Raycon fuel filter problem

[mkinney716]

I installed a new 500 Dual filter and when I fill the filter housing with fuel, close the top and seal then when I engage the fuel pump, somehow I'm getting air into the filter housing. I even tried taking fuel direct from a 5 gal tank. I cannot get the fuel to come through the filter. all I'm getting is air. Is there another fitting that I'm supposed to close. I cannot find one but will take any suggestions. My fuel pump is after the filter.

[Nicholson58]

This can be a problem if the filter is high in the system. Do you observe the fuel level falling if you pour diesel into the open housings? If so, you will need to find a way to prevent them draining back into the tank while you close and seal them. Valve? We have an electric boost pump just for pressurizing the fuel system and filling the Racors. I run the pump until fuel leaks out of the top cover and then seal them. On this system there is a valve to direct the suction pipe to the pump and the pump to the filter. After it’s filled, I can open a vents at the injectors to bleed air.

[skipmac]

If you are getting air into the filter housing even if drawing directly from the 5 gallon tank then there must be a leak in the Racor somewhere.

Did you install the o-rings between the top housing and the tops of the filters?

Do you see bubbles anywhere?

See any drips or leaks?

What about the hoses? I have had a hose with an invisible pinhole leak that let air into the system.

If you can't track down the leak then try pumping the fuel into the filter with the outlet closed so they filters are under a slight pressure. Don't overdo it.

[mkinney716]

I have the electric fuel pump after the filters. Should this be moved to before the filters?

[skipmac]

Originally Posted by mkinney716

I have the electric fuel pump after the filters. Should this be moved to before the filters?

All the boats I've owned the pump was after the primary filter (the Raycor) but before the secondary filter, usually a small can on the engine block.

[jkishel]

Look for a little orange o-ring on the tee-handle that threads into the housing and holds down the cap, it is often overlooked.

[mkinney716]

There is a mechanical pump on the engine and an electrical one after the Racon filter. I have a 3.5 gal day tank as well as 2 110gal fuel tanks. The way I have it configured is as follows.
Main tanks go to selector valve then to Racon. From there it goes to electric fuel pump then to selector valve with feeds either day tank or direct to engine. From day tank goes to selector valve to engine or from electric fuel pump to engine. When using day tank, it’s all gravity feed to engine. Filter is above tank level.

[mkinney716]

I finally fixed the problem. After tearing everything apart, it turns out that both fuel pumps would not pump unless primed first. I purchased a new one that will self prime up to 48” and it is working as it should.

[Compass790]

Originally Posted by mkinney716

I finally fixed the problem. After tearing everything apart, it turns out that both fuel pumps would not pump unless primed first. I purchased a new one that will self prime up to 48” and it is working as it should.

Thanks for posting your solution & glad you got it sorted.
What sort of pump did you buy?