5 ton stuck on the road!

[marksgarage2]

I know this is about a 5 ton, but we need help! My friends 5ton w/cummins is broke down. We changed the fuel filter, but lost prime to the filter. The in tank pump is not working. How can we get the prime back up to the filter without the pump working. Filling the filter is not working. Tried it 3 times. We need to get this back home asap. Thanks

 

[supermechanic]

Since when does a cummins need a tank pump?
On the top of the injector pump you will find a cap with a large screwdriver slot.
Under this cap is a screen filter.
Make shure the screen isn't filled with gunk.
CLEAN fuel can be introduced through this cap in an effort to reprime pump.
Have at it.

 

[rdixiemiller]

Mark
Get a primer bulb out of an outboard motor fuel line and put it in an area where you can get to a rubber fuel lineon the truck. They make big ones for the larger engines. I have driven a dumptruck home from the dirt pit with the primer bulb in my hand. I had to squeeze like mad, but I got home.
You can also get an outboard tank, fill with diesel, and put it on the hood. Not pretty, but it will bring you home.

 

[clinto]

You can also get an outboard tank, fill with diesel, and put it on the hood. Not pretty, but it will bring you home.

Ditto, I have done that......

 

[rmgill]

The M813s have a priming procedure that uses the cold start system to re-prime the fuel system to the highest point. Get a can or tank and catch the fuel that'll spill out of the flame heater side bleeder.

 

[marksgarage2]

We got it home. Will post tomorrow how. Thanks guys. I always know we can count on ya all. Mark

 

[CaptainRPM]

thanx for the help it was my 5 ton that was stuck it was the bleeder on the line before the filter was gettin air got it fixed and got it home but still seems to have a flat spot in it even after a filter change shifting from 3rd to 4th it kinda bogs and takes a bit to bring the rpms up its not always in 4th but seems like more goin into 4th than any other gear tho seems like it has gotten a lil worse after puttin on the 14/20s dont no tho any info will help

thanx gene

 

[Desert Rat]

Sweet ride Gene!

I've always loved those old Cummins 5Ts! Someday........................................

 

[73m819]

there is a BIG hole between 3 and 4 , on my 819 ,i fill the filter, then crank the engine, it primes it self every time (as long as the fuel filter vent and the filter drain is closed tight) cummins are real good for self prime as long as the fuel system is tight

 

[DaveP]

strange place for this topic but it's here so here goes. our XM818 lost it's prime the last two nights. it was running fine when it was parked and went out next day and no start. filled the filter and fired off. never had this problem before. this happend two days in a row. we will see in morning but my money is on no start. (without a fight that is) thought about putting a little air pressure to the tanks and watch and listen for leaks. this truck had the original fuel filter by passed and a after market filter mounted just under the top of the fender. this filter is about 12" above the injector pump but it worked before. any ideas ? for a bandaid fix i am thinking about a check valve.

 

[73m819]

sounds like a air leak

 

[DaveP]

removed fuel pickup line from tank and put 6 psi of air to it. nothing. no leaks or anything. not even any loss of air. very strange----. you would think if it allowed fuel to drain back into tank, there would have to be a leak somewhere? right? there is somthing i am missing here and it is prob'ly simple. like me. c'mon cummins owners help me out here if you can. im against the wall on this one.

 

[Rattlehead]

I don't know anything about that engine, but you could still have an air leak that won't show up under a pressure check. In other words, the leak is acting like a one way valve. If you have a Mightyvac, you could try and hold a vaccum on the system. If it leaks down, try to isolate it. I would start out at a low vac reading, else you might pull the leak path shut again.

 

[rice]

I had a similar problem on my deuce. On it the primary filter was stopped up. I had to bleed the air out of the filter everytime I cranked it. The booster pump was pulling a vacuum between it and the primary filter. When I cut it off it would suck air back through the return line. New filters cured the problem. Good luck.

 

[DaveP]

Rattlehead, good point on the pressure check flaw. never thought about it that way. will try vac. rice, only have one external filter and it's been changed several times recently. and the internal screen cleaned, and checked the o ring at the screen fitting. when it gets daylight i will see what i can find. thanks. Rattlehead that avatar is just to cool!!