Ready to "open up" my 350 injector pump.

[Larry 8N75381]

Anyone have any "DOs/DON'Ts or suggestions to offer before I start. Besides 'Don't do it!!" with the same emphasis as the "husband" in Ray Stevens song "The Streak". For anyone not that does not know of the song, here is the YouTube version of it, enjoy. http://www.youtube.com/watch?v=85krLPrWWTY

I DO have, thanks Lavoy, the service manual for the John Deere injector pumps. All I need to do is replace the governor weight retainer and the weight retaining ring that is plastic fiber. I have the all steel replacement. Fuzz from the plastic has been plugging up the fuel return check valve which kills the engine. Engine runs fine when valve is clear, so don't think I have any other problems with the pump.

Larry

[jdemaris]

Anyone have any "DOs/DON'Ts or suggestions to offer before I start.

There are a few common mistakes people often make, when it's the first time. I base that on what I saw, when I was training people how to do it.
Obvioulsy, not everybody makes the same mistakes.

You might read that book carefully and be fine. Me? I tend to charge into things with only quickly skimming through directions. I read them in full detail only when I get into trouble. So, I often learn the hard way.

#1 You need the special fluted wrench to get it apart. Do you have it? It's the six-tooth Bristol wrench to get the head screw out. I don't know any work-around, you really need it.

#2 If you have a digital camera, take photos along the way of the governor, linkage, etc. It might help you later if you're not sure about proper assembly.

When you use that special wrench, if that head screw feels like it doesn't want to turn, do NOT force it. It can, and will break off. If stubborn, with the wrench in it, give it a good rap with a hammer to shock it while trying to turn.

Make sure that the brass bushing at the end of the pump, where the driveshaft and seals ride, does not have a wear-gouge in it. If it does, replace it. A new one only costs about $7.

When putting the governor together. Put the weights in first, with the cage facing up. Then spiral in the steel thrust washer and make sure it's located in the groove in all the weight. Then do the same with the thrust-bushing. Then, with the assembly kept facing up so it does't fall apart, install the pump housing down over it. Before you do, put some banjo bolts into the head, in the discharge ports just as they would be when the injector lines are installed. They will act as stops and prevent you from pushing on that housing too far and cutting the big o-ring.

Once you have that aluminum housing installed, BEFORE you lay the pump down, get the throttle linkage and shaft installed and tie it back to full throttle position. By doing this, spring tension holds the governor weights in place. You need to keep it this way until you install the pump and the driveshaft is there to hold it all together.

When assembling all parts, I use a mix of half diesel and half motor oil. Always worked fine. Once all together, you can use a hand held squirt oil can with the nozzle of it stuck into the fuel inlet fitting. Just keep pumping while you slowly turn the pump with a large screwdriver. As long as the pump is turned on, it will prime itself, even at that low speed without an air-tight fuel connection. It will first turn easy, and then turn hard when it starts to pick up prime. Then it will click and shoot fuel from the discharge ports.

[Larry 8N75381]

Thanks jdemaris,

I have been studying the manual off and on. Each time I think I gain a better understanding. But I wish that some of the pictures were better and that there were more. One problem is that there are several variations of things, yet no picture or only one. But that is not to uncommon for manuals.

I was familiar with Bristol set screws from working at Collins Radio in the 1950's. And I have several Bristol "L" wrenches in amongst all my Allen wrenches. So I was not "put off" by the "you need a Bristol wrench" comment. BUT, I thought I should look at the cam advance pin just so I could check and see if I had the right size. So the first thing I opened up was the advance screw hole plug. WOW! The Bristol socket in the pin is a BIG honker!! I was used to small Bristols even had worked with the 4 fluted ones but nothing bigger than something like in a #10 set screw.

Now I am looking for the wrench you mentioned. Do you have one to sell? OR can you give me the name of a supplier? Biggest issue would be to get the correct size as there are several that are close - did a bunch of web searching and ended up at the Bristol Wrench Company web site. They list the sizes, starting at the largest, as .595, .454, .372, .291, & .251 for the largest five. Size is the major diameter of the wrench. My guess is that the .291 is the right size, but can't be sure - no easy way to measure it.

You said "I don't know any work-around, you really need it." and I really believe you! I could see some guy trying a regular allen wrench in there but then buggering up the Bristol splines. At which point you have a real mess! Extracting buggered up/broken bolts/screws is nothing short of really NASTY!!

I do have a digital camera and will take pictures as I go. I have pulled apart a lot of things and usually managed to get them back together, even if it took several tries. The ones that were "fun" were the ones that "flew apart" as you pulled them apart not knowing that there were springs in them. Most of the time there was NO one to ask, so I GREATLY appreciate your helpful comments.

Regards,
Larry

[jdemaris]

Thanks jdemaris,

Now I am looking for the wrench you mentioned. Do you have one to sell? OR can you give me the name of a supplier?

Stanadyne part # is 15499 for that wrench.

There is a place selling off many Stanadyne tools cheap at 1/2 price to anyone. They had a bunch for sale, but my son and I may have bougth the last ones? If so, he's probably sell you his for what he paid. Ended up, he didn't need it. His pump is a later model, and doesn't use that head screw anymore. I think it cost him $4 plus shipping.

Funny thing is, that six-toothed head screw wasn't used on several other tractors either. The Roosa Master pump on a Ford diesel uses a standard Allen head screw instead. I've only found this Bristol screw on Deere and a few IH tractors.

I just checked, and they show out-of-stock with the number I gave you, but say they have an alternative for $6.14. New number of 24992 and they only have one left.

http://www.thompsondiesel.com/Stanadyne.htm

[Larry 8N75381]

Sent you a PM, jdemaris.