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1945 TD9 Bosch Injection Pump rebuild


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Hello all,

    I decided to start a new thread with the teardown and rebuild of my Bosch injection pump.  My other thread about the pump was geared toward replacing it with an IH pump, but I haven't gone down that road, at least not yet.

    For those just joining the story, my TD9 was running fine on diesel but had NO power.  I couldn't even get it to go in 5th gear without stalling.  There was no smoke in the exhaust and the timing looked correct.  Just no power.  So I pulled the pump of a couple weeks ago and started tearing it down a few days ago.  I have the service manual that covers both the IH pumps and the Bosch pump. 

    As many of you already know, there is practically no shop around that will, or has, worked on these pumps and parts are hard to come by (understatement of the week).  I did talk to a shop in Philadelphia that could do and even has the proper test stand setup to calibrate it, but the price was astronomical.  So here I am doing it myself.  The Bosch pump does require a few special tools to get it apart which I'm fabricating as I go.  There don't seem to be a lot of proprietary seals that I won't be able to get from McMaster.

    Anyway, I have the pump about half apart.  I haven't found anything yet that would cause my low power issue other than the innards are FILTHY.  Looks like a lot of old crusty oil.  I was stressing that the cam was going to be wiped out when I removed it, but it actually looks really good.  There is a little pitting on two of the lobes, but not bad.  I measured the lobes and they all measured within a couple thousandths at 1.220".  Here is a picture of the cam.  The Bosch pump has roller followers and you can see on some of the edges of the lobes where the rollers didn't ride and there is no wear between the edge and the center.

     So far it doesn't look like any of the parts are unserviceable.  The harder part is going to be building a test bench so I can set it up properly.  I'll post more as I go.

 

20210822_183830[1].jpg

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I have fuel pumps on both my TD-14 & -14A crawlers rebuilt by Central Fuel Injection in Estherville, IA.  They have worked fine for several years.

Vic 

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I thought I had talked to them already but I guess I didn't.  Anyway, just got off the phone with them and they no longer do anything with the Bosch pumps.  So, I am back to the original plan.  If I can successfully get a test bench up and running I'm sure it would be a huge help to the folks here.

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i sure am curious where you will find parts for this pump. pretty much the same as the bosh PSB pumps on the old case. obsolete. it would be easier to install the ihc pump. ih only used these pumps for a very short time.

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Well,  I haven't found anything wrong with my pump yet, but the search continues.  Maybe it just needs a good cleaning and calibration.  Whichever direction I go it is going to cost me.  Even if I got an IH pump it would still need to be calibrated on a stand so I figure I'm not wasting my time building one.

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4 hours ago, WaldoTD9 said:

Even if I got an IH pump it would still need to be calibrated on a stand so I figure I'm not wasting my time building one.

why?  show the "calibration" procedures and What if anything you can do today to change output.

when !!  RM parts were available after I spent $2K 1990 for an intentional disaster rebuild, had  2 done at a "proper" shop...  $200 and 45 minutes.

every part was checked  passed/' or changed. tech said my work is guaranteed if you want to wait 2 days for a slot and pay $250 more  there is a slight chance "calibration" will find a 2 % difference

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On 8/23/2021 at 4:36 PM, WaldoTD9 said:

Well,  I haven't found anything wrong with my pump yet, but the search continues.  Maybe it just needs a good cleaning and calibration.  Whichever direction I go it is going to cost me.  Even if I got an IH pump it would still need to be calibrated on a stand so I figure I'm not wasting my time building one.

Go for it MDiesel I think self taught all this stuff, if you have the interest and means, did you try @Injpumped

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No.  I guess I should have asked if anyone else on here had their own test stand that was willing to set up my Bosch pump or knew anyone that did.  Every place I have called that is supposed to be able to help with these pumps has stopped doing it.  Maybe they still do the IH pumps, I don't know. One place I talked to said it would cost a few hundred dollars just to get the adaptor to hook up a different pump to his machine.

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I have the Bosch APE 4A-800 (or 80Q ?) injection pump on my TD9, too.  It runs fine. But I have one bad injector and I thought I could swap out another injector from another motor that has an IH pump.  Top injector in photo is the Bosch. (does it look like yours?) Bottom is the IH. Different animals.  Not sure if I can offer you any good advice, WaldoTD9, as for bench testing a Bosch but from what I am learning, to convert to an IH pump you need lines and different injectors, for what it's worth. (I have the IH parts but going to see this week if any diesel shops can repair/replace my one injector. If not then I guess it's a complete changeover. )

20210828_160230.jpg

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bcf180,

     Mine is the top one.  The fitting threads for the fuel line on mine are 5/8-18.  What is wrong with your injector?  I've disassembled most of mine and there is not much to them to go bad.

     As for my injection pump, it should be good to go once I put it back together and set it up.  It was pretty dirty on the inside and I could tell when I pulled it apart that the plungers were not all set the same.  I have the materials to build my test bench and injection lines.  I also bought a pop tester to set up my injectors.  I just need to make the lines.

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Good job, nothing like diving in and doing it yourself. Getting hands on knowledge is always good. Pics are always appreciated, and I'm sure down the road this write up will help someone get the courage to fix their own equipment as you are. 

 

Mark

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23 hours ago, WaldoTD9 said:

What is wrong with your injector?

Not sure. Maybe some air pressure to blow the junk out of it, is all that it needs.  My diesel guy got back to me today and said that he could service it but parts are expensive. 

Does the top part of the injector just pull out of the nozzle body or is it threaded in?

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The top is threaded into the body.  You can disassemble it yourself no problem and clean it.  The problem is you can't test it without a pop tester.

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  • 2 weeks later...

I was finally able to get my injectors back together in a manner that they opened at the proper pressure and were within specs on holding pressure and leakage.  Just in case anyone else plans on rebuilding their injectors, it isn't hard, but it is tedious and it may take MANY tries to get the valve to seal. At first I tried lapping the valve and seat together and that would not work even though I had very very fine lapping paste.  After doing some research on valve lapping (most of the information is on car engine valves) I discovered that you can't get the valve to seal by lapping it. So I had to "regrind" the valve and seat by using very fine sandpaper (400-1500).  I put the valve stem in my lathe, spun it at 300 rpm, wrapped the sandpaper around a 1-2-3 block, and held it against the valve sealing surface. Then I did the same thing on the valve seat but used a deburring tool to get the proper angle on the seat.  The seat was easy, the valve was more difficult to get nice and flat.  They are pretty small.  I ground the valve till I got a nice consistent contact ring indicated by putting layout dye on the valve and spinning it lightly against the seat.  I did all four valves this way.

Now I am in the process of reassembling my pump which I will test before it goes back on the tractor. 

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I got my pump all back together, which was not that difficult.  I made all new paper gaskets out of the readily available FelPro rubberized gasket material available at most auto part stores and online.  The one lip seal for the camshaft seal was easy to source from McMaster.

The biggest unknown was, would it work.  It actually didn't take me that long to put together a test bench.  I was going to pull the motor off my Craftsman table saw so I wouldn't have to buy a new motor just for this single use, but then a friend of mine suggested I just leave it in place and use the table saw table to mount everything to.  Genius.  All I had to do was get the 3500 RPM table saw motor down to the 550 RPM to drive the pump called for in the manual.  Luckily, I was able to do this with two pulley reductions.  Again, I just ordered four new V-belt pulleys from McMaster to step it down.  I went 1.5" to 4" (motor to blade arbor) and 1.5" to 4.5" (blade arbor to pump). I should have used two 4.5" pulleys because my final pump speed was about 650 RPM under load.  I was able to get that down to ~550 by raising the blade arbor so the belt would loosen and slip a little.  It worked great.

I ran the pump at the original settings it had when I pulled it off the tractor and saw why I was having power issues right away.  I was getting less than half the fuel delivered I was supposed to.  I adjusted the plungers (a lot) and got them all to consistently deliver the 48 ml required.  I ran the test four times to be certain I got it right.  Now I can't wait to get the pump and injectors back on the tractor to see how it will run now.

Here is a picture of my setup.  I also took a bunch of video I will compile and post to YouTube if anyone wants to attempt this themselves.  The hardest part was actually making all the fittings and lines.  Since the pump and injectors use nonstandard fittings I had to make them all from scratch on my lathe.  They turned out well, it just took some time.  I didn't spend more than a couple hundred dollars to do this whole job (rebuild injectors, rebuild pump, construct test bench).  

20210918_142622[1].jpg

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Obviously we get presented with a lot of questions without knowing people’s skills, fortitude and abilities. Congrats and thank you for your contributions!!

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