MD Fuel priming issues

[rustred]

Hey guys got a chance to look at the md today tried the air in tank thing still no prime. Started cracking lines
and found good fuel flow out of tank but minimal flow at water separator and lot's of air in separator pulled
the line and it's full of a black tar like goo. Got it soaking tonight but i sure hope it's not like that inside the
pump. Not going to be able to work on it again for a few days but will let you know what happens. Thanks for
the tips

How long since this tractor was running ?

 

[bud from bc]

I thought about 5 years but looking at some old invoices it's closer to 10

 

[rustred]

I thought about 5 years but looking at some old invoices it's closer to 10

That’s good to know as we should have had that info also. The pump will need work also with the rack being stuck is pretty much a guarantee. I have run 20 and 30 year old diesel. Diesel dont usually plug lines unless they are dry and got full of rust. This might be algae contaminated.

 

[bud from bc]

I did mention it was sitting for over 5 years in an earlier post. Thinking i'm going to have
a lot more cleaning to be done. Anyone have any luck with seafoam

 

[used red MN]

I did mention it was sitting for over 5 years in an earlier post. Thinking i'm going to have
a lot more cleaning to be done. Anyone have any luck with seafoam

I’ve seen it posted on here that E85 is a good solvent for cutting stale diesel.

 

[rustred]

I did mention it was sitting for over 5 years in an earlier post. Thinking i'm going to have
a lot more cleaning to be done. Anyone have any luck with seafoam

If it’s like u say , it’s a disassembly project. It has to be running to use sea foam to help with gummed up parts. Them potions are not what people think, that they are something magical. And to check for a stuck rack disconnect the linkage at pump. If the throttle lever on pump barely moves , it’s stuck. Plus when u changed filters just looking at them tells a story also. Like were they reasonably clean or a rusty mess. And another thing ??? Did the tractor sit with diesel in the tank or was the tank empty. That is the million dollar question.

 

[bud from bc]

The tractor sat with fuel in the tank filters looked good no rust or black goo. Will try the throttle with the linkage
disconnected seemed to move ok with linkage hooked up. Will be back at the shop in a couple days

 

[Powered By IH]

Alright, let's see here.
First order of business is to clean the fuel lines. I have heard that acetone or laquer thinner works good for that too, never tried it though.
Another easy indicator of pluggage is unscrewing this bolt (in blue), because that is actually a little screen for the primary pump. If any goop made it to here, the primary pump probably needs to be gone through. But if that filter is relatively clean and the line (in green) is clean than you might be golden for that part.
An indicator of the injection pump is pulling one or a couple injection lines and seeing if they are clogged. If they are clogged, well, then, your injection pump needs to be gone through. But you say the filters looked fine? You might get lucky. It might be helpful just to take off all of the lines at one time and see what each one looks like inside.
It wouldn't hurt either to take the filters back off and make sure that the passages inside your filter base are clean too.

And like rustred said your rack is probably stuck. But frankly, that's easy to fix later once you get fuel to the injection pump.

Good luck and stay safe!

 

[bud from bc]

Hey guys got back to working on the MD today got all the fuel lines cleaned out only one that was really bad
was the main line to the separator. Fuel screen at primary pump was clean got everything bled and have good
pressure to injection pump but nothing going thru pump. Thinking the rack or cam in pump is stuck. Might be
a little over my head disassembling the injection pump. Going to wait till a puller friend of mine gets back from
his winter home and watch how he disassembles it. Thanks for all your guys help in getting me this far will keep
you guys up to date once we get it running again

 

[Powered By IH]

Glad to hear your progress thus far! Thankfully more lines weren't plugged.
Before waiting for your puller friend try this first:
Disconnect the throttle control at the top of the injection pump control lever. Take off the oil fill tube on the injection pump. Inside you will see the fuel rack to the right (engine side) of the injection pump. Take a screwdriver or punch and lightly work that rack back and forth. You can use solvent or WD40/PB Blaster, but very little at a time. Patience is key.
Pump rack should be unstuck when the injection pump lever moves freely, and the rack inside moves freely.
If that doesn't work, then the pump will have to be taken apart.
Good luck!

 

[bud from bc]

Thanks for that will try that when i get back to it. I did unhook the linkage
and it moved but was a little stiff. Is it a little risky to squirt a little penetrant
down the injector tops at the top of that picture?

 

[used red MN]

Thanks for that will try that when i get back to it. I did unhook the linkage
and it moved but was a little stiff. Is it a little risky to squirt a little penetrant
down the injector tops at the top of that picture?

Penetrating oils are hydrocarbon(Dino juice/crude oil) based and surprise so is diesel fuel, squirting penetrating oil on there will harm nothing. The only risk is causing crud to flow down where it shouldn’t. Also using brake clean or ether you just have to make sure any wear or rub surface is re-lubed with something. In most cases the outlets that the injector lines connect to have “delivery valves” essentially check valves that hold the fuel in the injector line. So in most cases something sprayed in those outlets cannot enter there to get down into the plungers.

 

[bud from bc]

Penetrating oils are hydrocarbon(Dino juice/crude oil) based and surprise so is diesel fuel, squirting penetrating oil on there will harm nothing. The only risk is causing crud to flow down where it shouldn’t. Also using brake clean or ether you just have to make sure any wear or rub surface is re-lubed with something. In most cases the outlets that the injector lines connect to have “delivery valves” essentially check valves that hold the fuel in the injector line. So in most cases something sprayed in those outlets cannot enter there to get down into the plungers.

Thanks kinda thought the might have a check valve. Going to try and make sure rack is free and
try it again

 

[rustred]

Thanks kinda thought the might have a check valve. Going to try and make sure rack is free and
try it again

It’s nothing to do with spraying the outlets. U need to remove the oil fill cover with the 2 1/4” bolts. Then you will see a little rack and pinion set up with and adjusting bolt Gently see if you can tap this bolt Ahead and work if back and forth. I’ll post u a pic Tommorrow. And yes spray all u want in there. Then drain and change the oil in pump once it’s freed up. If it’s really stuck then you need to pull the top off the pump.

 

[used red MN]

It’s nothing to do with spraying the outlets. U need to remove the oil fill cover with the 2 1/4” bolts. Then you will see a little rack and pinion set up with and adjusting bolt Gently see if you can tap this bolt Ahead and work if back and forth. I’ll post u a pic Tommorrow. And yes spray all u want in there. Then drain and change the oil in pump once it’s freed up. If it’s really stuck then you need to pull the top off the pump.

Don’t that picher in replys 8 do the job?

 

[rustred]

Don’t that picher in replys 8 do the job?

You mean the one full of scotch ?don’t know hate scotch .

 

[used red MN]

You mean the one full of scotch ?don’t know hate scotch .

Sorry thought U would understand that. Some how I misread the number, picture in reply 30.

 

[bud from bc]

Hey guys got a chance to look in the pump today and i'm a little confused on how the
rack works. Looking in the oil fill hole there are two bolts on the left that are moving
freely with the throttle and one single bolt with a lock nut on the right that looks like an
adjustment. Is that bolt supposed move with the throttle also. I tried a bit of force on it
but want to make sure i'm not going to screw something up. Thanks for bearing with me
on this

 

[used red MN]

and one single bolt with a lock nut on the right that looks like an
adjustment. Is that bolt supposed move with the throttle also.

This is what should move forward and backwards. It should look like what Powered by IH posted circled in his photo. In that photo the pump plunger unit is removed. The gear teeth (rack) you see in the next hole forward turn a gear in the plunger unit which controls the amount of fuel delivery. The “rack” is also connected on the opposite end by a lever going down to the governor that is lower in the pump.
Don’t use a lot of force if you achieve any front and back movement just keep wiggling it back and forth attempting to increase the motion. Check your Direct Messages I will give you some additional info to reference there.

 

[rustred]

Hey guys got a chance to look in the pump today and i'm a little confused on how the
rack works. Looking in the oil fill hole there are two bolts on the left that are moving
freely with the throttle and one single bolt with a lock nut on the right that looks like an
adjustment. Is that bolt supposed move with the throttle also. I tried a bit of force on it
but want to make sure i'm not going to screw something up. Thanks for bearing with me
on this

Here u go.