1973 05 Eagle fuel line one way check valve?

[Gary LaBombard]

Hey guys,
started up bus again yesterday, had to reprime the fuel system a little again but there may still have been air in the fuel line that did not get completely out after start up a couple of days ago.  I am not sure that this line will stay air free once the bus is run for a long time and then shut down.  I was toying around the thought of installing a Check Valve at the fuel tank to keep the fuel supply up to the primary filter at all times, Unless I let the tank run low or out of fuel, (Which I assure will not happen) after all this planning.  What is your opinion of doing this or is it overkill?? 

[luvrbus]

There should be a check valve at the primary filter,if the supply line is in good shape with no leaks it will prevent the fuel from leaking back to the tank,Detroit number 5122279 cost about 40 bucks 

good luck

[Gary Hatt - Publisher BCM]

I just recently installed a check valve on the rear of my Series 60 for the same reason.  I am also seeing air bubbles in the fuel filter so I assume I have a pinhole leak in the line which I need to look into soon.  But for now, at least it starts up much faster.

[Gary LaBombard]

Cliff, my inlet on my secondary fuel filter is 3/8", the DD check vlv you mentioned is spring type 1/4" fitting.  I can use fittings to increase the size but will the smaller id of the check vlv restrict fuel flow or am I worrying about nothing?  I did not order yet but will wait on your info.  I believe this will prevent any bleed back of fuel to the fuel tank and glad I mentioned it.
  here is link to actual part you mentioned:
https://store.reliableindustries.com/engine-parts/5122279-valve-fuel-supply-check-1-4-spring-type/

[luvrbus]

This the number for the 3/8th which is needed 5135308 sorry about that I have a time trying to remember the numbers off the top of my head lol I think it is old age 

[Gary LaBombard]

cliff, welcome to my world.  I am glad I asked you this and glad I thought of installing a check vlv.  I knew I could count on you.

OK, cliff, correct check vlv #5135308 ordered $36, Thanks again.

[Geoff]

I'm glad you found a 3/8npt check valve, I've never seen one.  The rest of the world uses 1/4npt check valves
  Every DD fuel filter housing I've seen uses reducing bushings.

[luvrbus]

I use 1/4 inch a lot because I have those but prefer the 3/8ths,I have never saw that many 1/4 inch on the filters,most buses have the 3/8th check valve at the bulk head