RLXXI

Not so on a 4WABS system, if a valve sticks it may only affect one wheel, there are 4 valves per wheel in the HCU, inlet, outlet, isolation, and dump which would be my last best guess, that or a defective caliper and/or hose. Just because it's new does not mean it's good.
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who_knos

Something is going on then.....everything is new, and still cooking pads. That being said when you install the pads how much force is used to install them? I like them to move with a breeze ....or with a feather...in context..lol. I work till they fit they way I want.

who_knos

Very true, in the way your thinking that would eliminate the MC.....I agree with that as well. New parts....not working Im 100% on board...and since its new them parts are always over looked.

RLXXI

The possibility of the HCU being the problem is extremely rare but it is a possibility.

The parts guy at my dealer would argue with us (tech's) when we gave him back a new part as a defect all the time, I got fed up with his attitude and showed him how to diag a concern using Ford's manuals to prove the part(s) were defective.

He never argued with us again.
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who_knos

In this day of age...anything is possible. I replaced a fuel spider on a 4.3 for preventive maintenance.....did the replacement...it ran 100 miles...put the old one in and ran fine...did a warranty for the 2nd..it ran worse yet...the sales rep said Ill get you another one...I was done with that brand....went a different route...never heard back for that problem....bad parts out the box is a very common thing, and it sucks....but still the truth......

Wingdreamer

Agreed, I'm not ruling out that the new flex hose isnt bad. They come with a metal mounting bracket that wraps around the hose that could easily pose a issue if the "crimp" around the hose is too tight. I'd love to throw another caliper and hose at it "just in case", but I always use the "test, dont guess" as a means of diagnosing and repairs. Thats why this is bugging me so much. I hate not having the answer!

who_knos

Hoses are cheap, and depending on where/when they was bought....Warranty both...one or the other...exchange the caliper and buy another hose in another brand/or different parts store. I did brakes on a old VW bug and got 3 bad wheel cylinders in a row....all would leak and after tearing them apart they all was missing different pieces inside...bought another brand from another place and had no problems.

Gudfish67

I am fighting the same left front issue. I just replaced calipers on both front wheels. Took for a test run and within 10 miles, the left (drivers) side started getting hot again. I have new hoses coming. Will keep you posted.

Straight6jeff

Had same issue on my 2010....left front wheel drag after a few thousand miles on new brakes. Pulled the caliper mounting bracket (where the pads sit), and mic’d the mount. Turned out the mount was machined a bit out of parallel.

new mount solved my problem.

Wingdreamer

When you replaced the calipers, did they include the mounting brackets (known as "fully loaded")? This ended up being my problem. The mounting bracket was worn out, and even with a new caliper, the caliper would "****" on braking, and bind, not fully returning. As a result, the brakes would drag on the left front wheel. I ordered another caliper, that included the bracket that mounts to the spindle, and a 4 year headache was finally fixed!