What have you done to your 5 ton this week?

Cobbled together a cargo spare tire holder, or at least that's what I think this structure on the truck is for. Can't find it in the TM's, but it lines up with the lugs holes perfectly.
I used all thread a couple eye bolts, fender washers a 2X6 and 2X12 to isolate the tire from the bed. Holds the tire securely in place. Am I close?

I used it to haul my M1102 trailer full of junk to a local Military show/swap meet .

Small turn out due to Labor day wknd, but still fun, saw lots of people I don't get to see otherwise, and consumed some delicious Mexican food .

Here's some pics ...

Changed the oil and now the engine won't shut off "normally" that is.
I either have to use the emergency shutoff valve or repeatedly turn the battery switch on and off.
It's not a runaway, it's idling at 500RPM with no hesitation in the throttle.
It's just that the ignition switch, battery switch and dual battery kill switch won't shut it off. Everything starts fine, it's charging, airs up and the oil pressure is between 60 and 90. Used 7 gallons of 15W40 Rotella T4, replaced the filter, nothing leaking and the oil level is between Low and High when hot.
Did I jostle something removing the filter? A Protective Control Box issue? Oil Pressure Lockout Switch? Fuel Shutoff Solenoid?

@Wreckclues

Removing the electronic fuel shut off solenoid on my 5 ton and throwing it in the trash was one of the better mods I ever made, the manual cut off works fantastic .

Edit: Looks like my truck is newer/different than yours, I have the 8.3

I had that problem some years ago. I took the fuel shut off solenoid apart and cleaned it. A speck of dirt will cause them to stick open. Once it was cleaned, it’s been working fine. While I was having that problem I got tired of opening the hood to reset the manual shut off. I installed a spring to pull the manual lever back into place. I left that little mod in there in case I need it again.

Took a hammer to the solenoid and got the engine to shut off electrically, but now the engine is hard to start and runs rough. Figure the valve is only partially open now. Also noticed a leak in the manual shutoff. Found the TM to remove the solenoid and manual valve but can't find anything on the solenoid or valve themselves. What can I expect upon taking the solenoid apart? Anything that should be replaced or can I just clean the parts?
If I were to delete the solenoid how do I direct connect the manual shutoff to the pump or can I just gut the solenoid and leave the internal valve open?

Wreckclues said:

Cobbled together a cargo spare tire holder, or at least that's what I think this structure on the truck is for. Can't find it in the TM's, but it lines up with the lugs holes perfectly.

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yes, that is the OEM spare location on M39-series and M809-series 5T cargo beds

Wreckclues said:

What can I expect upon taking the solenoid apart? Anything that should be replaced or can I just clean the parts?
If I were to delete the solenoid how do I direct connect the manual shutoff to the pump or can I just gut the solenoid and leave the internal valve open?

Click to expand...

1: The solenoid is a simple item to clean up .. There is a spring in there (maybe two, it's been many years) but it comes apart and goes together easy , only about 3 pieces in there

At one time I had trouble with an M818 solenoid so i gutted it and ran it for a few weeks using the emergency pull to shut down .. The only "bad" part of that is being up in the seat the next day to crank it but forgetting to reach up under the inner fender plate opening to flip the shutoff lever to "run" position , no need to open the hood if you remove the appropriate under-fender access place , for lack of having a correctly-sized return spring on-hand..

2: As far as the emergency shutoff (manual) valve goes, I haven't had one of those apart but you should be able to remove at least the lever and retainer nut in order to clean up the stem and clean or replace the packing seal (maybe it's an Oh-Oh ring).. Some valves will allow you to remove the guts for cleaning, some don't .

For reference, this is what the guts looked like on my M813 manual shutoff:

Wreckclues said:

View attachment 931024

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PS; although it doesn't show on the TM illustration, your truck has a fuel solenoid bypass "screw" on it , it's at the front with knurled knob ... Some cummins 855's have it, some don't.. I don't recall which way it turns for bypass (in or out), but it would be opposite of what is is right now .. It was in bypass mode when i bought the truck, thus in order to see what that was all about I put it back into normal position and it worked as it should for years until now .. Just thought I'd put another PT-pump accessory factoid out there for you

Took the fuel shutoff solenoid apart and I'm not sure what I'm looking at.
Was expecting a spring, what I have is something akin to a wave washer enacting upon a diaphragm?
I assume when the electromagnet is activated the wave washer/spring is pulled flat allowing fuel pressure to move the diaphragm which mates to the valve seat on the valve body, allowing fuel to pass. I'm not sure if the "spring" is supposed to be free floating or attached to the diaphragm?
When enacted, the bypass screw msgjd mentioned, would push the diaphragm off its seat but in my case not by much as it had no effect on the fuel starvation problem I'm experiencing. Perhaps the problem is with the electromagnet or the connection to it. In either case I've ordered a new one from C&C Equipment.

Nice picture

Wreckclues said:

Took the fuel shutoff solenoid apart and I'm not sure what I'm looking at.
Was expecting a spring, what I have is something akin to a wave washer enacting upon a diaphragm?
I assume when the electromagnet is activated the wave washer/spring is pulled flat allowing fuel pressure to move the diaphragm which mates to the valve seat on the valve body, allowing fuel to pass. I'm not sure if the "spring" is supposed to be free floating or attached to the diaphragm?
When enacted, the bypass screw msgjd mentioned, would push the diaphragm off its seat but in my case not by much as it had no effect on the fuel starvation problem I'm experiencing. Perhaps the problem is with the electromagnet or the connection to it. In either case I've ordered a new one from C&C Equipment.

View attachment 931418View attachment 931418

Click to expand...

Maybe check continuity on that electromagnet where the wires would connect. Can't see in the pic.

Installed a STARK Crane with Cable Winch in the cargo bed primarily to raise and lower the spare tire...NOTE TO SELF: KEEP BOTH HANDS ON THE CRANK HANDLE WHEN LOWERING
Unit consists of an 1100lb boom with boat winch and a 3 ton hydraulic jack. The combination winch and jack sold me. The price, free shipping and color helped too. Easy installation, came with angle iron that can supposedly be used to mount it to a hitch receiver or the front bumper. Secured boom between tire and cab by hooking to spare tire mount.

Wreckclues said:

Was expecting a spring, what I have is something akin to a wave washer enacting upon a diaphragm?
I assume when the electromagnet is activated the wave washer/spring is pulled flat allowing fuel pressure to move the diaphragm which mates to the valve seat on the valve body, allowing fuel to pass. I'm not sure if the "spring" is supposed to be free floating or attached to the diaphragm?

Click to expand...

yes , the wavy washer is the spring that keeps the diaphram normally closed.. sorry i don't recall but i think the spring is free-floating , it should need freedom to lay flat under magnetism and return curvature .. It likely can't do that if it's "glued" to the diaphram , and I know you know that but that inventive inquisitive engineering brain of yours just has to ask anyway

Installed the new fuel shutoff, long story short, doesn't work.
The new solenoid is a little different than the old model. The old style diaphragm is in both the old and new solenoid, however in the new model it fits into another diaphragm that rides in a machined spacer. Not sure why, doesn't appear to allow more fuel space. Also on the new model the tapered thread of the emergency cutoff valve doesn't seat properly until the control arm is on the engine side of the solenoid, opposite where it's supposed to be on the old model. Too close to the engine to make it work.
Since the valve heads of both solenoids appear to be the same, I kitbashed the two solenoids. Assuming fuel is getting into the valve, nothing is leaking.
Installed it on Saturday, wasn't able to test it until today, largely because I'd left the power circuit on over the previous week and drained the battery bank down below the threshold where my smart charger would recognized the bank as a 24 volt system, one battery was drained to 1.4 volts. Had to charge all the batteries separately then rebuild the bank.
Next test will be continuity of the solenoid circuit, I suspect it's a grounding issue, the old model appeared to ground to the fuel pump??
if that fails I'll gut the solenoid and turn it into a manual shutoff.

I started the old girl up and let it idle a bit just because.

She likes her love.

Revived this M930A2. A rare truck for sure and worth the effort.

Auction listing states:
Doesn't start - false, dead batteries.
Doesn't run - false, bad fuel line.
Transmission doesn't engage - false, see above.
No keys - true!
Bonus: all the red wasps you can catch!

Multi-tested the fuel shutoff solenoid and I do have 24V going to it.
Taking it apart there was no sign of fuel in the manual shutoff valve while the diaphragm seat was wet with fuel indicating the pump's working but the solenoid isn't opening. Bench tested the solenoid and confirmed 24v but the magnet just barely holds the spring washer in place never mind crushing it flat.

What's the resistance in the solenoid windings? Is there a spec of what it should be?