2007 Explorer Pedal to the Floor

[tsum16]

I am stumped...

I was gifted a 2007 Ford explorer Eddie Bauer edition and it needed some brake work. The pedal was always soft and went to the floor when I received it but went ahead and dumped some money into parts to see if I could get it back to normal.

So far I have:
- Replaced rotors
- Replaced pads
- Replaced all calipers
- Replaced brake master cylinder
- Replaced brake power booster
- Performed several ABS bleeds
- Bled the lines so much I've gone through at least a gallon of fluid

Brake pedal STILL goes straight to floor when vehicle is on. The vehicle does brake but it travels a good bit before stopping. Fresh out of ideas, anyone else experience a similar issue or was able to resolve it?

 

[94Eddie]

Sometimes a failing rubber brake line can cause a loss of line pressure and a low pedal. What happens when you pump the brakes?

 

[tsum16]

Sometimes a failing rubber brake line can cause a loss of line pressure and a low pedal. What happens when you pump the brakes?

When pumping the brakes it gets pretty hard. Even tried bleeding the vehicle while fully started but the pedal still goes to the floor and only allows for a half inch to an inch of extra space when holding the pedal to crack and bleed. No visible signs of the lines being compromised and no leaks anywhere.

 

[94Eddie]

When pumping the brakes it gets pretty hard. Even tried bleeding the vehicle while fully started but the pedal still goes to the floor and only allows for a half inch to an inch of extra space when holding the pedal to crack and bleed. No visible signs of the lines being compromised and no leaks anywhere.

The rubber line won't lose fluid. It will expand and cause a loss of pressure on the first pump or two. When pumping the brakes does the pedal slowly go down?

 

[tsum16]

The rubber line won't lose fluid. It will expand and cause a loss of pressure on the first pump or two. When pumping the brakes does the pedal slowly go down?

I didn't particularly pay attention to that but perhaps the rear brakes did have some more give on the first pump or two compared to when we bled the front brakes. You think rubber replacement lines are needed or could the issue fall at the hard lines connected to the calipers? The vehicle does have almost 170k miles on it

 

[94Eddie]

I didn't particularly pay attention to that but perhaps the rear brakes did have some more give on the first pump or two compared to when we bled the front brakes. You think rubber replacement lines are needed or could the issue fall at the hard lines connected to the calipers? The vehicle does have almost 170k miles on it

The rubber lines being defective are about the only thing you haven't replaced that can cause this problem. Maybe you installed a bad master cylinder? You might be able to see the failure in the rubber line by inspecting them while someone else pumps the brakes.

 

[tsum16]

The rubber lines being defective are about the only thing you haven't replaced that can cause this problem. Maybe you installed a bad master cylinder? You might be able to see the failure in the rubber line by inspecting them while someone else pumps the brakes.

The right rear line bled but it didn't seem to have as much pressure as the front lines. I'll replace the rear brake hoses and see if that does the trick.

 

[94Eddie]

The right rear line bled but it didn't seem to have as much pressure as the front lines. I'll replace the rear brake hoses and see if that does the trick.

Another cause is there could still be air left in the system.