Here I am

Fass install Question/Fuel Pressure

Attention: TDR Forum Junkies
To the point: Click this link and check out the Front Page News story(ies) where we are tracking the introduction of the 2025 Ram HD trucks.

Thanks, TDR Staff

Aftermarket turbo?

fugimoto questions.

Alright Here goes..... I ordered a FASS about 8 months ago and i am finally getting ready to install it... . Well anyway my question is: I see that the FASS has a port on it for a fuel pressure..... I already have a Fuel pressure gauge and its tapped in Via banjo bolt on the injection pump..... Should i leave it where it is or move to the open FP port on the FASS? are the reading gonna be any different?



One other question i have as i am looking at install is can i filter my fuel 2 times? Meaning running the FASS filter/pump kit and run the main line into my stock OEM filter housing and filter it again? Will it hurt anything..... I know if i bypass the OEM filter i will loose my fuel heater and the water/sep light..... And another thing i was wondering is do i need to use and thread tape or sealer on the fittings into the FASS or anywhere else.....



If so what?



I have both thread tape the white stuff..... and i also have some permatrex sealant 2B... ..... THANKS
 
Last edited:
Doughboy21kd said:
Alright Here goes..... I ordered a FASS about 8 months ago and i am finally getting ready to install it... . Well anyway my question is: I see that the FASS has a port on it for a fuel pressure..... I already have a Fuel pressure gauge and its tapped in Via banjo bolt on the injection pump..... Should i leave it where it is or move to the open FP port on the FASS? are the reading gonna be any different?



One other question i have as i am looking at install is can i filter my fuel 2 times? Meaning running the FASS filter/pump kit and run the main line into my stock OEM filter housing and filter it again? Will it hurt anything..... I know if i bypass the OEM filter i will loose my fuel heater and the water/sep light..... And another thing i was wondering is do i need to use and thread tape or sealer on the fittings into the FASS or anywhere else.....



If so what?



I have both thread tape the white stuff..... and i also have some permatrex sealant 2B... ..... THANKS

You want to hook the fuel gauge as close to the injection pump as possible... . this way you know what pressure the pump is seeing. The stock fuel filter is a restrictive oem unit & the fass filters so well that you don't need the added filtration... ... just change the fass filter every time you change your oil & you'll have no worries. If you feel that you want to run it through the stock filter too..... get some upgraded fittings & do away with the restrictive banjo bolts or atleast drill out the holes in the banjo bolts bigger.
 
One other question i have that i'm not understanding is where is the fuel sender for the fuel gauge? How does that work when installing aftermarket fuel system?
 
Doughboy21kd said:
One other question i have that i'm not understanding is where is the fuel sender for the fuel gauge? How does that work when installing aftermarket fuel system?

The fuel sending unit is located inside of the fuel tank. I thought the 06 trucks still had the in tank fuel pumps? If so you need to drop the tank for the install & take the stock pump out & replace the stock pickup tube. I'm not sure about the 06, but I believe they do have the in tank fuel pump. That can get tricky messing around inside of the pickup/sending unit... ... if you aren't experienced. Some guys have installed the pickup tube & cut them too short & run the truck out of fuel before the fuel gauge read empty.
 
You don't take the sender out, it's in the tank. The fass hooks in at the top of the sending unit. I ran mine into the stock filter because it was where my fuel pressure gauge was and was way easier to do that then have to redo my pressure gauge. I have aeroquip lines, no banjos. You shouldn't need any sealer, but if you use some, us the paste. The tape gets eaten up by diesel and can fall apart and get in the lines. I think the pressure gauge should be hooked up after the filter (fass or stock depending), I don't care what the pump is putting out, I wanna know what my vp is gettting.

This is all on my 98. 5, I guess yours is probably different, I'm not sure how much. You may have to take the sender out to put in a bigger pick up tube of to take out the factory pump... . I don't have the time to look it up right now for ya or else I would.

Corey
 
Last edited:
Cummins724 said:
just change the fass filter every time you change your oil & you'll have no worries.





NO WORRIES??? My worrie would be the emptyness in my wallet from doing that :-laf



The FASS filters are hydraulic filters and you can go well over 10,000 miles before changing it.





Michael
 
I know the pump is in the tank and i know that you leave evrything AS IS in the tank..... On the FASS they give you a new draw tube so thats covered i just have to drill the hole in the tank and install it... ..... My question is how does the sender work if you unplug the stock lift pump?
 
you dont have to unplug the sender. you just cut the wire I think its the heaviest gauge black wire on the outter plug and tape it back. that disables the ground for the liftpump circut. but be sure to plug or dont unhook the supply line from the sender. it will leak fuel when you fill up the tank and it becomes really messy
 
I used Permatex #2 to seal the threads on the FASS (and every thing else that ever needs to be sealed on my truck for that matter). Never had a prob. I even use it to seal threaded plumding connections behind walls in my house!



The regular white teflon tape can break down over time when exposed to Diesel and will leak. If u "have" to use tape, use the yellow gas/petroleum resistant kind.



As for the sending unit and/or intank pump, I cant help as I have a 2001 and they are on a separate circuits.



Hope this helps,

J-
 
Highfinance97 said:
NO WORRIES??? My worrie would be the emptyness in my wallet from doing that :-laf



The FASS filters are hydraulic filters and you can go well over 10,000 miles before changing it.





Michael

That's what I was told when the shop installed my brothers fass on his 04. 5, but he goes by pressure drop & changes the filter when he loses pressure. I thought that was fass recommended... . Dunno! I guess that would get expensive... . call me Donkey! :D
 
Cummins724 said:
That's what I was told when the shop installed my brothers fass on his 04. 5, but he goes by pressure drop & changes the filter when he loses pressure. I thought that was fass recommended... . Dunno! I guess that would get expensive... . call me Donkey! :D





No big deal you didnt know, but now you do. :D

Glad i could help





Michael
 
Highfinance97 said:
NO WORRIES??? My worrie would be the emptyness in my wallet from doing that :-laf



The FASS filters are hydraulic filters and you can go well over 10,000 miles before changing it.





Michael





I agree... I put 40k on my last HF6604 without any noticeable change in pressure... and I know I ran some REAL CRAPPY fuel through it... search under my name and FASS and you'll see pictures of sand I got out of the separator.



My only thing is that you should drain the water separator every tank of fuel since the FASS has no provisions for a Water-in-Fuel light (that would be the ONLY argument for keeping the OE filter assembly in the loop).



steved
 
JCyrbok said:
I used Permatex #2 to seal the threads on the FASS (and every thing else that ever needs to be sealed on my truck for that matter). Never had a prob. I even use it to seal threaded plumding connections behind walls in my house!



The regular white teflon tape can break down over time when exposed to Diesel and will leak. If u "have" to use tape, use the yellow gas/petroleum resistant kind.



As for the sending unit and/or intank pump, I cant help as I have a 2001 and they are on a separate circuits.



Hope this helps,

J-





I would not use any sealant on the line that returns fuel to the tank since that fitting also houses the check ball and pressure regulating spring... you might want to change that some day... besides, it is sealed with an oring!



I used Hercules (?) blue block on the other fittings...



steved
 
Thats correct steve. I may have given the wrong impression with my last post. I DID NOT use any on the return as it is sealed with an o-ring and is thus not nessecary. I did do the intake and outlet though.



Sorry for the confusion.



J-
 
Back
Top