03 f150 brake problems., brakes stop good the petal go to floor.

I think you need another mechanic.

Forgot no brake light on and when it goes to the floor it sound like air escaping

If, when you picked up the car, the brakes were good, then began going to the floor, you're getting air into the system at some point. Check the level of the brake fluid and see if you are loosing any.

Never lost any break fluid even on the original master cyl. the brakes won't right when i picked it up. the service center said he did not know what else to do and i needed to get another opinion on it. he wanted to try a 1100 dollar fix without knowing what wrong.

The brake pedal going to the floor indicates a few possibilities. There is air in the system. Air is compressible resulting in the pedal going to the floor. The other possibility is that the piston inside the master cylinder is allowing brake fluid to pass by the seal when the pedal is pushed. This happening on more than one new cylinder is remote. Question: Each time you received the vehicle back from the service center, was the brake pedal acting as it should? Or was it "to the floor" right out of the center?

There is another remote possibility. When a master cylinder is removed you will see a short shaft sticking out from the booster with a screw inserted into the end. This is an adjustment for the travel of the pedal prior to the piston being pushed and applying pressure to the brake system. If this screw got turned inward (somehow), making the distance from the head of the screw further away from the piston, then the pedal would have to be travel further before contact was made with the piston and applying pressure to the system.

AS i stated before the brakes stop the truck fine .it is when it is stopped that the brakes start to ease all the way to the floor. you can let the brake petal back up and it holds a few seconds then ease to floo r again.

This is the reason i took it to start with.

OK, the pedal holds, but slowly goes to the floor. Here are two possibilities. There is an internal leak within the master cylinder. There are two sets of seals on the piston. When pushed the fluid stops the vehicle but the fluid is being pushed past the seal backward toward the booster. Since the master cylinder has been changed this could be the problem, but the original problem is why you brought it to the shop in the first place, right? If the master cylinder has been changed more than once I doubt this is the problem. Second. One of the seals is bad within a caliper. Since the seals suppose to hold hydraulic pressure, it will hold in the fluid, but it maybe sucking air when the pedal is released. Try bleeding your own brakes. If there is air in the system at any wheel check all hoses for cracks. This is going to be a process of elimination one wheel at a time working back to the master cylinder.

Needs a HCM . Hydraulic Control module . All so know as ABS Module . It has a internal leak.

I have the same problem .... my mechanic said its most likely the ABS module ..... very expensive part , like $ 1000 from ford .... he tries to get a second hand unit for about half .... has had to fix a bunch of them .... mine is a 2003 with 234 k on it .

I got a 2004 Ford F-150 heritage, mine was doing the same thing, bought a used ABS pump with the module for $ 149.00 from eBay. Just make sure you get the right one. Put it on in about a hour. Fixed my problem. Ken wells. Old retired mechanic.

This has helped me, but now to get the FORD DEALERSHIP SERVICE DEPT TO Believe me about the ABS situation !!!!! Been a month since they started working on my truck, about to call Ford and say I’m switching to CHEVY!!!

I have had a similar problem in the past and it was the power brake booster. The way I was taught to check it. Holp the brake pedal down with your foot then let up just a little and if it goes to the floor that it what it is. I have replaced several threw the years with the same problem.

I had the same problem, change out abs pump, any good mechanic should be able to test it.

My issue is, I had to rebuild the rear differential. I figured what the hell, I'll change brake calipers while i am at it. after all was done, my only problem left is, I've bled the brakes 6x each caliper, and with the truck started, my pedal goes straight to the floor. when driving, I can pump it 3x and it's enough to stop the truck. This wasn't an issue before I started all of my maintenance.all the fluid had dripped out. Hence the reason I bled each caliper 6x. Please Help!!!!

I'm having the same issue I can pump the brakes solid when its not running but as soon as I start the truck with my foot on the pedal it falls right too the floor

I'm in the same boat. Weve changed all the brakes and bled them, changed the master cylinder, brake booster, ABS pump, done a full fluid flush, basically everything for the brakes as been replaced. We can get compression and a hard brake with the truck off. When we turn it on, pedal goes to the floor. Still trying to figure it out.