeder screws with a spring and ball inside them so fluid and air come out but they won't let anything back in, so you can do a one-man operation. Or so they say. My brother is on his way to help me; he's convinced I'm getting the tiny bubbles from around the threads but speed bleeders are designed to prevent that and it didn't happen on the other side.
Saturntech9, why do you ask if the bleeder screws are up or down?

Tiny
Dandywolf
May 18, 2012.
He asked cuz every once in a while someone will mix them up side-to-side. That puts the bleeder screws on the bottom so you have to tip the car upside-down to get the air out! (You know that was sarcasm; don't really try that).

Caradiodoc
May 18, 2012.
Yes cardiodoc is correct thats why I asked had a guy that worked with me at the saturn dealer. He replaced the right frint caliper couldnt get it to bleed. He was wasnt there the next day car was still there so I had to look at it. He installed a left front on the right front.I would try bleeding it with a helper I saw the one man bleeders. Oem lisle etc make them only problem is when you release the pedal there is a chance for air to be sucked back in thru the threads of the bleeder. Have him do ten pumps then hold it then crack the bleeder then close the bleeder etc. Start at the right rear then left front. Then left rear then right front. That should take care of the air if you dont have any other issues. Let us know how it comes out.

Saturntech9
May 18, 2012.
Yes, the bubbles must have been from the threads (why do they bother making speed-bleeders then?) When we did the two-man way it worked like clockwork, all fluid, no bubbles. What a pain in the neck. So anyway, it's done and all is cool so thanks you guys, I'm glad you're there when I need you. Take it easy, have a good weekend.

Tiny
Dandywolf
May 18, 2012.
Glad to hear you got it to bleed after all family always works great to help you bleed.I just did a master cylinder and rear wheel cylinders on a 2002 SL1 had my sister help me bleed it lol. Worked great she is well experniced at bleeding brakes. To answer your question why they make the one man bleeder to make money lol. There are lots of tools I have bought over the years to suppose to make my life easier lol. Some worked some failed and some kinda worked. Read the amazon reviews on that one you bought its biggest complaint was the hose blowing off the nipple. Remember were always here for you if you need us.
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Saturntech9
May 18, 2012.

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