Thinking the rear brakes not braking properly on my 2014 PIU

[FordGuy2014]

Hello,

Thanks for taking the time to read this post.

Problem:

I've been having brake issues with my 2014 PIU for a while now. I will post a brief chronology below. It feels like the rear brakes are not braking properly and the brake pedal seems low and it gradually goes towards the floor. The front seems to dive down more than it should. I have tried to do panic stops and it feels like the car should be stopping alot quicker. Lastly, on most occasions, I have to pump the brake pedal two or three times to get a good normal pedal for stopping.

** All parts mentioned below are OEM (brownish box) and not the Motocraft line (red/black box). The same parts that are installed onto the police/emergency vehicles. **

Purchased vehicle August 08, 2019.

1) August 17, 2019 Replaced brakes on 4 wheels with OEM parts (front and rear rotors & pads).
2) April, 2020 Brake pedal feels low and it feels like the rear wheels are not braking. I have to pump the pedal to get good braking ability.
3) May, 2020 Bled brakes (normal conventional method). Felt okay for a day or two and then back to low pedal and front diving upon braking.
4) June 3, 2020 Replaced rear brake slider pins OEM thinking pins were seizing up. Still did not improve braking. Still have to pump brakes.
5) June, 2020 Front brake rotors started thumping and seemed to be diving more than normal during braking. Pedal still feels low and going to floor.
5) June 8, 2020 Replaced warped front rotors (OEM) under Ford warranty.
6) June 9, 2020 Brought vehicle into dealer to have braking issue verified.
Dealer road tested, checked Oasis, SSM, TSB, self ABS test and bled brakes (normal conventional way and ABS method), road tested again.
Vehicle seemed fine and braking well after leaving, but two days after the vehicle seemed to not be braking well again and with a low pedal and slowly going to floor.
7) August, 2020 Brakes still feel like not braking properly in rear with low pedal and still pumping pedal.
8) September 1, 2020 Replaced rear callipers (OEM) thinking calliper pistons not holding presure properly or jamming up. Properly bled brakes and at same time flushed out old brake fluid with FORD DOT 4 fluid. Pedal seems worse than before. Goes straight to floor. Drove car around for a few hours and got a bit of a better pedal that when started test drive.

So there you have it, Any help would be much appreciated. Maybe I can get lucky and a few Ford techs or engineers read this. I sent this list to my dealer and they are stumped.

Thank you,
Robert

 

[03WIExplorerLtd]

Hello,

Thanks for taking the time to read this post.

Problem:

I've been having brake issues with my 2014 PIU for a while now. I will post a brief chronology below. It feels like the rear brakes are not braking properly and the brake pedal seems low and it gradually goes towards the floor. The front seems to dive down more than it should. I have tried to do panic stops and it feels like the car should be stopping alot quicker. Lastly, on most occasions, I have to pump the brake pedal two or three times to get a good normal pedal for stopping.

** All parts mentioned below are OEM (brownish box) and not the Motocraft line (red/black box). The same parts that are installed onto the police/emergency vehicles. **

Purchased vehicle August 08, 2019.

1) August 17, 2019 Replaced brakes on 4 wheels with OEM parts (front and rear rotors & pads).
2) April, 2020 Brake pedal feels low and it feels like the rear wheels are not braking. I have to pump the pedal to get good braking ability.
3) May, 2020 Bled brakes (normal conventional method). Felt okay for a day or two and then back to low pedal and front diving upon braking.
4) June 3, 2020 Replaced rear brake slider pins OEM thinking pins were seizing up. Still did not improve braking. Still have to pump brakes.
5) June, 2020 Front brake rotors started thumping and seemed to be diving more than normal during braking. Pedal still feels low and going to floor.
5) June 8, 2020 Replaced warped front rotors (OEM) under Ford warranty.
6) June 9, 2020 Brought vehicle into dealer to have braking issue verified.
Dealer road tested, checked Oasis, SSM, TSB, self ABS test and bled brakes (normal conventional way and ABS method), road tested again.
Vehicle seemed fine and braking well after leaving, but two days after the vehicle seemed to not be braking well again and with a low pedal and slowly going to floor.
7) August, 2020 Brakes still feel like not braking properly in rear with low pedal and still pumping pedal.
8) September 1, 2020 Replaced rear callipers (OEM) thinking calliper pistons not holding presure properly or jamming up. Properly bled brakes and at same time flushed out old brake fluid with FORD DOT 4 fluid. Pedal seems worse than before. Goes straight to floor. Drove car around for a few hours and got a bit of a better pedal that when started test drive.

So there you have it, Any help would be much appreciated. Maybe I can get lucky and a few Ford techs or engineers read this. I sent this list to my dealer and they are stumped.

Thank you,
Robert

Find a good independent mechanic. Without driving it, hard to guess.

 

[BrettS.]

Either a leak (and accompanying air in lines causing spongy feeling) or bad master cylinder. Based on the symptoms I would replace the master cylinder. 100 bucks on RockAuto.

How to check:
Disconnect the brake tubes from the master cylinder.
Plug the outlet ports of the master cylinder.
Lightly apply the brakes and hold for 10 seconds. Release the brakes and then reapply with heavy force. If brake pedal height cannot be maintained, the brake master cylinder has an internal leak and a new brake master cylinder must be installed.
If brake pedal height is maintained, reinstall brake tubes and tighten to specifications. After installation, bleed the brake system.

With the vehicle in NEUTRAL, position it on a hoist.
Apply and release the brakes.
With the brakes released, attempt to rotate each wheel and check for any brake drag.
If an excessive amount of brake drag exists at multiple wheels, continue to Step 5.
If an excessive amount of brake drag exists at only one wheel, it indicates a possible seized brake caliper, brake wheel cylinder or parking brake component. Repair or install new components as necessary.
Check the brake stoplamp switch and the brake pedal free play to verify that the brake pedal is not partially applied.
Loosen the brake master cylinder nuts and position the brake master cylinder away from the brake booster.
With the brakes released, attempt to rotate each wheel and check for any brake drag.
If the brake drag is no longer present, install a new brake booster.
If the brake drag is still present, install a new master cylinder.

Removal
With the engine off, press the brake pedal several times to deplete the brake booster vacuum.
Remove the battery.
Remove the Air Intake pipe.
Disconnect the brake fluid level indicator switch electrical connector and detach the wire harness.
Disconnect the brake tubes from the master cylinder.
Cap the brake tubes and plug the master cylinder ports. NOTE: Make sure that the master cylinder-to-booster seal is removed with the master cylinder.
Remove and discard the 2 brake master cylinder nuts and remove the brake master cylinder.

Installation
Bench bleed the master cylinder.
Make sure that the master cylinder-to-booster seal is installed with the master cylinder.
Install the brake master cylinder and the 2 new brake master cylinder nuts. Tighten to 20 Nm (177 lb-in).
Connect the brake tubes to the master cylinder. Tighten to 22 Nm (16 lb-ft).
Connect the brake fluid level indicator switch electrical connector and attach the wire harness.
Install the Air Intake pipe.
Install the battery.

 

[FordGuy2014]

Either a leak (and accompanying air in lines causing spongy feeling) or bad master cylinder. Based on the symptoms I would replace the master cylinder. 100 bucks on RockAuto.

How to check:
Disconnect the brake tubes from the master cylinder.
Plug the outlet ports of the master cylinder.
Lightly apply the brakes and hold for 10 seconds. Release the brakes and then reapply with heavy force. If brake pedal height cannot be maintained, the brake master cylinder has an internal leak and a new brake master cylinder must be installed.
If brake pedal height is maintained, reinstall brake tubes and tighten to specifications. After installation, bleed the brake system.

With the vehicle in NEUTRAL, position it on a hoist.
Apply and release the brakes.
With the brakes released, attempt to rotate each wheel and check for any brake drag.
If an excessive amount of brake drag exists at multiple wheels, continue to Step 5.
If an excessive amount of brake drag exists at only one wheel, it indicates a possible seized brake caliper, brake wheel cylinder or parking brake component. Repair or install new components as necessary.
Check the brake stoplamp switch and the brake pedal free play to verify that the brake pedal is not partially applied.
Loosen the brake master cylinder nuts and position the brake master cylinder away from the brake booster.
With the brakes released, attempt to rotate each wheel and check for any brake drag.
If the brake drag is no longer present, install a new brake booster.
If the brake drag is still present, install a new master cylinder.

Removal
With the engine off, press the brake pedal several times to deplete the brake booster vacuum.
Remove the battery.
Remove the Air Intake pipe.
Disconnect the brake fluid level indicator switch electrical connector and detach the wire harness.
Disconnect the brake tubes from the master cylinder.
Cap the brake tubes and plug the master cylinder ports. NOTE: Make sure that the master cylinder-to-booster seal is removed with the master cylinder.
Remove and discard the 2 brake master cylinder nuts and remove the brake master cylinder.

Installation
Bench bleed the master cylinder.
Make sure that the master cylinder-to-booster seal is installed with the master cylinder.
Install the brake master cylinder and the 2 new brake master cylinder nuts. Tighten to 20 Nm (177 lb-in).
Connect the brake tubes to the master cylinder. Tighten to 22 Nm (16 lb-ft).
Connect the brake fluid level indicator switch electrical connector and attach the wire harness.
Install the Air Intake pipe.
Install the battery.

Hi BrettS,

Thanks for the reply!! Great info you sent me. I will definitely give this a go on the weekend and post back my results.

Thank you for the great step by step right up!!!

 

[16vcabman]

When I backed out the calipers for new pads, after getting done, I noticed that the ABS pump kicked on and moved the rear calipers back out. If you have any air in the brake system, you have to pressure bleed system. Air gets trapped in the ABS portion of the brakes. This requires a reservoir of fluid and about 30 psi in order to bleed system properly.

 

[FordGuy2014]

When I backed out the calipers for new pads, after getting done, I noticed that the ABS pump kicked on and moved the rear calipers back out. If you have any air in the brake system, you have to pressure bleed system. Air gets trapped in the ABS portion of the brakes. This requires a reservoir of fluid and about 30 psi in order to bleed system

Thanks for the reply. I think I will take it to an independent garage for a pressure bleed. I followed what BrettS suggested and even had the dealer reprogram the PCM and ABS back to manufacture specs. It seemed great for a while and 3 days after being parked... same problem.

 

[FordGuy2014]

Either a leak (and accompanying air in lines causing spongy feeling) or bad master cylinder. Based on the symptoms I would replace the master cylinder. 100 bucks on RockAuto.

How to check:
Disconnect the brake tubes from the master cylinder.
Plug the outlet ports of the master cylinder.
Lightly apply the brakes and hold for 10 seconds. Release the brakes and then reapply with heavy force. If brake pedal height cannot be maintained, the brake master cylinder has an internal leak and a new brake master cylinder must be installed.
If brake pedal height is maintained, reinstall brake tubes and tighten to specifications. After installation, bleed the brake system.

With the vehicle in NEUTRAL, position it on a hoist.
Apply and release the brakes.
With the brakes released, attempt to rotate each wheel and check for any brake drag.
If an excessive amount of brake drag exists at multiple wheels, continue to Step 5.
If an excessive amount of brake drag exists at only one wheel, it indicates a possible seized brake caliper, brake wheel cylinder or parking brake component. Repair or install new components as necessary.
Check the brake stoplamp switch and the brake pedal free play to verify that the brake pedal is not partially applied.
Loosen the brake master cylinder nuts and position the brake master cylinder away from the brake booster.
With the brakes released, attempt to rotate each wheel and check for any brake drag.
If the brake drag is no longer present, install a new brake booster.
If the brake drag is still present, install a new master cylinder.

Removal
With the engine off, press the brake pedal several times to deplete the brake booster vacuum.
Remove the battery.
Remove the Air Intake pipe.
Disconnect the brake fluid level indicator switch electrical connector and detach the wire harness.
Disconnect the brake tubes from the master cylinder.
Cap the brake tubes and plug the master cylinder ports. NOTE: Make sure that the master cylinder-to-booster seal is removed with the master cylinder.
Remove and discard the 2 brake master cylinder nuts and remove the brake master cylinder.

Installation
Bench bleed the master cylinder.
Make sure that the master cylinder-to-booster seal is installed with the master cylinder.
Install the brake master cylinder and the 2 new brake master cylinder nuts. Tighten to 20 Nm (177 lb-in).
Connect the brake tubes to the master cylinder. Tighten to 22 Nm (16 lb-ft).
Connect the brake fluid level indicator switch electrical connector and attach the wire harness.
Install the Air Intake pipe.
Install the battery.

Hi BrettS. Apologies for not replying sooner. I did what you recommended and even had dealer reprogram PCM and ABS modules. Then the brakes were great. But after 3 days being parked the pedal was low again. I will get it pressure bled by an independent shop. Thanks again!

 

[peterk9]

Any update on this??

 

[2012 Ford Explorer]

Is this the FPIU section? And i have never had that issue and i have a good feeling that the 5.0 beat the crap out of the front shocks so you may want to check those and same in the rear but the rear may be because something with the brakes is broken or smashed

 

[2012 Ford Explorer]

And i am jealous of the white interceptor i am about to get one because i like normal cars but the FPIU is an exception it just looks so damn good

 

[peterk9]

Is this the FPIU section?

Yes.

 

[2012 Ford Explorer]

Thank you mr peter i had to search it up on google then it showed me

 

[2012 Ford Explorer]

Nice pups too i had a german sheaperd