Fuel filter supply line thread size..Cummins 250

[TechnoWeenie]

I've gone over what seems like 500 threads on fuel filter spin on mods... A bunch of people selling stuff... But no real data.

M934, nhc250...

I need to know the thread size of the supply (input) line into the filter housing as well as the input to the IP.

Any help would be appreciated. In a situation where the vehicle cant be parked long so I don't wanna disassemble everything to find out I can't get parts.

Already have filter base and filters, just need adapters for threads..

Thanks!

 

[MtnSnow]

The easiest thing to do is measure your needed lengths for hoses and hit the local hose shop (like Evco House of Hose) for the hose and fittings needed. I can tell you that it is normally a 5/8th compression at the IP and it is 1/2" male compression at the fuel tank pickup and then whatever size(s) you need at the filter head(s) you purchased.

 

[MtnSnow]

Oh and to just mention for informational purposes that the 8.3 CTA motors normally have 1/2" compression at their lift/primer pump instead of 5/8" like the NHC 250

 

[TechnoWeenie]

So the supply to the filter assembly (not the tank) 1/2 inch compression?

But if I'm changing it out... Might as well replace the supply from tank as well... Line is cheap.

I'll get a comprehensive parts list together and post it to help others in the future, as soon as I get this done.

 

[MtnSnow]

Yes from the tank outlet 90* fitting it is 1/2" compression. I personally highly recommend replacing all of the fuel line hoses (at least the suction side for sure from Tank to filter(s) to IP!) as like you said fuel line is cheap and you'll only be adding a few dollars per fitting. I personally switched all of mine out to Parker "push-lok" fittings as it makes converting over to the rubber fuel lines a breeze!

 

[plode]

Oh and to just mention for informational purposes that the 8.3 CTA motors normally have 1/2" compression at their lift/primer pump instead of 5/8" like the NHC 250

For informational purposes since we're sort of on the subject...what is the rubber fuel line size supposed to be on the 8.3CTA?

 

[MtnSnow]

1/2" for the 8.3 CTA. You can use either 1/2" or even 5/8" hose for either the 8.3 & NHC250 but the 1/2" will flow well over the amount needed for either motor