Questions regarding this gas tank

32sbct · Post by **32sbct** » Sun May 08, 2016 3:30 pm

This reproduction gas tank came with my M38. I remember by brother trading some parts for it at the Aberdeen military vehicle show probably about 15 to 20 years ago. There are no markings on it. Looking down on it from the top it is 18.75" wide. Viewing in from the side it is 7.75" tall. Does anyone know who made it?

My second question is on the sending unit. My jeep will be 12 volts. What sending unit can I use? The M38 is 24 volts and the CJ3A does not fit. Also what should I do about the vent line on the fuel filter assembly? My entire vent system is long gone. My engine is an MB with a glass topped fuel pump. Please let me know if you need any additional information. Any suggestions are much appreciated.

Marty

Hawkshadow · Post by **Hawkshadow** » Sun May 08, 2016 5:38 pm

- sending unit: check down in the forum. There is a recent thread addressing just this topic.

- vent: put a breather cap fitting like the fitting on your diff cover.

4x4M38 · Post by **4x4M38** » Sun May 08, 2016 7:50 pm

Does that CJ sender fit in the hole but the screw holes
don't line up? Does it have five holes? One hole is offset.
Just turn it until it lines up. Make sure the float and arm
doesn't hit anything.

It will register full, but will show empty before you are there,
so will always have gas left. Not necessarily a bad thing..

It does have to match the resistance range of the gauge you
are planning on using.

32sbct · Post by **32sbct** » Mon May 09, 2016 8:47 am

Brian,

Your reply made me wonder why my sender did not fit. I had ordered a CJ3A sender but it looks like the sender I was sent is a six hole model for the late CJ3A & CJ5. So it does not fit. I think the easy solution is to just buy a CJ3A model made for 12 volts. Thanks to all.

Marty

Post by **wesk** » Mon May 09, 2016 9:10 am

Marty,

I believe you will be disappointed when you find that none of the CJ senders match the military tank sender hole.

4x4M38 · Post by **4x4M38** » Mon May 09, 2016 3:46 pm

I have an old CJ3 tank with a nasty, non-working sender.
On a lark I pulled it out and tried it in my M38 tank.

I had to turn it until the holes lined up but it screws right in.

The only markings on it are:
SW
USA
Pat. Pnd.

Post by **wesk** » Mon May 09, 2016 9:25 pm

All five holes lined up and the float drops on the correct side?

4x4M38 · Post by **4x4M38** » Tue May 10, 2016 10:43 am

Yes,
The holes line up and the arm swings the same as 7524909.

Take care,

32sbct · Post by **32sbct** » Tue May 10, 2016 7:18 pm

I will be attending the Aberdeen military vehicle show on Thursday. I think I'll throw my tank into my Jeep Wrangler and take it with me. There will be many vendors there. That will give me a chance to see if I can find a sender that fits. What side of the tank should the float sit on? I'll let everyone know how I make out.

Marty

32sbct · Post by **32sbct** » Fri May 13, 2016 6:57 pm

Well I talked to numerous vendors at the Aberdeen MD military vehicle show. All of them said that none of the civilian CJ model fuel senders will work which is surprising because the gasket for them lines up perfectly with the six holes in my M38 tank. I think I'm going to use the CJ5 sender I already have since it is a 12 volt unit. The flat part that sits above the tank is large enough to drill new holes using a five hole gasket as a template. Since I already have it I figure its worth a try. If nothing else at least will will fill the hole.

Marty

4x4M38 · Post by **4x4M38** » Fri May 13, 2016 7:10 pm

Wait, your M38 tank has five holes?

32sbct · Post by **32sbct** » Fri May 13, 2016 7:51 pm

4x4M38 wrote:Wait, your M38 tank has five holes?

Sorry my bad. It's six holes.