So the truck is broken again. . . .
After doing all of the above work we drove it on a 500 mile round trip. It drove great and averaged 18 mpg, braking was fantastic and no drama. Fast forward to 3 days ago while driving on the freeway the front passenger caliper locked up and started smoking, this is the one that was sticking and was rebuilt by me. The slide pins move very freely, and everything seems to be ok. Pistons push back as easily as the other side.
I would pump the brakes up and mash them hard, then go spin each wheel. The driver side spun very freely while the passenger side spun but had some drag. So I figured that maybe something else is wrong with the caliper so I said screw it and ordered 2 remmaned calipers (the red powerstops because reasons).
I installed the new calipers bled them properly and profusely. I pump them up as I did the others and mash it hard, go to spin the wheels and BOTH are LOCKED up. It will absolutely not turn what so ever. . .
They are installed correctly and the correct caliper is on the correct side (bleeders up) slide pins are greased and slide freely.
I cracked open the bleeder on the passenger side, it squirted fluid because it was under pressure and both, yes both calipers freed up. I did this a few times and it was the same every time. I then pumped them up again and unbolted the master cylinder from the booster and bam, with the bleeders closed the brakes freed up. I did this several times and it was the same every time.
I know that on the old-school master cylinder and brake boosters you needed to adjust the push rod, there are no adjustments that I can find on my vehicle or on the internet.
I took the master cylinder off and found that the pin on the booster that presses the master is loose, wobbles around, and moves in and out about 1/8" and binds when doing so. Reconnecting the master several times yielded different results each time, some drag, no drag, and locked up. So my assumption is that the pin is not supposed to move and that it's pushing the master cylinder occasionally causing the dragging? Does anyone know if its supposed to move in and out (loosly) about 1/8"? The super strange part is that it didn't do this with the old calipers, but that could be a coincidence that it failed during bleeding and was probably on the verge on failure and when the peddal was pressed all the way to the floor it was finished off. It could also be contributing to my low power if the brakes are dragging occasionally.
The master cylinder was replaced with a brand new Motorcaft unit less than a year ago so I wouldn't think that would be the issue.
Looking in the internet and the brake booster for the 09 is unique and discontinued literally everywhere. . . . I was hoping to buy one and compare but the only one I could find was a sketchy O'rielly unit that looks like garbage from the pictures and is special order.
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