Fuel Filter Assy Wont Prime

Good Day!
This is my first post to this forum.

About two months ago, I bought and replaced my Racor 3613 in-line fuel filter on my boat and found myself not being able to prime it back up to my motor. To make a long story short, I have replaced the bulb and have purchased two different complete fuel filter/housing assemblies. It seems that the only filter/assy that I can get primed and use is the one i bought from bass pro shops. Its there brand.
So, my question is why cant i get any other filter/housing assembly to work on my boat. I want to go back to a clear bowl filter so i can check for water.
Keep this in mind that I can prime the system w/o a fuel filter assy and only with the bass pro filter assy. Any advise would be greatly appreciated.

~Greg

Re: Fuel Filter Assy Wont Prime

You say that you are unable to prime the assembly but you you did not describe exactly what happens to the primer bulb when you sqeeze it. That would provide a good clue to narrow down the possibilities.

In general, if the primer bulb stays compacted after you squeeze it, that would likely indicate that there is a fuel line restriction up stream of the bulb. That could be in the tank, fuel line, or the assembly. If the primer bulb quickly expands back to full size after squeezing and it does not get firm, that would indicate that there is an air leak up stream of the bulb or a faulty bulb. If it expands quickly and also gets firm, then you have a real mystery on your hands.

Of course, you also want to be sure that the fuel lines are connected to the correct inflow and outflow fittings on the assembly.

Re: Fuel Filter Assy Wont Prime

Thanks for replying - hkeiner

I have tried every combination of things to include replace parts. Heck, i have spent over $200 dollars buying fuel filters & assemblies, hoses, fittings, portable tanks (3gal) and bulbs.

It is a true mystery. Try to explain why the only filter assy that I can get primed is a $25 bass pro shops special. When I try to prime any of the other assemblies that I have..the bulb expands and contracts and makes a slirping noise - like its sucking air. I would hate to assume that the problem with the other assemblies is that air is coming in at the filter housing/assy somehow on both. All of my buddies fish and have boats and they all scratch their heads as well. I am just gonna keep on tinkering with it until i get it resolved. Iam no outboard mechanic but I turned wrenches in the Army for 13 years. So, I will figure it out. Just need to trouble shoot some more. Thanks again!

Re: Fuel Filter Assy Wont Prime

When you stand on your head, it's easy to turn the drain petcock the wrong way.

PS, don't ask.

Re: Fuel Filter Assy Wont Prime

The problem does appear to be an air leak upstream of the bulb. Since the problem goes away with some of the filter assemblies, then the problem probably is with the filter assemblies that have the problem. The only place I can imagine an air leak occuring on an assembly would be at the fittings or at the seal between the housing and the bowl.

It would be pretty hard to confirm an air leak when the unit is installed since the air would be leaking in. If I were as frustrated as you and determined to find the leak, I would remove the housing and submerge it in a bucket of water and then force air in through the INFLOW fitting with the OUTFLOW fitting plugged and see if any air escapes, such as around the seal between the housing and the bowl. Just my thoughts...

Re: Fuel Filter Assy Wont Prime

hkeiner said:

The problem does appear to be an air leak upstream of the bulb. Since the problem goes away with some of the filter assemblies, then the problem probably is with the filter assemblies that have the problem. The only place I can imagine an air leak occuring on an assembly would be at the fittings or at the seal between the housing and the bowl.

It would be pretty hard to confirm an air leak when the unit is installed since the air would be leaking in. If I were as frustrated as you and determined to find the leak, I would remove the housing and submerge it in a bucket of water and then force air in through the INFLOW fitting with the OUTFLOW fitting plugged and see if any air escapes, such as around the seal between the housing and the bowl. Just my thoughts...

Click to expand...

You could do that in the boat by disconnecting the engine bayonet fitting, and the fuel line at the tank. Put about 10 PSI of air on the in line and spray soapy water on things till you get bubbles.

Re: Fuel Filter Assy Wont Prime

I have had the "O" ring on filters leak, make sure you put a good coat of oil the seal. Also, my Honda/Racor filter has a vent hole in the housing but I have never had a problem with it.
The filter housing doesn't care which side is in our out but the filter does. While it will stop junk/dirt hooked up backwards, it will not stop water. That is according to a Racor Rep.

Re: Fuel Filter Assy Wont Prime

Thanks, For all your advise. They are all very good ideas and I may try them out.

j-martin:
I think i will try your idea while standing on my head - LOL. What cha think about that?

Thanks again all. I will post back once i get it figured out.

~Greg

Re: Fuel Filter Assy Wont Prime

Well....I took the original Racor filter assemble....retaped and tighten'd the fittings...screw'd the filter and clear bowl back down on the housing...hook'd up the hoses and started to pump the bulb...this time it got hard as a rock.
So, i disconnected the fuel hose from the bulb on the motor side which releaved the pressure and then i started pumping again.....

Wu-laaaa....the darn thing filled up the filter...i reconnected the fuel line on the motor side to the bulb and primed it up....then ran the motor...no problem....

Don't ask me what it was that fixed it..flipp'n magic i guess.....but she's working.....Scratch your head again on that one.

Thanks again everyone...i didn't even get a chance to use any of you're troubleshooting tips....cause everything worked on the first try....