The ABS module monitors the vacuum pressure and if it is low then it activates the pump... now if the pump is defective it won't supply the added or should I say needed vacuum pressure which then would throw a code. The vacuum pump on the truck with Eco is only used for the brakes.

 

That's a good point. The vacuum pump is probably equally as important to the other vacuum driven systems such as hub activation, etc...

 

I am not sure but would guess that the other vehicles running the Eco have hydraulic brakes such as we would have had if they put the power steering pump on the Ecoboost truck! But according to the service manual the only thing the vacuum pump is used for is the brakes. I believe the hubs have there own system.

 

I know that when I was looking at the codes related to my timing chain failure, the service laptop does log low vacuum as an error code.

 

That is interesting. The SHO has an EPAS steering system just like our trucks so the brakes on that are not hydraulic. Maybe the F150 just needs all the boost it can get.

 

Must be then,, I didn't know if the cars had it but maybe it is because of towing?? They just might of put in on the trucks because of the amount of weight you can haul or tow

 

I'm having the same problem ford tired to tell me it was the high pressure fuel pump. I have had it with this truck.

 

That sounds like it. It makes the most sense.

 

I have the same issue 2012 ecoboost.

Took it in once and they couldn't replicate the problem so charged me $200 to clean the brakes.

Took it in again, 2 weeks ago, and am just told today that the vacuum pump is unavailable and noone can tell me when it will be. Have escalated it to Ford and told that the Regional Manager will get back to me in a couple of days. Nice to see it is urgent for them.

Have noticed on other forums that this is not uncommon for it to fail, and not uncommon for Ford not to have any in supply.

 

My pump has been dead for a while now. Died right when the timing chain went and I didn't have the $$$ to stick into the pump. It seems as if it only supplies vacuum upon start up. The engine must also be providing some vacuum as well. In 10k miles there has been maybe 3 times where I've notice the lack of brake boost, but the boost is back before you move 200'. Gets your attention because the pedal will go right to the floor.