2003 Expedition 4X4, 4.6, 125000 miles, pretty basic XLT

Going down the expressway, 60 miles from home (no tools, of course) hit the brakes 'cause of some idjit, released the pedal, brakes stayed engaged.

Tapped the pedal a couple more times, brakes engaged harder, were not releasing.

Determined it was both front brakes (don't know about the rears)

Up a road a little bit to a parts store, borrowed a wrench, cracked the lines at the master cylinder, quite a bit of pressure released, brakes freed up, bought the wrench in case it happened again (10 bucks!, but a lot cheaper than a tow truck), came on home with no problems.

2 weeks ago I'd replaced the booster 'cause it had a vacuum leak, and at the same time replaced the front pads and rotors. (yes, I know,you should only repair one thing at a time) After I did that, the brakes felt soft, even after bleeding, pedal would eventually go to the floor, thought maybe I'd pushed some dirt into the master cylinder when I compressed the calipers and cut a seal, got a rebuilt master cylinder, which is the one that didn't release. And the rebuilt master cylinder never did feel right, kind of soft, but it seemed better than the original.

When I bled the system after installing the rebuilt master cyl, never did get nearly as much brake fluid from the front bleeder screws as the rear per pedal pump.

But now I'm wondering, this all started when the booster was replaced, could the pushrod length in the booster be too long, not allowing the master cylinder to fully retract? I looked, but didn't see any adjustment on the booster when it was installed.

I've done a lot of brake jobs on the families vehicles over the years, never had one do this.

Any thoughts?

Thanks

Fred

 

It could just be a bad rebuilt MC.