2002 FST - No brake pedal when Engine is running and no codes for ABS. What am i missing?

[GO BILLS Jake]

I'm struggling for answers and hope someone can help. My son's 2002 Sport Trac has never failed him (been to Toronto, Montreal, Boston, Syracuse, NYC, DC in the last year) and we decided to replace brakes, rotors, pads, brake booster, shocks, etc. to get another 100k and pass PA state inspection.

Brakes were bled, no air, no leaks. Hard pedal and pressure when engine is off, but once the truck is running the pedal goes right to the floor and stops the truck ONLY at the very bottom. YouTubed it and saw ABS modulator could be bad but wouldn't that throw a code? I'm willing to replace anything but not willing to load the parts cannon and fire away. He's got another road trip planned this weekend but not with brakes in this condition.

What could this be? Have you had a similar situation and how did you fix? TIA for all advise.

Signed,
Stuggling to stop in PA

PS - photo for asthetics when we bought it. Found truck on death row waiting to be crushed for scrap in 2019. Rebuilt engine took care of that and has been AMAZING ever since.

 

[1hitwonder23]

I am having the exact same problem on my 2004 , any luck with yours?

 

[Phil Frady]

You could put your old brake booster back on. I'm thinking there may be an adjustment with the plunger between the master cylinder and the booster. Otherwise bleed the breaks again with a tool that will activate the antilock break module to get any air out of it.
I think mine does that but I cant remember since I loaned mine out a few months ago.

 

[my red sta]

How are you bleeding the brakes?
Old school pump the pedal, or a power bleeder?
Micro bubbles of air easily get trapped in abs modules. Or air trapped between chambers in the master cylinder?
A power bleeder will help get these out.
I've never had this problem on a Ford before, but I have had it on my Subarus.

 

[GO BILLS Jake]

OK so the results are in.........Calipers were installed upside down by my son and I NEVER picked up on it. Was so dam proud of the kid for doing all the work without me I simply did not focus on the most basic issue at hand.

Regret the delay in response and KISS method works with issues like this. Brakes not almost throw him through the windshield they are SO NEW. He's had to get use to the "new" pedal. LOL. Thanks for the feedback everyone as you guys ROCK! Love this page

 

[swshawaii]

You'd be surprised how often left and right calipers get mixed up. Happens on EF quite often. That's why it's advised to replace one side at a time. Had one hack refusing to check after being told several times. After struggling for one week he said the bleeders were on the bottom. Will never bleed all the air out that way. IIRC, the calipers are also marked L & R. Brake bleeders ALWAYS on top. Glad you caught it.