I got my 120,000 mile pump in the foreground and another $40 shipped off ebay pump in the background for practice and parts. Anyways here is the pump rebuilding shop I got set up to "re seal" this 120,000 mile pump. I have found very minor spalling on the cam but I am going to put it back in. I don't know whats acceptable and whats not. I don't know whats going to last for 10,000 miles or what will last another 100,000 miles. So I am just going to stick it back in there. For what it's worth the $40 pump does not have spalling at all on the cam lobes but it looks more worn down so I am not sure what is better to use. I am sticking with the original. I am curious to see what the current pump in my truck looks like. You can bet that thing is getting dissected. Anyways I have run into a hiccup and am hoping somebody can help I have 2 of the springs mixed up. They look almost identical. See the picture below.

Can anybody show me a picture of the difference between these 2 springs I think one has like 14 coils and the other has about 16 coils they are both basically the same diameter but the "spring rate" is going to be different and crucial hopefully somebody can tell me the difference. Thanks in advance.

 

I don't know. FWIW, When I did mine, I did not take the governor linkage apart due to concern of not putting it back at the same spot. It looked ok, so i just cleaned it really well. If it is really important you can always order them and put them in the correct location.
If the spring placement confusion is on the experimental cadaver don't worry about it. If the confusion is on the ip you plan to use, you might as well get a newly rebuilt unit as it is not likely you will be able to correctly readjust the pressure without the right equipment.

 

Since you have the manual/diagram order one of the springs but not the other. Should be really cheap and then you'll know which is which.

If I had to take a guess it would be that the governor spring is the longer of the two. Maybe you could disassemble your eBay pumps governor droop rod and compare?

What is this cam you speak of? Is it the main shaft? Because there are updated seals for the main shaft and I can get you the part numbers as I have the service bulletin for it somewhere. That should fix any chance of it dumping diesel in your crank case

 

I can't really see on the Pic, but I think one spring is the advance plunger spring, and the other is the gov base idle spring.

You can adjust the base idle nut without any specific equipment, but have to make incidental adjustments with top cover coming off, did a write up a few weeks ago on setting that one.

Though I have yet to tear one down and repair, so I am no expert. Just figured out how to adjust and tune one.

Probably be just fine reusing most parts and springs, just replace if you see obvious damage somewhere, I think the advance piston should get fresh rings, I think it was recommended. Reseal it and hope for the best.

Be sure to scribe or punch marks on every fastener, and count/write as you go thread count.

Also there may be something of an almost Allen head bolt on the underside, that is some speacialty bit, and an in between, some said Allen works if you are very careful, but if wrong can break or strip, if i can remember what they said it was I will reply.

Please tell if you run into any challenges and how it all works out. Also, they used these pumps on many different applications, and some heavy equipment operators seem to have much experience in rebuilds, may ask around on one or another of their forums for advice.
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Bristol - I think they call it a Bristol type fastener, check with stanadyne dealer to see if that's right or I'm just imagining it.

Also, check your injectors, I had one partially sticking open, and caused a compound fueling problem. One, a slight line in restriction. Two, one injector staying partially open, at high speeds inducing high pressure cylinder gas feedback. Pushing against the fuel backwards, and causing weird problems. One problem would run funny.. 2 or several issues cause cascading problems and confusion. Good luck, later

 

This is the Cam I speak of. See the top of those lobes have whats called spalling as I understand it. Not sure how long it will last. I might take a picture of the ebay pump cam it DOES NOT have any spalling that I recall.

As for comparing springs on the ebay pump the governor spring was missing......... So the one that is in it might be the original governor spring or the spring that is supposed to be where it really is supposed to be. I think it's the transfer pump regulator spring. Anyways the ebay pump has all sorts of missing washers and **** on the main shaft so whoever was into that one last messed it up and lost some parts. I can see why though after tearing into these things they are intimidating. I made sure I kept everything in one of those black organizer trays.

 

I did not run into the Bristol type fastener? I have watched a youtube video where they talked about it? I don't know.

 

Oh okay, Good to know, I guess these can be worked on with regular hand tools then.

It was just mentioned as something to be careful about when I was reading about the pump on a forum, but some said different things about it so I don't really know, just internet conjecture I hadn't myself taken one apart.

I'd like to rebuild my old pump though, it ran great for many years, and isn't so bad.. I'm sure a gasket kit and replacing small worn pieces if they present themselves would get her right. So I'm looking forward to seeing your project here.

 

ya interesting stuff here, i always use junkyard pumps with success.

 

I read it wrong at first but this should help determine if your cam is worn.

 

Thanks DarkOverCast I have not seen that literature yet. I got to thinking that all of that metal that has come off the cam in the form of spalling/flaking would probably end up in the injectors right? Clogging them and causing them to drip and what not? Anyways taking some time today to put it back together following the manual.

 

That picture was out of a standadyne db2 model manual I found off there website iirc. It's amazing all the things you can find in pdf online. I like to print them out and have a hard copy.

 

http://www.stanadyne.com/dealerportal/ssi/Navistar/04826.pdf

Some injection pump specs should be close enough to an 89 with a manual. If anybody has a closer match please post here.

 

I have decided to use the Ebay pump cam. It actually looks a lot better than the cam I got from my $80 craigslist pump.

 

Using some little Brad nails here to "shim" out the shoes on the rollers to get my roller to roller measurement which determines maximum fuel flow as I understand it. This is a pretty crucial measurement so I tried my best here to get it as close to what I believe to be on the money as I can get. 1.970 inches roller to roller. (7.3, NA, Manual ,3500 ft elevation) For what it's worth I tested to see how big of a difference it made to turn the fuel up 1 flat (backing off the leafspring by 1 flat yeilded a roller to roller measurement of 1.977 which I was pretty sure was too high based off of all the references I have been reading. Although a lot of guys out there are turning their pumps up by more than 1 flat. Sometimes 2 or more god knows what they are running for roller to roller clearances. I did the same thing the other way (starting back at my 1.970 starting point) I turned the leaf spring in by one flat and it yeilded a roller to roller clearance of 1.962 inches. That sounded pretty anemic so I just stuck with the 1.970. I gotta start somewhere.