M923A1 losing prime

M35A2-AZ · Dec 10, 2011

I have a M923A1 that was losing prime. I checked and checked for leaks and found none.
But GL damaged my fuel tank mount before I picked up the truck, so I removed the tank to repair the mount. Now that I had the tank off I removed the fuel pickup tube from the tank. The tube was about ready to fall out of the ninety degree fitting that screws into the tank. The solder joint was cracked, so I guess that was the leak I have been looking for.
I soldered it up, this time was silver solder and put it all back together.
Now the truck starts and runs great and does not lose its prime.

Barron · Dec 10, 2011

That's some dandy Troubleshootin'!

M35A2-AZ · Dec 10, 2011

You get lucky sometime.

rrrr · Dec 10, 2011

Glad you found the problem. Its always very satisfying to fix issues that are difficult

decodeme2 · Dec 10, 2011

I had the same problem, had to bend the line to get it out of the tank, once i soldered the line i had to cut it a bit to get it back into the tank, did not want to drop the tank to get it out and back in.
It drove me nuts too!..
I took the whole system apart and resealed every line. Still same problem!. Finally the fuel tank was the last part to check.. and it was the problem..
good job, i did not use silver solder..
Kevin..

M35A2-AZ · Dec 10, 2011

decodeme2 said:
I had the same problem, had to bend the line to get it out of the tank, once i soldered the line i had to cut it a bit to get it back into the tank, did not want to drop the tank to get it out and back in.
It drove me nuts too!..
I took the whole system apart and resealed every line. Still same problem!. Finally the fuel tank was the last part to check.. and it was the problem..
good job, i did not use silver solder..
Kevin..

Glad you found it. It made me happy when I found it!!!
:beer:

texasjake · Dec 10, 2011

Great troubleshooting and a job well done. :beer:

Derrickl112 · Dec 11, 2011

Thank you!! Thank you!! Thank you!!!! I have been having the same issue with my m936. This morning I pulled the tank off and wile I was unscrewing that elbow piece the tube fell off! I hope soldering back together will solve all my issues!

M35A2-AZ · Dec 11, 2011

Derrickl112 said:
Thank you!! Thank you!! Thank you!!!! I have been having the same issue with my m936. This morning I pulled the tank off and wile I was unscrewing that elbow piece the tube fell off! I hope soldering back together will solve all my issues!

Glad I posted my fix and it helped you out!! That is what I like about steel Soldiers!! :beer:

Derrickl112 · Dec 12, 2011

After putting the fuel tank back together, and priming the engine (which is a PITA) my truck is running on it's own again. I'm going to keep my fingers crossed, hoping I don't have any other problems. Thanks again for this post!

ARYankee · Sep 21, 2012

I had to replace my fuel line from the filter to the IP. I've been pumping forever to get it primed. Does it take a while to get to prime back? It is a PITA.

M35A2-AZ · Sep 21, 2012

ARYankee said:
I had to replace my fuel line from the filter to the IP. I've been pumping forever to get it primed. Does it take a while to get to prime back? It is a PITA.

If your priming pump is good it should not take too long to go from filter to the IP pump. Maybe 30 pumps.
Did you open the bleeder valve under the pump?
It can be a PITA.

When I replace the filter I put a little air pressure in the fuel tank to push it up to the filter faster.
If you have the vent line on the intake pipe you can do it there.

juanprado · Sep 21, 2012

ARYankee,

It is a pain. I poured diesel in the line and filled it up. I think I was able to get it started as I cranked and cranked the engine till it fired and bled the air off.

I personally think you need to keep the primer drain cock closed but the tm says to keep it open.

See the following thread:
http://www.steelsoldiers.com/5-ton-up/91210-m923-hard-start-any-slight-incline.html

Best of Luck [thumbzup]

ARYankee · Sep 21, 2012

Yeah I had the bleeder valve open. I followed the TM.
I have pumped more than 30 times

I ended up having to take the filter housing off to get that hose off and so it doesn't have much fuel in it. I guess I'll try to put some fuel in the line and see. I do appreciate the help guys.

ARYankee · Sep 21, 2012

I got it!!! Thanks for the assist guys! I checked my line because I was going to pour fuel in it and noticed there was fuel in it so I cranked on it a few times then it started. I never got anything out of the drain on the primer pump...

juanprado · Sep 21, 2012

Awesome!

I never did get anything out of that drain either!

M35A2-AZ · Sep 21, 2012

Farmallmilitary · Jan 6, 2013

The other day i tried draining water from the water fuel separator and nothing came out of either drain just air sucking. So i closed the valves and tried priming the system because i thought there was air in it. Tried pumping the handle and nothing happened. So i tried to start it and it started and ran just fine. Why couldnt i get anything out of the separator? I thought i could at least get fuel.

commandojeff · Jan 6, 2013

ARYankee said:
Yeah I had the bleeder valve open. I followed the TM.
I have pumped more than 30 times I ended up having to take the filter housing off to get that hose off and so it doesn't have much fuel in it. I guess I'll try to put some fuel in the line and see. I do appreciate the help guys.

Do you know which TM this is in? I would like to read about it in case I ever have to do it. Thanks!

ARYankee · Jan 6, 2013

It is in TM 9-2320-272-10, pg 3-27 Section e.

M923A1 losing prime

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