Got a fass 150 on my truck and in the package was a spring.
No mention of this in the instructions (yes, I read them for once!).
Is it an extra or for more pressure?

 

for more pressure.

 

what are the pressure #'s for the stock and extra spring?

 

Stock is about 15psi and the spring will give you about 19-21psi

 

i can see how that would give you piece of mind about the injection pump, but wouldnt that be detrimental to the flow? IIRC in a given space, if pressure increases, volume and speed decreases? Please correct me if i am wrong. Because i woundered about this spring for a while too, just never remembered to ask.
ALSO i did not read all the directions during install, so where does this spring go?

 

i can see how that would give you piece of mind about the injection pump, but wouldnt that be detrimental to the flow? IIRC in a given space, if pressure increases, volume and speed decreases? Please correct me if i am wrong. Because i woundered about this spring for a while too, just never remembered to ask.
ALSO i did not read all the directions during install, so where does this spring go?

 

The spring goes behind the return fitting(one that sends the excess to the fill neck).I have it in mine.Runs at around 20psi.Only drops about 2 psi under WOT.If you change it make sure the rubber ball gets put back in behind it.They will fall out sometimes or stick in the spring you are removing

 

Ahhh...that spring...i get alot of questions on that one!

Its a spring for the FASS 150/200-1008 & 45PSI kits (OR FASS 95/200-1008 & 50 PSI)). They share the same mounting package so that is pretty much a wasted part for your application.

Just throw it at someone or something!

For 150 GPH applications it will not work. It will cut off all return fuel to the tank and put the FASS on its high pressure relief in the T-Block. I would suggest anyone that has used this spring to change back to the one that came with it. We have a spring that will put the 150 GPH pumps at around 20 PSI if wanted....PS-1020.



Ive been working on getting them to make mention of that thing in the install instructions...but they are redoing them soon.....