Rebuilding the Injection pump

[Floridianson]

My problem now is I know what I want to say, but what comes out isn't always what I wanted to say.
Before I forget, do you have any Injection pump "operating shafts" laying around ?

Yea stick me with a fork because I think I am done as nothing I say or do is coming out right.
I have a IP that is some what stripped and can send it to you. PM me you name rank and address.

 

[rustystud]

Could you post a pic? Not sure which part that is.

This is the shaft that the control rod connects to. Out of the three pumps, two had this shaft bent really bad as seen here. If you have the whole small housing that the shaft fits into that would be even better.
Thanks Chris.

 

[rustystud]

Yea that little 82 toyota is not living the easiest life with me haha.

The flu sucks to deal with, all 3 of yall sick together would make it very rough.

If you still want/need injection pump parts in March let me know. The LDT from my old m35a2 is destined for scrap and still has the pump attached to it minus the hydraulic head.

That would be real helpful Red ! I can always get Hydraulic Heads. For some reason they are quite plentiful compared to the rest of the parts, and actually quite easy to refurbish. Try finding a good condition "Cam" and "Roller Tappet" for the pump though !

 

[rustystud]

Since the oil fitting under the pump bodies seems to get damaged a lot I decided to find my own. Since I came up empty handed with all my fitting sources I decided to make my own. I bought a few "tall 90 degree" 1/8" NPT by 4AN fittings and a 1/16" NPT x 4AN straight fitting. After drilling the 90 degree fitting for the 1/16" NPT fitting I tapped it out in three stages. Since there is limited space for the standard tap, I ran the first one down until it bottomed. Then using a 1/16" tap with 1/4" cut off the bottom, I ran this one down until it bottomed. Then using the third tap with 1/2" cut-off I ran this one down until it bottomed. The straight 4AN fitting I had to cut off 1/4" off the threads. Then using "Loctite" I installed it. The last thing I had to do was drill out the fitting where it blocked the openings in the 90 degree fitting. In the last picture you can see the drill marks on the fitting.

 

[rustystud]

I had planned on submitting all my pictures at once of my Injection Pump rebuild, but since it is taking so long due to my being sick for one and having to have made-up a "cam" bearing installation socket I decided I would start now. The first thing I rebuilt after spending weeks cleaning up these 7 pumps was the "booster pumps".
Since a lot of guys end up replacing the seals in these I thought I would just share my rebuild now.






In picture one I just finished installing the shaft and gears. I used "engine assembly lube" from Summit racing, so if you see some red looking stuff on the gears that is it, not the gasket maker. Picture two shows me cleaning the surface with "lacquer thinner" . Picture three shows me installing "Loctite 515" gasket maker. Be very careful doing this. You don't want any sealer getting into the pump itself. Picture four shows me gently applying a shop towel to the surface to soak up the excess gasket maker. I just gently rubbed the towel and did not move it at all. Picture five shows you the results of removing the excess gasket maker by gently pealing back the towel. Picture six shows the cover installed with new "Allen" head bolts. These bolts are torqued to 35 in-Ibs. .
Picture seven shows the "Loctite 515" gasket maker.

 

[rustystud]

Picture one shows me torqueing the "Allen" bolts. Picture two shows a nice close-up of why I used stainless steel "Allen" head bolts. They are much easier to torque then "Phillips Head" bolts and they won't rust !




These two pictures show something extremely important ! This hole I'm pointing to is a lubrication passage for the pump input shaft. It starts at the gears and goes down to the end near the oil seal and uses the fuel to lubricate it. One of the pumps I tore down had a broken off drive gear for the booster pump. It destroyed the main pump cam gear and basically ruined the whole injection unit.
After disassembling the booster pump to find out what had happened I found the shaft was seized to the bore of the housing. After driving it out I found this lubrication passage was totally blocked with gunk. What had happened was the "Primary" filter had not been changed and allowed garbage to enter the booster pump. Remember, the only filtering the booster pump gets is from the first "Primary" filter. I saved the broken shaft and busted up gear if anyone wants to see it.

This picture shows the "copper" washer I installed. Normally this is just a "machine fit" and you can use a little sealant. I don't like that myself so I went to NAPA and bought some copper washers to fit here.

 

[rustystud]

I forget. This picture shows the little heel bar I used to remove all the oil seals. It was the easiest removal method and didn't cause any damage to the bore.

 

[Davidwyby]

Love this thread. I wonder why the HHs have different numbers if they're all the same...just a different spring?

What shaft seal did you use for the booster pump? The oddball NOS or the updated one with the modification per Gringeltaube?

Thanks

 

[rustystud]

Love this thread. I wonder why the HHs have different numbers if they're all the same...just a different spring?

What shaft seal did you use for the booster pump? The oddball NOS or the updated one with the modification per Gringeltaube?

Thanks

I don't have an answer about the Hydraulic Heads. I've measured them all and they are all the same. I don't have a spring gauge though so maybe there are different spring tensions. That would only be for higher RPM's though.
I went with the factory seals from AMBAC. The booster pump "kit" costs $40.00 ea. and the main gasket kit costs $50.00 ea. The main roller bearing on the cam is a "FAFNIR 205KG" . They are available all over.

 

[Davidwyby]

Scary good or scary bad ? I don't think most guys are interested either way though but I'll keep posting. Maybe someone in the future can find something here helpful.

I'm very interested. Most seem to think there's some
kind of voodoo in the IP and are afraid to mess with them, so they spend big $ on them. I'd rather DIY. I'll take all you care to post. I have an LDS with an LD pump I'd like to make into an LDS pump.

 

[rustystud]

I'm very interested. Most seem to think there's some
kind of voodoo in the IP and are afraid to mess with them, so they spend big $ on them. I'd rather DIY. I'll take all you care to post. I have an LDS with an LD pump I'd like to make into an LDS pump.

OK then, I'll keep on posting away. Though to be honest in "modern" injection pumps they are extremely complicated pieces of equipment. I was in a Injection pump rebuild class a few years ago when the ISC and ISL engines where coming out. This pump cost over $2000.00 for a rebuild then. After three of us ( I was the second to rebuild it) had successfully rebuilt it this fourth guy totally destroyed it by forcing the piston on the guide pin. None of us knew about it until it came time to run the pump. It self destructed in seconds ! There was fifteen people in that class and eleven never got a chance to rebuild a pump as they only had the one. Of course they all where eye witnesses to what not to do ! I guess that would count as something.

 

[rustystud]

One of the things that must be done on every rebuild (of anything) is after cleaning all the parts you need to check-out each part individually and repair or replace any bad or broken pieces.
This is the pump main body and what I'm doing is "resetting" the hydraulic head studs. Using my "stud remover/installer" tool I took out each stud (pic 2) and then cleaned all the rust off them (pic 3) . Picture 4, nice clean stud. Then using a tap I cleaned out each hole (pic 5) . Applying some medium grade Loctite (pic 6) I reinstalled the studs (pic 7) . As you can see in picture 8 the studs are installed all the way in. This gives me 3/16" more thread contact, and in an aluminum head this is a good thing ! At the factory the studs where set up higher to allow the use of a lockwasher, but since I will be using modern "stover" nuts (self-locking) I don't need the extra height. In my opinion this is a "win-win" situation.
Extra thread engagement and modern clamping force.

 

[gimpyrobb]

I don't have an answer about the Hydraulic Heads. I've measured them all and they are all the same. I don't have a spring gauge though so maybe there are different spring tensions. That would only be for higher RPM's though.
I went with the factory seals from AMBAC. The booster pump "kit" costs $40.00 ea. and the main gasket kit costs $50.00 ea. The main roller bearing on the cam is a "FAFNIR 205KG" . They are available all over.

All the ones you have are the same. I have one with a longer plunger than the rest. I forget the model # though.

 

[rustystud]

All the ones you have are the same. I have one with a longer plunger than the rest. I forget the model # though.

View attachment Scan0175.pdf

What you have Chris is a code "G" pump. They have a recessed "tappet" and a longer spring. It's the cam that determines the actual stroke of the plunger. The cam part numbers are the same for the LDT and LDS pumps. I have two Hydraulic Heads that came off a LDS pump and five that came off a LDT pump. All measure the same diameter and since the strokes are all identical that would equal the same amount of fluid pumped. Now the "relief valve springs" might be different. That would allow more pressure in the hydraulic head maybe increasing the total pump pressure. I measured all the drilled passages in the hydraulic heads (since I totally dismantled them). All measured the same. That just leaves the "fuel delivery valve and spring" . Now the valve is fitted to each individual hydraulic head just as is the plunger but the spring is a replaceable item. According to the TM there is only one spring listed
"2910-878-8215" . It is suppose to fall within the specs of 5.2 to 5.8 Ibs of pressure. So again the same spring for all heads. The "plunger" spring is also listed . It has a pressure spec of 17 to 19 Ibs. Again only one spring listed. It is actually quite frustrating to find everything all the same ! I was hoping to find something that stood out and said "Here I am, I'm the part your looking for !!! . I'm what makes a LDT pump into the LDS pump " . But so far there is nothing. Only the different amount of angle put on the governor linkage, and the smaller springs on the "timing advance" unit.

 

[rustystud]

All the ones you have are the same. I have one with a longer plunger than the rest. I forget the model # though.

I should have specified that the "diameters" where all the same. Again the cam determines the stroke length, and all the cams are the same.

 

[tommys2patrick]

Have you developed an opinion as to why you would need an LDS pump on an LDS engine. Other than the linkage, would you now consider them interchangeable? By the way, very impressed with your thoroughness, skill-set, inquisitiveness and your well stocked tool box. Surprised that you don't have a spring gauge. Of course there are probably as many spring gauges as there are springs.

 

[rustystud]

Have you developed an opinion as to why you would need an LDS pump on an LDS engine. Other than the linkage, would you now consider them interchangeable? By the way, very impressed with your thoroughness, skill-set, inquisitiveness and your well stocked tool box. Surprised that you don't have a spring gauge. Of course there are probably as many spring gauges as there are springs.

Thanks Tommy. After wrenching on heavy trucks and equipment for over 4 decades I have collected quite a few tools. The spring gauge I've been meaning to buy costs $500.00 used so I will have to save up for it. The wife doesn't understand my "need" for such things !
As far as the pumps being interchangeable goes, I see no reason that says otherwise. They are identical in every way. All seven pumps and Hydraulic Heads. This actually makes sense as many on this site say they just increased the fuel on there LDT pumps and got the same amount of power that their LDS units had. Gimpyrobb for one has said this in many posts. I trust his opinion very much. So now after all my searching for the "magic" part I have to say there is none.

 

[m715]

Very well done, and nicely presented rusty. They tell me I have a learning disability, I don't believe that. I just learn differently from most people. What you have done here has totally taken the Mistry of these units away.

 

[winfred]

i think you could make a quick and dirty spring gauge with a trigger pull gauge like this or many others or varying scales/ranges https://www.schooloftheamericanrifle.com/s/cc_images/cache_942819355.jpg and a couple pieces of scrap

 

[rustystud]

I finally got my special socket made (pic 1). Thank you "Peashooter" for the excellent job you did !!! In pictures 2 and 3 you see how the bearing retaining nut fits into the special socket. In picture 4 I have the bearing already installed on the "cam" shaft and pictures 5 and 6 show the retaining nut "lock" and "nut" .
In picture 7 I'm torqueing the retaining nut to 40 ft Ibs. You can tighten the nut a little bit more to allow one of the locking tabs to lock into a slot on the nut. Picture 8 shows the tab bent into the slot. Main bearing installed !
I put the shafts into the deep freeze so I can install the governor "spyder" tomorrow.