Obs fass

02POWERSTROKE7.3 · May 22, 2011

What's the difference in the fass for the obs and the superduty? Could i use a fass for the obs on my superduty? A buddy has one he is not going to use did not know if I can use it.

Whytry · May 22, 2011

Would the mount on the frame rail be different?

Powerstroked162 · May 22, 2011

FASS doesn't have a brand model designation on their pumps. Its all based off flow output. I believe we use a 150/180 in our trucks. Regardless, if you do run a FASS pump, you will need a regulated return. As well if you intend on still keeping both tanks functional in the truck, you will need some type of transfer pump setup from the back tank to the front.

As far as mounting goes, the mount plate for the FASS on the SD chassis trucks bolts to the e-brake cable tab on the frame rail. You can do the same thing with your truck, you will just need to trim the mount plate a little and drill new holes. It will hold up fine.

Let me know if you have any questions

cumminskiller · May 22, 2011

Just my opinion but you could run a air dog wich is internaly regulated and not have to full with a regulated return. Just use a distribution block in the center of the vally and feed all four ports of the head. That is the set up im currenty running on my obs. Works great and so far im only dropping about ten pounds of pressure @ WOT. But i think once i get rid of both tanks and selector valve and just run a single bronco tank i will be fine.

ITUKMOR · May 22, 2011

I too would recommend using anything other than FASS. FASS are designed for high flow low pressure. which is great on a cummins or dmax that has an injection pump. when you put these pumps on powerstrokes which like 55+ psi and love 70psi they will work fine for a while. they will however wear out early and you will be asking yourself why am I replacing this pump so often. as for a regulated return, ALL powerstrokes should run them. SD owner's should be required to install one before they get their plates registered! keep in mind the main reason for maintaining fuel pressure is not to keep from losing power, but for protecting the P&B's in the injectors. cause when they are not happy I promise you won't be either.

Tom S · May 22, 2011

cumminskiller said:
Just my opinion but you could run a air dog wich is internaly regulated and not have to full with a regulated return. Just use a distribution block in the center of the vally and feed all four ports of the head. That is the set up im currenty running on my obs. Works great and so far im only dropping about ten pounds of pressure @ WOT. But i think once i get rid of both tanks and selector valve and just run a single bronco tank i will be fine.

So you have no incorporation to bleed out air or do you not think that is an issue.

Aljay · May 22, 2011

Not a bigfan of the fass, I gave mine away .

Bruno2 · May 23, 2011

ITUKMOR said:
I too would recommend using anything other than FASS. FASS are designed for high flow low pressure. which is great on a cummins or dmax that has an injection pump. when you put these pumps on powerstrokes which like 55+ psi and love 70psi they will work fine for a while. they will however wear out early and you will be asking yourself why am I replacing this pump so often. as for a regulated return, ALL powerstrokes should run them. SD owner's should be required to install one before they get their plates registered! keep in mind the main reason for maintaining fuel pressure is not to keep from losing power, but for protecting the P&B's in the injectors. cause when they are not happy I promise you won't be either.

I thought the fass was designed for cummins anyways?

I would build my own rather than use one like fass or airdog.

Tom S · May 23, 2011

I have read quite a few Fass failure posts in the past.

cumminskiller · May 23, 2011

Tom S, You are correct once the system is open then yes the only way for air to get out is threw the injectors. But So far i havent seen any issues with it. I have had lines off once now and just cycle the key and it starts with no problems. We have run this setup on three truck so far and seems to work great.