Removing injection pump on JD 750

[JoeJChin]

Looking for some help .

I have a JD 750 that i would like to take the injection pump out of .

Can i just pull it out , and as long as i don't change anything , and replace all the shims , just re-install it without worrying about changing the timing ?

thanks

Joe .

 

[jimdiesel1]

Yes, just keep everything clean and you will be fine.

 

[Barry 1]

You have to unhook the governor spring etc. first or it can easily be damaged.(internal) Take off the access plate to get to it.

 

[Willl]

Just curious Joe, why the need for removal ?

 

[JoeJChin]

I want to try and see if the rack ??/ plunger ? that controls the fuel flow is actually moving .
I had an earlier post about shutting the tractor down to re-fuel it , and not being able to get it started again
I did not run it out of fuel , just wanted to add a couple gallons before starting another job with it .

Tried several things to get it started again , including bleeding all the lines (several times) .

I don't seem to be getting any fuel to the injectors .

Looking in the tech manual to see if there was something that could have come loose in the linkage that contols the injection pump , shut off ???

I took off the inspection plate on the side of the engine , to see what linkages , springs , etc , move, when operating the throttle from shut off to full throttle.

There doesn't seem to be any movement on the rack(or rod) on the pump that takes it from full throttle to the shut down position ....

Thought i might be able to see if anything was stuck or broken when i shut it down to refuel it .

I can't think of any other reason that it wouldn't start back up , just kind of feels like it might be stuck in the shut off position .

I might be , (and probably am) way off base with this idea , but thought i would try and take a look , if it isn't to complicated.

thanks for the replies.

Joe

 

[JoeJChin]

Well
I pulled the loader off today so i could get a better look at the linkages inside .

Looking at the rack on the pump , it doesn't seem to move at all when moving the throttle lever from off to full throttle .

Not sure how much it is actually supposed to move , of if it might be stuck in the off position, or if something in the linkages is messed up .

Don't know where to go next .

Might just pull the pump and see if the rack moves when out of the machine .

thanks

Joe

 

[tlblv]

Hi Joe
Know it's been a while since you made this post. Just wondering the result. I also have a John Deere 750 that's having issue pumping fuel

 

[beenthere]

Hi Joe
Know it's been a while since you made this post. Just wondering the result. I also have a John Deere 750 that's having issue pumping fuel

Welcome to TBN

But best to send a PM to Joe, not rely on seeing your question. Click his forum name and you can send a PM as well as see when last active.

 

[thepumpguysc]

Personally I’ve never taken one off.. which is odd because I’ve done a lot of those pumps.. My guess is, they’re so easy to remove and install, no one needs my help..
Rereading the original post, I gather there’s an inspection plate that allows access to the pump linkage..??
The pumps control rack will sit in a “V” or a hole in the engine linkage..
Good luck and please let us know how it went..

 

[tlblv]

Thank you beenthere and pump guy .... I will PM Joe.
This is my first tractor and first diesel engine so I'm obviously a bit concerned about the process. Your comment pumpguy makes me feel a bit better. Either they just never need to be removed because they never break or it's so simple...

Can it really be as simple as removing the fuel lines, removing the 4 nuts and sliding it out the top?

 

[tlblv]

thepumpguy.. you are correct. There is a small access panel. Inside the panel on the left you can see two gears. Directly in front you can see cams. I'll try to upload some photos tomorrow.

I'm having a very similar issue. I'm getting no fuel to the lines past the injector fuel pump... The pump appears to be totally mechanical. I do not see any wires attached or in the near area.. is it possible there is some type of electrical connection that prevents fuel from passing through? This is a barn find, 83 John Deere 750.

 

[thepumpguysc]

Lol.. wishful thinking..

 

[thepumpguysc]

Just take it out and see if the control rack moves back and forth (slider)
DO NOT FORCE IT.. there are tiny gears inside that WILL BREAK..if u force them..
And I’m just gonna put it out there for the world to see:
I charge EXTRA if the customer has been in the pump before I get it..
It takes me longer to figure out what’s messed up and what they broke..
Call it a curiosity tax..
And then they wanna b!tch about the price.!!!
It wouldn’t have cost THAT MUCH if’n they stayed out of it.!! Lol

 

[tlblv]

lol... I get it! Believe me, I don't want to go deeper into it any more that I have to... I'll pull it and slide it and let you know.. might be another rebuild in your near future (but i hope not )

 

[tlblv]

Personally I’ve never taken one off.. which is odd because I’ve done a lot of those pumps.. My guess is, they’re so easy to remove and install, no one needs my help..
Rereading the original post, I gather there’s an inspection plate that allows access to the pump linkage..??
The pumps control rack will sit in a “V” or a hole in the engine linkage..
Good luck and please let us know how it went..

... Here's where it stands...
I removed the inspection plate and got a lay of the land and see that a linkage connects to the "lever??/rack??/plunger??" of the injector pump. I removed the 4 nuts holding the pump and manipulated the "lever" to get it out of the linkage connection being sure to not bend anything.
When I attempt to "pull" the injector pump out of the housing, it seems to be bound by something.
I've removed two of the studs thinking I may not be pulling exactly straight up and that it might be binding on the studs... no change
It seems to be binging on something on the inside and it's defiantly NOT connected to the linkage.... any thoughts?

 

[tlblv]

meant to mention.. I also tried to move the "slider" of the pump while it's in the housing and it will not move.. will try again once I get it out of the housing

 

[thepumpguysc]

Is the pin on the pump or the pump rack grabbing the side of the hole.??
If yes, u have to slide the control rack a smidge to clear the hole..

 

[thepumpguysc]

Lol.. u posted as I was pushing the post button

 

[thepumpguysc]

If u push the pump back down, can u reach the pump rack.?? (Slider)
Ur gonna have to move it to clear the housing..

 

[tlblv]

Yes, I can reach the slider but not by hand. It's too far back.
The slider which is part of the pump is not connected to the linkage. It is not in the "v" or "o" (can't tell which, parts diagrams show it as a "v"). Either way, it is NOT inside that linkage. Manipulated the linkage off the slider with a hook pick.
Currently, the slider of the pump will not slide either direction. I've tried moving it with a flat head screw driver. What happens if I take a pry bar and put some leverage on either the slider or either end of it's rod?
You know of a trick to free up the slider while it's in the housing?
Was thinking there might be a cutout/slot where the slider needs to align for clearance... ?