Wrong rotors? Rubber brake lines collapsing inside acting as a check valve? I had that problem...
Rotors fit, just one was slightly too tight on the hub, I fixed that by grinding it but it’s still tight. All rubber brake lines were replaced about 2 years ago with all motorcraft lines. Master cylinder is also new motorcraft. I found the culprit.
You did not mention the parking brakes. Did you remove the rotors and check them?
Parking brakes were replaced when I did the last brake job. Inspected them this go around and they are good and not dragging.
I found the culprit I’m pretty sure… the passenger side both front and rear were stiff and the slide pins did not slide easily at all. Adding to that one of the front calipers had a hole in the boot that allowed stuff in there causing it to stick.
Torn boot. It had some milky fluid in there along with some sludge.
Left set is drivers side, right is passenger side.
I used the white grease that came with the raybestos pads on the passenger, then ran out and used the purple prematex on the driver side. Taking them apart the ones with the white grease included with the brakes were stiff and extremely difficult to move, the side greased with the permatex purple was still butter smooth.
The inside of the driver side rear rotor was extremely worn out compared to the outside and was the worst one of all of them.
I really hate that I had to use parts store stuff, but a set of Duralast rotors and brake best semi-metallic pads made a world of difference! Gone is the semi-squishy pedal! It’s rock hard and stops a million times better! The Duralast rotor also fit the wheel hubs way better and tightened right down with no issue. My original rotors came with the truck and I had them turned and reused them. But because I needed them the day of this time it cost me $500…. If I had time to order them I would have went with a really nice kit for the same price but oh well.
Also power is better. Up top it’s great, but in the lower rpm’s it still seems lacking. It also has its moments of sluggishness. I’m data logging a bunch of parameters and will post back if I don’d anyone of interest.
Edit.
I deep cleaned the MAF as well as the throttle body. Installed a new set of motorcraft plugs (the old NGKs seemed OK and were only at .047). then I used Forscan to reset all adaptive tables. After all of that it now drives way better then it did. There seems to still be some pulsing and issues here and there but that could be from my trans. I did some datalogging so I will have to look into it.