What is the CAT part number for 3116 fuel primer?

[juha_teuvonnen]

My M1083A0 came without a fuel primer, ad did many of the 3116 trucks. Does anybody know the part number for fuel primer? IIRC it's a fuel filter housing with primer built into it.

 

[simp5782]

My M1083A0 came without a fuel primer, ad did many of the 3116 trucks. Does anybody know the part number for fuel primer? IIRC it's a fuel filter housing with primer built into it.

It's not a cat filter head.

It's s Racor, # RK22140

 

[Wingnut13]

Thanks for the part number. My pumps check valve has failed, when I try and drain the sediment bowl the fuel drains back to the tank….

 

[Ronmar]

There is a flapper type bypass check valve on the bottom of the filter housing. When running fuel uses this flapper to bypass the primer bulb as it couldn't handle all that flow. The primer itself has its own smaller internal check valves, but both would have to fail to cause drain back…

The flapper can easily clog as there is no strainer/filter from the tank. If you remove the filter, the whole flapper and spring is held up in place with a Phillips head screw, and is easily removed for cleaning. Mine had a horse hair or insect leg in it when I got my truck. Easy fix…

 

[Wingnut13]

There is a flapper type bypass check valve on the bottom of the filter housing. When running fuel uses this flapper to bypass the primer bulb as it couldn't handle all that flow. The primer itself has its own smaller internal check valves, but both would have to fail to cause drain back…

The flapper can easily clog as there is no strainer/filter from the tank. If you remove the filter, the whole flapper and spring is held up in place with a Phillips head screw, and is easily removed for cleaning. Mine had a horse hair or insect leg in it when I got my truck. Easy fix…

Excellent news! I’d much rather fix than replace. I wasn’t sure if it was possible as the primer bulb is crimped on. Good to know the check valve parts aren’t under that. Thanks

 

[Ronmar]

Excellent news! I’d much rather fix than replace. I wasn’t sure if it was possible as the primer bulb is crimped on. Good to know the check valve parts aren’t under that. Thanks

Only the bypass check is accessible, the other 2 for the bulb are not. I did some 3116 fuel system videos over on Youtube. This first one covers how to check primer function. The second one is a system overview. One of my other vids shows what a fuel system air leak looks like using a primary pressure gauge…

 

[tacosauce]

Does anyone have a part number for the filter head without primer bulb?

Mine failed and I'd rather not deal with the bulb. It's easy enough to fill the filter with fuel and install it

 

[Wingnut13]

It’s easier, faster and less hassle to spin the filter off and verify there isn’t any debris under the flapper.

I did post up procedures and pics on what to do after I had posted on this thread.

Even if you replaced the head the first time you prime the system if there is debris in the tank it won’t work again. It’s an expensive way to do business.

However, if the primer is truly bad…. I don’t have the number you requested.

 

[Ronmar]

Does anyone have a part number for the filter head without primer bulb?

Mine failed and I'd rather not deal with the bulb. It's easy enough to fill the filter with fuel and install it

The filters point up, once full, they will stay full… The primer isn’t there to fill the filters anyway, it is there to fill the fuel lines and gallery in the head. If you have ANY sort of leak, the fuel lines and gallery will drain their fuel back to the tank. You will then crank and crank an expensive starter a long time to get the lift pump to fill the gallery and start the engine, if it even can… It is also there to get water/fuel out of the drain port at the bottom of the filter. Read the writing on the ring around the primer bulb…

if you just open the drain port on the bowl, nothing should happen as the weight of the fuel in the line is greater than the weight of the fuel in the bowl, and that flapper bypass valve at the top should prevent flow in that direction anyway. To get fuel out that water drain port, you must pump the bulb to add fuel to the filter which will then force fuel/water/debris out the bottom port.

Now if the fuel lines are full of fuel, and you open that water drain port, and it sucks in air, that is a dead giveaway that the flapper bypass at the top is not sealing properly as it is allowing fuel and air to flow thru it backwards as the weight of the fuel in the line flows back to the tank.

I have helped as many people with fuel issues as I have with electrical issues. And EVERY primer issue I have encountered has been related to that flapper being fouled. I only recall ever hearing of one other issue where that person actually encountered fuel leaking around the button(bad diaphragm)…

The primer should be able to do what I show in this video, if it cannot, it is most likley the bypass flapper which is fairly easily serviced… I should probably redo this video as it makes an assumption that the rest of your fuel system is sealed and the lift pump check valves are operating correctly. I do not believe the filter has another check valve on its output, so this test relies on the fact that the 2’ line between the primary filter and the lift pump checks and all associated fittings are capable of providing a seal… to rule those out you could remove the outlet hose fitting and cap that port with a finger while you push the bulb in with a thumb.

 

[Ronmar]

Here is a pic of the underside of this style primer/filter assembly. Mine has a hinged assembly, but still held in place with a Phillips head screw. Trust me when I tell you it is real handy to have a primer in the system…

 

[tacosauce]

Ok thanks for the input. It failed after I cleaned the flapper and tried to prime the line. Bulb never moved fuel when cracking the bleeder screw. Each time I filled the filter it would run for a few seconds then die.

Is this Racor part the only direct replacement, or is there a more common replacement?

 

[wheelspinner]

Ok thanks for the input. It failed after I cleaned the flapper and tried to prime the line. Bulb never moved fuel when cracking the bleeder screw. Each time I filled the filter it would run for a few seconds then die.

Is this Racor part the only direct replacement, or is there a more common replacement?

I have a few NIB units