I'm trying to bleed the brakes on my car. The fronts are done and no more air bubbles coming out, however the rears are giving me a problem. No matter how much I bleed them, there is still air coming out when I bleed it. I check the fronts and they are still fine, no air bubbles. Went through one full bottle of brake fuild and it's still got air bubbles. I looked at all the brake lines and there is no visible crack and no brake fluid dripping from anywhere. What could be wrong???

 

The air may not be actually coming out of the braking system but rather getting in around the sides of the bleed screw. Try to not turn it anymore than necessary to get the fluid to move. Is your car on a slope with the back end lower? This might make things worse.

 

xviper: Thanks for the quick reply. I'll try your advice tomorrow and see what happens. The car is up on four jackstands and on a flat area.

 

If you are level, you should be fine. I know that when I crack open the bleed screw too much, air will get in but it's not from the system. Just make sure you see clean fluid and then close it all off, top up the reservoir, pump the pedal a few times, go for a controlled test drive. I think you'll find they are fine.

 

Also, When you go to close off the bleed screw for the last time do it while someone is in the process of pushing down on the brake pedal and fluid is coming out of the bleed screw. The person pushing the pedal should have it stiffen up before it gets to the floor. I find this realy helps getting that last little bit of air out of the system.