Can the fuel primer pump from a C7 be used for a 3116?

[Reworked LMTV]

Can the fuel primer pump from a C7 be used for a 3116 with the appropriate adapters to the fuel lines?

Fuel Filter Adapter Head with Hand Primer for LMTV FMTV and MRAP Caiman

Fuel Filter Adapter Head with Hand Primer for LMTV M1078 M1079 M1080 2 ½ Ton Trucks FMTV M1083 M1084 M1085 M1086 M1087 M1088 M1089 M1090 M1091 M1095 M1096 5-Ton Trucks and MRAP Caiman NSN 2910014928072 PN RK22140

www.easternsurplus.net

 

[hike]

The 3126 uses this one, 445R10. I am pretty sure the 3116 and C7 are all the same. It is not a CAT specific part, it just needs to pull and hold fuel up from the tanks.

Racor 445r10 fuel filter/water separator

FUEL FILTER/WATER SEPARATOR

www.racorstore.com

 

[Reworked LMTV]

The 3126 uses this one, 445R10. I am pretty sure the 3116 and C7 are all the same. It is not a CAT specific part, it just needs to pull and hold fuel up from the tanks.

Racor 445r10 fuel filter/water separator

FUEL FILTER/WATER SEPARATOR

www.racorstore.com

That's kind of what I thought. Fitting sizes are different though.

 

[Ronmar]

That's kind of what I thought. Fitting sizes are different though.

Shouldn’t be different. The filter boss is 3/8” NPT, with 3/8-JIC6 male adapters. The fuel lines all have JIC-6 female ends…

 

[fuzzytoaster]

They are the same. I've pulled fuel primer pumps from donor engines for other FMTVs of all years.

 

[Reworked LMTV]

Shouldn’t be different. The filter boss is 3/8” NPT, with 3/8-JIC6 male adapters. The fuel lines all have JIC-6 female ends…

I don't know if you can see it in this pictures, but fitting from original primer pump is smaller that the new one. Maybe wrong primer part installed or variant?

They are the same. I've pulled fuel primer pumps from donor engines for other FMTVs of all years.

Puzzler... I put the old fitting next to the new primer in the pictures. The old fitting is small enough that it can just slide in. The part uses a washer / rubber O ring. I guess I can just order the larger JIC 6 to 3/8", but what about the washer/ O ring? What is the official name of that?

 

[hike]

I don't know if you can see it in this pictures, but fitting from original primer pump is smaller that the new one. Maybe wrong primer part installed or variant?

Puzzler... I put the old fitting next to the new primer in the pictures. The old fitting is small enough that it can just slide in. The part uses a washer / rubber O ring. I guess I can just order the larger JIC 6 to 3/8", but what about the washer/ O ring? What is the official name of that?

I ran into this when replacing our primer pump last spring, and forgot to mention last night! oops!

The military version used a 3/8 orb fitting which is 9/16-18 thread with the o-ring. The only place I found the mil-spec version required bulk orders. The commercial version available today onesey-twosey uses a 3/8 NPTF which is 11/16-18 thread as @Ronmar noted. You need new fittings between the boss and fuel lines to replace the male orb side with a male 3/8 NPTF. The NPTF fitting is tapered pipe, no washer or o-ring; just a little pipe dope.

Here is my final response to Rancor last spring which they confirmed:
So, dumb as a bump on a log.

The pump I am replacing has 3/8 orb fittings,( 9/16-18 ); though the 445R has 3/8 nptf fittings, ( 11/16-18 inch ).

Please confirm. No o-ring, Pipe sealant.

I can do that—

New fittings and pipe dope. She works and doesn't leak—