Filter head check valve question

[expensivehobby]

Hi all,

I have been reading as much as I could, and I couldn't find a definitive answer to the question I have. Is the return line check valve ball and spring that I've seen referenced integral to the brass screw-in fitting? Or, is it separate? What does it look like? I pulled the fitting and didn't see anything.

Thanks in advance

 

[icanfixall]

The brass fitting found in the 7.3 filter heads is the check valve. they should not flow back into the filter. Only allow trapped air to leave the filter head and return to the tanks. There are 2 differant sizes also. I "usually" collect them when I find them in the wrecking yards. Oregon Fuel Injection sells them and the smaller of the two is really cheap. I have found them in the uhaul seller section on ebay too for around $6.00. You will find that seller by the name utechcenter... When I got my truck many years ago this fitting was not on my filter head so I ran like that for years. It was a problem sometimes after changing a filter because all the trapped air needed to leave thru the injection pump.. Not good but it worked ok. Don't let anyone tell you the fuel from the return line system goes back into the filter thru this valve.

 

[expensivehobby]

Thanks. I actually already bought the replacement one from the U-haul guys as part of an order. Changed it out along with the schraeder as part of my electric fuel pump install. Having some issues getting it started, and came across the mention of a ball and spring. Thought that I maybe lost those or something.

Fuel is definitely leaking down, and trying to trace down the cause, so now I'll move on to the next potential culprit.

 

[racer30]

I pulled three filter heads apart and only one had a verry soft spring and check ball about .25" in behined the return line from the filter head. the filter head part# 1809433c1G It also had three barbs on the fitting. The other two had only a two barbs and no check valve at all. You could hold up the fitting and see right through it. The hole is verry small so it will return some fuel to the tank at all the times. The one with a check valve will keep air from getting into the filter head when the engine is not running. Seems to me it must have been a improvement made sometime in production. I wont be using the stock filter head on my MH swap. I am using a Racor 900 with a 2 micron filter and a electric pump.