NHC-250 injection pump woes - PT pump in ruins

[OPCOM]

Most of this has been resolved. The only outstanding issue is the un-approved labor overcharge of $1000. That should be cleared up soon.

As for the pump cost which is admittedly double what it should have been, the shop they use for pumps does good work as evidenced by the way the truck runs but has overcharged them on this and won't budge claiming many hours spent figuring out the settings "because it is a military unit and there are no settings available". I called BS on this because it is also a "stock NHC-250 with stock NHC-250 ratings and performance". So I know better than to have that pump shop used again. I am not interested in paying for learning curves. The thing is not the space shuttle after all.

I replaced the starter today. The motor section was OK but was drawing about 200A instead of 120A under no-load so it was somewhat worn. It did not "need" to be replaced and would probably have lasted me a couple years at least. Due to it being a PITA to replace, I decided to do the entire unit rather than just the bendix contacts.

I also got the spare fixed.

It cost me far less to do it myself than to have let the diesel shop do it when they called and said it was bad. Both for the part and the labor. I do a lot of work myself and hate taking things to repair facilities for obvious reasons. I will only take things in for something large or confusing.

I am going to try mashing the tach cable a little to get it to bite properly.
But how do I do this? It seems like it is not easy to just mash a steel shaft ??

 

[doghead]

I would start with a large set of Vise Grips. Tighten and clamp, then re-tighten and clamp again... repeat if it is working, until you get the desired "mash".

If that doesn't work, a hammer and block, and gently tap it repeatedly until you get the desired "mash".

From the description of your problem, I would think you will want to "squeeze/mash" it on the sides 90 degrees from the drive tang.

I would stop deforming it as soon as it seems to engage(drive).

 

[WillWagner]

There is a little aluminum tag on the pump that gives everything needed to rebuild that or any other PT pump to the spec for your engine. OPCOM, they are blowing smoke.

 

[Hammer]

Doghead got it, squeeze/smash with vise grips. Works really easy actually!
Just do it in SMALL amounts, and run it even down the sides, then start the next level. You don't want it kinked or breaking on you.
Took me just a minute or two to do the whole thing (once I got my brain wrapped around WHY it wasn't engaging properly!)

 

[Hammer]

Oh yeah, you are not really trying to push the flat spot out further, but to make the shaft itself oblong so that it pushes against the opposite side of the shaft from the flat spot. Making the opposite side more oblong like that will push the flat spot into the groove just fine, and keep you from messing up what needs to be pretty straight to fit into the groove on the IP drive part.

 

[OPCOM]

I have been sort of busy the last couple weeks, with starting to put up a 50FT ham radio tower (meaning digging a hole 5 FT deep and 30" square..) and worst of all my beloved old cat passed away last week, so I have not done much here. I'm glad Abby lived so long, 17 years. A good cat, like a little child to this old single curmudgeon, it took the wind from my sails. - but life has to go on and I am going to try the mashing of the cable soon, and take pics to report.

Now, as to the shop, I have finally gotten everything straightened out. All I can say is there was a heck of a lot of mistakes made and a lot of time spent on stuff that should not have needed so much time, and some of it was at the pump rebuilders too, but at least the pump is running perfect and the job was done right. Later I am going to do some calling around and see where the older shops are with the old guys that are used to working on the NHC250. The only reason I usually pay anyone to work on the truck is because I have some physical problems. I do as much as I can though as the old build of my previous M35A2 commo truck would reflect. This time, I needed pro help because the IP had to be diagnosed. I can say one thing, all this has made me read and re-read the books on that truck. So, problems solved. Carry on!!

 

[alphadeltaromeo]

Patrick - sorry for all the problems. If you were driving by, I'd have helped you again!

At any rate, where are the links to your new 818 with the shop body on it...have you done much to it? I've been outa the loop, so post up a link or PM me with a link to the pics.

Glad you're back on the road with the truck though

 

[alphadeltaromeo]

Bummer

Patrick - sorry for all the problems. If you were driving by, I'd have helped you again!

At any rate, where are the links to your new 818 with the shop body on it...have you done much to it? I've been outa the loop, so post up a link or PM me with a link to the pics.

Glad you're back on the road with the truck though

 

[Rene M]

There is a little aluminum tag on the pump that gives everything needed to rebuild that or any other PT pump to the spec for your engine. OPCOM, they are blowing smoke.

YES, its called a CPL fuel code and it tell"s you every thing! Idle speed, max fuel settings, max rpm, hp, torque etc...
I still have your cable and was in your town last weekend getting hammered by the storm carrying 7 hemmit rims and 7 tires.. My power inverter went out, i did not have your # ... lets just say it was a bad weekend.. I can ship it to you though?

I will pm you my # and when you get a diesel question give me a ring im 5 hours away and have a shop " with connections in Dallas"

 

[OPCOM]

Thanks Rene M. Pm me and i'll connect with thanks.

I have not done much on the truck yet, it got hot here, and the project of putting up a 60FT ham radio tower has taken precedence.

I have a large size AM transmitter and I am waiting for a chance to get that monster on the air. This is the typical mad scientist sort of giant radio transmitter with many switches, meters, and dials. It was home made by COL Tucker (R.I.P.) of the Texas State Guard in 1956. It took him 2 years to build it. I owe it to the transmitter, the Guard, and the old COL. to restore it.

I am currently rebuilding the RF deck's grid drive section. Also need to move the plate choke closer to the plate, as it is a huge 7 nanoseonds away from the anode via a copper strap, creating a high-Q parasitic line within the tubes' power bandwidth , and build a new low voltage supply for biasing the new modulator.

Then it ought to be OK. I do technoid stuff in the summer here. I do not like the heat in Dallas in the summer. The point is that electronics isn't boring. It can be an exciting adventure if yur doin it right. The cabinet there is 30" wide, not the usual 19"one, so this is really fun to get back to.