1971 M818 Tractor T-Handle pulled while running. Cummins straight six.

818 Test Pilot · Sep 11, 2019

at a show someone started my rig and stopped it with the emergency shut off t-handle. have pushed in handle and placed the under hood shut off valve arm in the 6 o'clock position which I think is correct. and yes steering wheel was chained. I am a former helicopter mechanic and mechanically inclined. My M818 has started on first try year round for the last 5 years. I need to know how to get this trusty M818 started. tried to prime. the Allen wrench plug on top of pump stripped out. removed small Allen wrench plug next to it and and did get about half a beer glass of fuel in the pump. no start. tanks are full with new JP/8. runs till ether can depletes. thinking of dropping a Pratt & Whiskey 4800 SHP in my rig to solve the problem.

simp5782 · Sep 11, 2019

818 Test Pilot said:
at a show someone started my rig and stopped it with the emergency shut off t-handle. have pushed in handle and placed the under hood shut off valve arm in the 6 o'clock position which I think is correct. and yes steering wheel was chained. I am a former helicopter mechanic and mechanically inclined. My M818 has started on first try year round for the last 5 years. I need to know how to get this trusty M818 started. tried to prime. the Allen wrench plug on top of pump stripped out. removed small Allen wrench plug next to it and and did get about half a beer glass of fuel in the pump. no start. tanks are full with new JP/8. runs till ether can depletes. thinking of dropping a Pratt & Whiskey 4800 SHP in my rig to solve the problem.

The ball valve is stuck closed. It happens. Or the handle arm isnt moving the rod on the valve itself. Known to happen. Its a pricey cummins part # 208087. You can take the metal line off and try to pry it open or remove the arm and twist the little nipple with some pliers to open it if the arm is moving and the nipple is not.

https://youtu.be/ciHolYwAXNQ

98G · Sep 11, 2019

Under hood arm goes counterclockwise. Towards the front of the truck.

818 Test Pilot · Sep 11, 2019

simp5782 said:
The ball valve is stuck closed. It happens. Or the handle arm isnt moving the rod on the valve itself. Known to happen. Its a pricey cummins part # 208087. You can take the metal line off and try to pry it open or remove the arm and twist the little nipple with some pliers to open it if the arm is moving and the nipple is not.

https://youtu.be/ciHolYwAXNQ

first thing tomorrow gonna ck this.

818 Test Pilot · Sep 18, 2019

M818 Cummins starts with either.

While running an Army person pulled the emergency shut off T-handle to shut off my M818 a week ago. Since then, doesn't fire off. #1 pix is the knurled knob. Its all the way unscrewed. #2 removed this shut-off and made sure it works properly. Forward is open. #3 what is this device and when and what activates it to work. *** primed lines/frame mounted fuel filter is full/using right tank/pump
big 12 o'clock prime
plug Alan wrench detent is stripped/ removed pump 12 0'clock
small Alan wrench plug. doesn't really accept fuel/cracked some upper feed and return lines and fuel leaks/tightened up everything/would not crank over at all like all cylinders wanted to fire?/ todays a new day and again only runs on either.

Ajax MD · Sep 19, 2019

I'm new to ownership and in-depth maintenance on these trucks but since no one is responding, I'll take a stab at it.

You say "not accepting fuel" and say that it does run on ether. It sounds like the guts of the emergency shutdown are jammed up and not opening when you reset the manual linkage arm.
I recommend that you stop using the ether on the engine now that you've proven that the engine will run. Ether isn't great for the long term health of the NHC 250.

As Simp said above:

The ball valve is stuck closed. It happens. Or the handle arm isnt moving the rod on the valve itself. Known to happen. Its a pricey cummins part # 208087.

I think you might be at the point where you need to buy this part.

simp5782 · Sep 19, 2019

818 Test Pilot said:
View attachment 776740 View attachment 776741 View attachment 776742 While running an Army person pulled the emergency shut off T-handle to shut off my M818 a week ago. Since then, doesn't fire off. #1 pix is the knurled knob. Its all the way unscrewed. #2 removed this shut-off and made sure it works properly. Forward is open. #3 what is this device and when and what activates it to work. *** primed lines/frame mounted fuel filter is full/using right tank/pump
big 12 o'clock prime
plug Alan wrench detent is stripped/ removed pump 12 0'clock
small Alan wrench plug. doesn't really accept fuel/cracked some upper feed and return lines and fuel leaks/tightened up everything/would not crank over at all like all cylinders wanted to fire?/ todays a new day and again only runs on either.

#3 Is the fuel shut off solenoid. Your ignition switch delivers it power. You should have 24v with the main switch on. You can simply bypass it and screw in the thumb screw on the front of it and see if it will fire off.

If you pulled the manual shut off valve off the truck did you spin the motor to see if you had anything coming out of the fuel shut off valve

JJP · Sep 19, 2019

I had something similar happen to me with a 900 series wrecker. It was new to me and seemed to run fine for a couple months. Shut it down and it wouldn't start. We played around with the pump and supply end of it for quite sometime before looking further down the line to find it was plugged screens on the injectors. just happened to be a coincidence it wouldn't start after but ran before. With that I learned that the pump with that line off the shutoff and the shutoff open doesn't put out much fuel. Just a fountain of about and inch or maybe two will tell you if it is open.

We pulled one injector, cleaned the screen which was plugged with a reddish brown colored goo and it started. We then went through them all and found the same junk. Ended up pulling the tank and cleaning the crud out of the bottom which looked to be the same as the stuff clogging the screens. The pump had the same stuff in it.

Hopefully yours is just the shutoff.

doghead · Sep 19, 2019

I don't see the shutoff cable in any of the pictures.

818 Test Pilot · Sep 19, 2019

yup took the valve off and it works correctly. with arm forward the inside orifice is open and to the rear its closed. simp5782 sent the link info. and yes for the heck of it ckd around my key local parts people. 204 - 240 clams but the valve is ok knock on wood. yea ether aint good but all my years as an 88M used it bunches. Now that I have to use some of retirement funds my thinking kind of is different. Thanks for reply Ajax.

818 Test Pilot · Sep 19, 2019

This is the second time in a bunch of years someone pulled the this T-Handle and pushed it back in with out me knowing it. To have ol betsy not fire up right away gave me a look pf disappointment. Yea back to picture yes didn't reconnect yet. Its tucked up outta the pix.

818 Test Pilot · Sep 19, 2019

Ajax MD said:
I'm new to ownership and in-depth maintenance on these trucks but since no one is responding, I'll take a stab at it.

You say "not accepting fuel" and say that it does run on ether. It sounds like the guts of the emergency shutdown are jammed up and not opening when you reset the manual linkage arm.
I recommend that you stop using the ether on the engine now that you've proven that the engine will run. Ether isn't great for the long term health of the NHC 250.

As Simp said above:

I think you might be at the point where you need to buy this part.

removed valve and ckd out. Good to go.

818 Test Pilot · Sep 19, 2019

98G said:
Under hood arm goes counterclockwise. Towards the front of the truck.

to the front. 10/4.

818 Test Pilot · Sep 19, 2019

simp5782 said:
#3 Is the fuel shut off solenoid. Your ignition switch delivers it power. You should have 24v with the main switch on. You can simply bypass it and screw in the thumb screw on the front of it and see if it will fire off.

If you pulled the manual shut off valve off the truck did you spin the motor to see if you had anything coming out of the fuel shut off valve

Roger That.

818 Test Pilot · Sep 19, 2019

simp5782 said:
#3 Is the fuel shut off solenoid. Your ignition switch delivers it power. You should have 24v with the main switch on. You can simply bypass it and screw in the thumb screw on the front of it and see if it will fire off.

If you pulled the manual shut off valve off the truck did you spin the motor to see if you had anything coming out of the fuel shut off valve

Used a volt meter to ck for 24 VDC at wire connection to device with batt rocker switch on. Zero. Screwed in knurled knob to open valve. Still no fire up. Gonna get to know system one way or another. I will disco top side line and crank to see if any fuel pours out in the a.m. No voltage is another issue so the knurled knob is staying in for now.

818 Test Pilot · Sep 20, 2019

We

JJP said:
I had something similar happen to me with a 900 series wrecker. It was new to me and seemed to run fine for a couple months. Shut it down and it wouldn't start. We played around with the pump and supply end of it for quite sometime before looking further down the line to find it was plugged screens on the injectors. just happened to be a coincidence it wouldn't start after but ran before. With that I learned that the pump with that line off the shutoff and the shutoff open doesn't put out much fuel. Just a fountain of about and inch or maybe two will tell you if it is open.

We pulled one injector, cleaned the screen which was plugged with a reddish brown colored goo and it started. We then went through them all and found the same junk. Ended up pulling the tank and cleaning the crud out of the bottom which looked to be the same as the stuff clogging the screens. The pump had the same stuff in it.

Hopefully yours is just the shutoff.

Well guess watt? Went out today and disco’d output of shut off valve. Turned over and saw a little fountain. Connected back up. Screwed in knurled bypass screw. Turned over started in 5 seconds. Let run. Went to shut down operation. No dice. My guess by passing electric shut off o well. Put in high gear wid foot on brake let out clutch. Screwed back out and fired up. FYI- Bypassing electric shut off disables usual shut down operation. Had to celebrate. Went to legion.

Ajax MD · Sep 21, 2019

Congrats. So you'll replace the electric shutoff?

818 Test Pilot · Sep 21, 2019

Ajax MD said:
Congrats. So you'll replace the electric shutoff?

Knot going to say yes or know until a couple test flights. And.... Removed the instrument panel and disco’d rpm cable. Found out why it doesn’t indicate. Internal End of cable shaft broke at spinning part of gauge. I like when stuff gets broke sometimes here @ conus. Had a different opinion 7200 miles west of here when desert touring.

818 Test Pilot · Oct 6, 2019

my M818 Is running perfect. and now know how the motor and how and what is needed for lite off. On to the next fun. My M818 Desert 5 ton Tractor will be there. Touch A Truck Day at the New England Air Museum is 12 OCT 2019.

1971 M818 Tractor T-Handle pulled while running. Cummins straight six.

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