Rebuilding the Injection pump

tommys2patrick said:

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.

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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.

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.

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

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.

I installed the governor "spyder" today. In picture 1 you can see the assembly lube I used on the bushing in the main housing. Picture 2 shows the governor heating up. Picture 3 shows the cam shaft installed ready for the governor to be installed. Picture shows the governor installed. Even though I had the cam shaft in the freezer and heated up the governor it still took some persuasion with a brass punch to seat it.

Stop working and go to Alaska.

I have a brand new ambac if you don't want to repair that one

Me too...

CARNAC said:

I have a brand new ambac if you don't want to repair that one

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What fun is that ? That is half the fun of owning one of these trucks. Being able to rebuild what is broken and bringing it all back to life is what mechanics do. I might be retired now but I'm still a mechanic .

Pic 1 shows the main bearing retainer installed. Pic 2 shows the "timing hub" being installed. I used the gear nut to tighten the hub in place (55 ft Ibs) then installed the "cam shaft nut" and using my spanner wrench held it in place while tightening it. Then I installed the set screw (25 ft Ibs) picture 4 . Picture 5 shows the "quill shaft" and picture 6 shows it installed. I installed the timing hub first since I could hold it and align the scribe mark (pic 7) while installing the quill shaft since the "open" area (pic 6) needs to align with the casting mark near the piston. This is very similar to installing a distributor on an engine as the gear rotates as it is installed. Picture 8 shows the piston and spring and retainer. Picture 9 shows the piston installed. Remember there is an alignment pin the piston slides on. You can see it in picture 6 .

Picture 1 shows the piston spring installed. Picture 2 shows the snap-ring and picture 3 shows the retainer and snap-ring installed.

This last picture shows the two pumps I'm assembling. Out of the seven pumps I disassembled, I only got enough good parts to make-up two good pumps. These are very robust pumps though. Everyone of them had been rebuilt several times. One had been rebuilt over 3 times. So all in all that is not to bad for a precision unit.

There was one last thing I forgot to mention about the LDS versus the LDT pumps. The first picture shows the different lengths of spring used for the timing advance on the pumps. The one on the left is from the LDS and the longer one is from the LDT pump. The shorter springs on the LDS would allow the pump to advance quicker then the LDT pump. This does not increase the amount of fuel but it would allow for a faster revving engine.

First off I just want to say that this whole thread is not a step by step instruction for the assembly of the deuce injection pump. It is an aid to the TM manual. There are spots where the TM falls short in explanations and hopefully this thread will help. In pictures one and two I'm checking the end-play of the "timing device" . The TM does not show clearly where to measure from. It is from the base to the end of the thrust-washer. I see my pictures of checking the input shaft end-play did not come out so I will take new pictures tomorrow. Picture three shows the input shaft and the two "selective" thrust-washers. Pictures four and five show the correct way to install the washer and timing device to the input shaft and weights. Picture six shows the assembly ready for the housing to be installed. Picture seven shows the long bolt (bolts into the pump flange) which must be installed at the same time the housing is. Picture eight shows the two pumps now with the front housings installed.

This is just a little bit of trivia but still interesting. As far as I know there where at least two manufactures of the deuce injection pump. The first is of course "American Bosch" . The second was "United Technologies" . United Technologies made the housings thicker then Bosch did as seen in pictures one through five. The last picture shows the governor housing. The Bosch pump is on the left and the United Technologies is on the right. Note the position of the end cap bolts.
The internal parts are all identical though. Just something interesting I thought I would share.

from post #32
"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."

So gear pump dies + truck don't go no more.
Thanks rustystud

I need to mention this little screw. It blocks off the pumps main oil pressure. If it comes loose or you forget to install it after a rebuild you will loose all oil pressure in the pump. I took mine all out to thoroughly clean the camshafts. Then I used Loctite and tightened them back on.

This is another thing that needs attention. The fuel shut-off assembly. On everyone I took apart they all had crud and rust on the shafts. In picture two I'm removing the roll pin. Then you can see and clean the whole shaft and the 'O' ring that should be replaced.

Before I started on the governor assembly I reinstalled the main housing oil supply fitting. This is just easier before the housing is on.

The TM says to install the "sliding sleeve" on the "fulcrum" then install it on the camshaft, but I found it much easier to install the sliding sleeve on the shaft and into the governor weights first (pic 1 & 6). Then you install the fulcrum into the housing (pic 2) then the oil baffle goes in (pic 3 & 4). Now install the housing and slide the sleeve into the fulcrum (pic 5). The operating shaft assembly must be off for this as you need the space to adjust the sleeve into the fulcrum. Make sure the sleeve is fully engaged into the fulcrum and the fulcrum is engaged into the housing stud (pictures 7 & 8 ) . Then install the bolts and tighten it up.

Now I need to install the operating shaft assembly and install and adjust the governor springs.