Title sums it up. I was out of town for a week or so for Christmas, came back and my brakes were spongy. After bleeding four separate times, I have not found a leak or improved the braking. Today I got it to highway speeds and with no one around me, slammed the brakes and noticed the left side seems to lock up, but the right does not. It pulls to the left when braking at high speed. At low speed I can slam the pedal to the floor and it does not lock up. After writing that, maybe at highway speeds the wheels aren't locking up but are slowing down enough to cause them to skid on the pavement. Thoughts?

 

Is fluid disappearing?
Does it still have drum brakes? Maybe one of the rear cylinders is leaking.
How did you bleed it?

 

Yes, rears are drum brakes. I haven't noticed any leaks. The first bleed was counter clockwise starting with the front left. I realized that was wrong and the next three bleeds were done correctly right rear, left rear, right front, left front. I have since tried the "elephant stomp" and reverse in a parking lot and slammed brakes. After driving around and stomping on my brakes, I've noticed they are now locking up. I haven't had it at highway speeds since doing that but maybe that is all it needed. Thank you for your reply

 

Just out of curiosity, are the caliper bleeder screws on TOP? In case someone installed the calipers on the wrong sides. If they were installed backwards ya can't bleed all the air out. Might not be it, but worth a look to rule out.

 

Depending when they were last changed, if ever...the rubber flex hoses from the wheel well connection to the calipers cold develop dry rot and stretch or expand during hard braking. This allows uneven pressure to the front wheels and one wheel pulls. The same happens at the back axle flex segment but it reduced braking pressure to both wheels mostly evenly.

 

Thanks for the replies! Bleeder nips are up top. After standing on my brakes while off and reversing and slamming them, that seems to have reset the proportioning valve. My brakes are now locking up!

 

Not going to pull the proportioning valve to see if its dirty?

 

No, I wasn't planning on it. Just glad it's working

 

That definitely sounds frustrating, and you’re right to question whether it’s true lockup or just uneven braking. Spongy pedal after multiple bleeds usually points to air still trapped somewhere, often in the ABS module if the car has one. That can require a scan tool to cycle the ABS during bleeding. The pulling to the left suggests the right side isn’t contributing properly, possibly a seized caliper, collapsed brake hose, or contaminated pads/rotor. At low speeds, there may just not be enough force to show the imbalance. I’d inspect the right front brake hardware closely and also check for a failing master cylinder, which can cause a soft pedal without visible leaks.

 

Make sure your drums are adjusted correctly as well.