DIY Injection Pump Reseal

Discussion in '6.9L IH & 7.3L IDI Diesels' started by jaluhn83, Jun 29, 2012.

  1. jaluhn83

    jaluhn83 Full Access Member

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    Anyone done any internal work on a DB2 pump? Yah yah, I know you really need special cal tools and bench and all, but it's doable if you're careful. I've got a welder with a Continental 3 cyl diesel running a BD2 and I need to pull the pump down, clean it and reseal it. I've done this with Bosch VE pumps on diesel and had good luck with them. The way to get around needing a cal bench is to just be extremely careful to note all the adjustments and then put them right back the same way. If the pump is in decent shape to begin with I think it's doable. But then I've never worked on a DB2. Wouldn't try it on the truck, but on the welder that probably woln't be used more than 10 hrs a year I can't justify $500 for a shop rebuild. The pump works but it has some rust under the top cover and leaks. I want to disassemble it, clean up everything and put it together with new seals, that should help.

    Thanks,
    ~John
     
  2. Black dawg

    Black dawg Registered User

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    where is it leaking from?
     
  3. Wyreth

    Wyreth Certifiable Noob

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  4. diezelcrazee

    diezelcrazee Full Access Member

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    It can be done. Bear with me this is long.....

    My 89 F250 farm truck started leaking fuel out of the IP drive shaft weep hole on the bottom of the pump. Leaking really don’t describe it, it had almost a steady stream running out of it. The old truck runs really well, and I hated the thought of putting a rebuilt pump on it which had all the adjustments set back to the stock settings. The way she smokes and runs, I’m pretty sure that this IP had at least had the fuel screw turned up some when the ole truck followed me home. :)

    I am a DIY kind of guy, and with a cheapo rebuilt IP starting at $350 or so, I really wanted to find out if there was a way that a I could replace the drive shaft seals myself. I figured it’s my pump and with a good manual I have been into some pretty detailed stuff before so why not. I figured if I mess this one up too bad, I do have another dead pump off my parts engine that I could use for a core if I had to go the rebuilt route.

    So I started reading about everything I could find on here and other forums, and what I found wasn’t’ very encouraging. Every body says you just don’t mess around with an IP, that there are to many adjustments and settings to get out of whack. Well, I’m just not a guy who can take no for an answer, so I kept digging the web for info, primarily for some kind of service manual on these pumps. I finally found out that there is a Navistar service manual on the 7.3 IDI with in depth directions on rebuilding the Stanadyne DB2. The manual part number is Navistar CTS 4245G, Volume 2

    I started searching the web and found an eBay seller offering volume 2 on a CD. (actually a 5 volume CD, the other volumes cover DT360, DT466 engines, etc) I bought the CD, opened volume 2 and found a PDF of an IH 7.3 IDI service manual with 423 pages! I haven’t even started looking at the engine rebuild, etc info. There is a whole section devoted to the DB2 with 26 pages on disassembly, 5 pages on inspection of parts, 28 pages on reassembly, and 13 pages on calibration. I noticed the eBay seller isn’t offering the CD right now, but I suppose they will as it was one of those multiple item type auctions. The whole CD cost less that $15 with shipping.

    Next step was to find a seal kit, and good ole eBay came through again. For $31.00 including shipping I got everything I needed here: http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&vxp=mtr&item=170855156259

    So with this CD manual on my trusty laptop, I went to the shop and built a rotating holding fixture which mounts on my workbench, and after mounting the IP, I went to work on it. I will be the first to tell you that there are in fact numerous settings that have to be calibrated for it to perform correctly, but my thought was that if I could mark/measure these accurately, I should be able to reinstall them in the same position. What I found was that to take her apart to the point that you can get to the driveshaft snap ring and pull the shaft out, there is really only 2 calibrations you have to concern yourself with. 1 is the position of the face cam (advance cam) on the throttle shaft. It is just simply clamped on the shaft and wherever you lock it down is where it is. There is no key, no spline, etc. So I just marked it lightly with a chisel to line up with the roll pin that is driven through the end of the shaft , and was able to put it back on exactly like it came off.

    The other calibration is the allen head guide stud which inserts into the mini-max governor rod assembly. It screws into front of the upper box shaped part of the pump housing on the fuel lines end, right above the little lock plate and screw that locks the transfer pump end cap in place. I just measured how far out of the housing the stud protruded with my caliper, and lightly chisel marked the top of it so that I could reinstall it back in the exact same spot it was before. The most important thing is to go slow and think/measure/mark anything that has some sort of calibration before you start messing with it.

    I finished my reassembly and I got the pump installed back on the truck. After cranking for a while, (these IDIs take some time to bleed the injectors), she finally coughed, and I bled it some more, hit the manual glow plug button for a few seconds and she fired up. I went for a short drive and it is running great, and NOT LEAKING ANYMORE!!!

    The outlook I have on all this is that if you are a person who can follow directions, take your time, and be fanatically clean and careful with precision parts, then you can take this manual and satisfactorily disassemble, inspect and reassemble a Stanadyne DB2 pump.

    They do call for a few special tools, like a seal expander to install the new drive shaft seals over the shaft, but I made it fine without them. I just took my time and was able to work the seals in place by hand without much trouble. The only “special” tool I used was a little wire hook I made to hold the fuel shutoff solenoid plunger back while installing the top cover. And, the manual showed me how it needed to be shaped. Other than that it was just an inch lb torque wrench, snap ring pliers and ordinary hand tools and allen wrenches.


    Hope this helps someone, and I hope I haven’t put anyone to sleep…..J
     
  5. CaptTom

    CaptTom Full Access Member

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    And the manual is awesome!

    THX again!
     
  6. BigDiesel

    BigDiesel Full Access Member

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    I have rebuilt 2 pumps so far with no special tools no calibration. Once you get the pump apart u will notice that it is very simple and is easy to take apart reassemble. The 99009 stanadyne manual has a different pump model pump parts wise. The cam ring pin is not threaded it just pulls out of the cam ring. The governor assembly is also different. Take note of the drive shafts rotation and the cam ring as the cam ring must go back in the same way as it came out. The cam ring has 2 different rotations one for the 6.2 and one for the 6.9/7.3. I just scribed a mark on the cam ring and the outside of the head as a reference point. I spent around 4-5 hrs start to finish on my pumps as they must be very clean when reassembled. I also used new diesel oil as calibrating fluid to lube, and coat all internal parts and orings. Good luck.
     
  7. jaluhn83

    jaluhn83 Full Access Member

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    Thanks all, glad to hear someone else is as crazy. I've had good luck with VE pumps when I did those, (VW/Volvo diesels) the problem with those pumps (had 2 different cars) was leaks and stuck parts from sitting 10+ years. Pulled them apart, put new seals in and it was good to go. Well, sort of. I think it took me 3 or 4 tries to get everything working right. They don't work so well with the transfer pump in backwards!
     
  8. NitroBlazer

    NitroBlazer Registered User

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    This is good to know! I've got a used pump I bought for my 7.3 with like 75k on it. I really want to try my hand at rebuilding my old one.
     
  9. mariner45

    mariner45 Full Access Member

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    I partially re-built a DBG rotary fuel pump - for a four cylinder engine. It is basically the same as the DB2 but with less cylinders (4cyl. v's 8cyl).
    My pump really only needed a few "O"ring shaft seals and a new set of vanes for the priming pump at the front. On my pump, the vane springs were shot on two vanes and the vanes themselves were worn. I too had to make a jig to hold the DB2 body with when using the bench vice.
    The pump now works very well on my old JD450 crawler loader. Like the original poster, I couldn't justify $650 on a machine I hardly use. No more fuel leaks either around shaft either.
     
  10. Black dawg

    Black dawg Registered User

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    If it was just a leaker, then this will work fine for you, but if it didnt work right you need to have a pretty good idea how these things work before you tear into it.
     
  11. jaluhn83

    jaluhn83 Full Access Member

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    Holy cow ancient thread! Never did actually tear into that pump - it's still on the to do list. LOL The pump in question is on a 3 cly diesel welder and it works fine but had gotten water in it at one point so I wanted to tear it down, clean and reseal everything. I also had issues with the clogging up the return valve on the top of the pump as well as it weeping fuel from somewhere. Still work though, so....

    I would be very hesitant to mess with a on road pump. Industrial engines are one thing, as they're going to be much less sensitive and generally lower rpm/power. A bit of a timing curve issue on a 1800 rpm 20hp engine is much less of an issue than on your turbo idi that's pushing much higher pressures and temps. It's also likely to be much more of problem if it dies on you.

    On the same topic, I did have pretty good luck overhauling the inline Simms pump on my old Ford tractor. The tractor had sat with the lines off and had rust on all 3 delivery valves, but with a bit of cleaning and messing around it cleaned up fine and runs real nicely now. Course, getting it there had me pulling my hair out for some days.... I got it as a non running parts case and did a complete motor rebuild, including the injection pump. I was very careful not to mess with the max fuel screw, thinking it would be in the proper place already.... well I get it bled out and I cannot for the life of me get her to fire. Seems to be pumping fuel, but no fire. Took the pump apart a few times, bench checked it, scratched my head, called some folks, scratched my head some more, and finally out of desperation tried turning up the fuel crew...bam! Starts right up! My best guess is when it first had problems (blown head gasket IIRC) somehow somebody adjusted the fuel screw all the way in.... and I never thought to check. Just goes to show....
     
  12. Agnem

    Agnem Using the Force! Staff Member Supporting Member

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    You can do it. It's what we call an "Amish rebuild", and yup there are fuel shops all around that do exactly this. You guys buy pumps from them and then put their names in the hall of shame. In my opinion, by the time a DB2 is leaking, there is a lot of other things "wrong" with it. You might "rebuild" it, but I promise you it will not run as well as it might of, nor for as long as, a properly rebuilt pump will.
     

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