Brake Work Gone Bad

Been a bit but can’t find my answer anywhere yet.

This weekend went ahead and replaced my Brake Booster and Master Cylinder. Stock MS leaked and ended up killing my booster diaphragm.
Things went relatively smooth. New Booster holds vacuum. The new MS was bench bled as best possible. Install seamed to go well. I knew I had some air in the lines due to a squishy pedal, not too surprising. Went through and did a standard bleed through all four corners and was able to pull air out. Pedal felt good, so I check for leaks and buttoned it up for a test drive.
Made less than 1/2 mile before my brake pedal got stiff, only 0-1” of movement. By the time I made it a mile I knew I had an issue. Very touchy brake pedal and was having to give it some gas just to keep speed. Both front rotors are dragging. Pulled into a parking lot, sure enough, both front were locked up. Not wanting to risk it, I depressurized the brakes by a quick bleed in the parking lot, which thankfully is the same lot as our local 4x4 Shop. Drove it through the parking lot and left her there.

Now my assumption it air in the ABS system but this is new area for me. I don’t have the reader capable of ABS bleed. Anyone ran into this one? Am I missing something?

Cheers

BLACKJKU said:

Sounds like a problem with the rubber lines collapsing on the inside and not letting the brakes release.

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Now I have had that happen with the help of Jiffy Lube putting steering fluid in the MS in my old Isuzu. It was a progressive failure, 100s of miles. This was very abrupt but similar outcome. Hmm.

Cimmerian said:

This is why I never use quick oil change places for anything. I know Jiffy Lube has been pushing they do brakes now for the past decade but if I wouldn't trust them with something as simple as draining oil, I wouldn't trust them with brakes.

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That was the last time anyone touched fluids in any of my vehicles. I understand the MS and steering reservoir were very similar and close in my rodeo but damn that was an expensive experience.

Okay back to the problem, hopefully have her solved.
Something I was not aware of, adjusting the Booster Rod to get minimal gap between the rod and MS. I certainly had 1/16-1/8” of contact so the booster never let the MS bleed all the way down. Every cycle it just built pressure until it locked up. Another board member suggested I check this. Was able to limp the jeep home (after a parking lot bleed). Took a few tries to get the gap right but it was quick and worked great. Gap is set and all four corners release as they should.

Cheers

Hope this helps someone else from hitting this snag as well.