Engine/Transmission (1994 - 1998) Fuel Heater Input Seal Replacement Question

[KOwens]

Hello again TDR Gurus,



Can anyone out there tell me what to use on my 1995 Cummins for a replacement seal on my fuel heater input line? The dealer tells me this part is no longer supported, and I will find out later tonight if my seal is defective.



Attached is a drawing they faxed to me. Item number (3) is the fuel heater input line and on the bottom of this fuel line is the seal.



Would an o-ring do the trick? And if so, what size?



Please help if you can.



v/r Kevin

 

[Joe G.]

I just realized that mine is not even on my truck anymore. I have changed my fuel system so that there is a tank selector valve that allows input to the fuel heater from my main tank or my aux tank. So this fitting has been replaced with a barbed fitting for hose. I still have my old line and fitting. If you would like a picture of the line, seal, and fitting email me at -- email address removed -- . A picture will show you have the thing is supposed to fit together.

 

[KOwens]

Hey Joe,



Email and PM sent to you.



v/r Kevin

 

[Vaughn MacKenzie]

KOwens, #3 is more appropriately called the fuel supply line, the primary line from your fuel tank. That square-cut rubber O-ring is impossible to source from Dodge or Cummins. . . been there done that. Believe me I tried. But it's a critical item because it'll cause you to suck air if not sealed well. I would take it and go to a hydraulic shop or some place with a good O-ring supply and see if they could match it.

Your second option is to get rid of the hard line and run a rubber fuel line from the metal line coming up from your fuel tank directly to the heater inlet. Remove the fitting into the heater and replace it with a 3/8 NPT-to-JIC adapter fitting, -6AN to be specific, then get a -6AN push-on (socketless) 90-degree fitting to put on the end of your rubber line and screw it onto your adapter. That's what I did on my '96.

 

[KOwens]

Thanks Vaughn,



Roger the square cut o-ring. Luckily, mine is still working OK. No air leak this morning after completing the re-assembly work on the banjo fittings atop the fuel filter housing. I like your idea of simply replacing that mess with a different "supply" line from the tank. Can you tell me more about the JIC set up you wrote about? Do you have any pictures I could look at? I'm not familiar with the type of connections you are describing.



Anyway, thanks for the info, as it stands right now, the truck is up and running!



Kevin

 

[Howard Durand]

Vaughn.



I am beginning to suspect an air leak in my system. No fuel leaks on the pressure side of the lift pump but each morning I have an engine miss and low fuel pressure for a short time on startup.

I did some work last year that required taking that connection loose and have been suspicious about the sealing washer ever since.

Since that part is not available I would like to replace it the way you did. I would like to echo Kevin's request for more info on the fittings you used.



Howard

 

[Vaughn MacKenzie]

Howard & Kevin, the socketless 90* fitting to use is Aeroquip 190516-6S
Aeroquip 90 degree elbow socketless fititngs

And the adapter fitting to screw into your preheater inlet
http://store.summitracing.com/partd...300068+4294906736+4294906753+115&autoview=sku

Now I can't speak for 100% certainty that the 90* fitting will be the right size to match the rubber hose you'll need to connect to your hard line from the tank, that's because when I did mine I actually did -8AN (next larger size) since I upgraded my entire fuel line. Just ask for -6AN fuel line and everything should fit properly. I am not sure about the PN for the fuel line but it's black and Aerquip should be able to tell you what you need if you call them.

Vaughn

 

[SFrey]

#3 is still avalible from cummins part # 3923090, it's the whole line though



scot

 

[Howard Durand]

Thanks Vaughn for the information.



When I recently replaced the hoses with a set from Foster Truck, instead of cutting them to fit, I used them full length with a loop to take up the slack.

I would guess there is enough hose attached to the feed line to reach the pre-heater. If that is the case, all I will need is a barbed fitting to fit the 3/8" hose.

 

[Shadrach]

... . That square-cut rubber O-ring is impossible to source from Dodge or Cummins. . . been there done that. Believe me I tried... .

I was doing a search about fuel heaters and came across your comment. The Cummins p/n for the oring on the end of the line is 3923194. Shadrach