John Deere 300B injectors

[Mutt]

I see from the exploded parts book that these come apart

http://partscatalog.deere.com/jdrc/sidebyside/equipment/76650/referrer/navigation/pgId/153280

here are mine front to rear.

The adjuster on the front cylinder sticks out way further than #2 and #3
What is the FActory setting on the adjuster? I

 

[Jim.ME]

That one appears different from the others and it may just be a case of it was assembled with different parts so the thread protrusion is different. Why did you pull them? You need a service manual, not just a parts catalog. Just because it has threads and can be adjusted doesn't mean there is a simple "factory setting" anyone can make. There is a cracking pressure they get adjusted to, not measurement or torque. You have to have the proper tester to do that. Take them to a shop that does injection work. They can test them, check spray pattern, and should have new seals - if they are reusable. That type injector is normally replaced, not rebuilt, but even new injectors should be checked for cracking pressure.

 

[Mutt]

Here is the #1 disassembled as far as I can get it. I am pretty sure that cap (red arrow) on the very bottom comes off, so that white seal can be replaced. (both seals green arrows)

I held the cap in my lathe chuck and tried to turn it both directions, but neither way seems to want to unscrew?

 

[Mutt]

I removed them when I did the head tear down so I could clean the head thoroughly before I did a valve job on it (in frame rebuild)

 

[Dieseltech]

Pencil injectors have two adjustments, opening pressure first,
then needle lift. The lift needs backed off first though during
adjustment. Injectors can be cleaned, and if they work OK can
be sealed with new top compression gasket and lower carbon
dam. If bent, or have excess return fuel they need replaced.

 

[D-]

The tip does not unscrew. You are in over your head.
You should have had them pressure checked and replaced
if bad.

 

[Mutt]

They may not unscrew, but they do come apart as all the pieces have seperate part #'s

 

[Mutt]

I have only disassembled one of them. The other 2 are as I removed them, they just pull out and push back in. I mic'd adjuster stick out length before I disassembled it, so it could go back together the same way it was before.

 

[matthies]

The cap at the red arrow does NOT come off, but the white seal does.

 

[Mutt]

well I wonder why it is offered as a seperate part , if it doesn't come off?

13 - CAP
Part NumberT24472
Qty Req1

The seal feels like hard teflon or something. It's not really flexible, so how would ya get another one on there?

12 - SEAL
Part NumberR48000
Qty Req1
RemarksNOZZLE, LOWER

 

[Jim.ME]

How about this, T24472 is the vinyl cap that protects the nozzle during shipping and handling. Cost is about 90 cents at Deere.

Are you planning to overhaul the injection pump yourself as well? If so I suggest you take it and your injectors to a pump shop or pack everything up in a box and send it to Dieseltech or one of the other pump guys that post here. Somethings are best done by those who specialize in them. JMHO

 

[Mutt]

I'm gonna think about your reply and look at what's left of the injector over. John Deere can draw every part of the injector perfect, except for the bottom of the injector itself. Doesn't make a lot of sense.
What's the cost for the guys to rebuild 3 injectors? I looked around and I found most cost less than $30 each brand new. Also looked at the cost of $400-$600 to rebuild a pump, but the parts cost less than $100

 

[tomstractorsandtoys]

It takes a special tool to replace the bottom seal. It is shaped like a thimble and stretches the seal as you slid it over. If you have a Deere service manual it should show you the tool. Tom

 

[Mutt]

I will check that out in the service manual when it comes in.

 

[Jim.ME]

I doubt the guys who do these will rebuild them if they don't checkout right. They know what the competition is and can get new ones if needed.

As for cost to rebuild a pump, it is like most things. The cost usually is not in the parts required. The proper tooling, technical info, testing gear, shop supplies, parts inventory, and facilities' costs all add up, along with the value of the technician's knowledge and skill.

 

[Dieseltech]

The injector tip end is NOT removable in the field. Most
pumps I repair, test, and return are in the 350-450 range.

 

[Tx Jim]

(quoted from post at 21:21:55 02/11/20) How about this, T24472 is the vinyl cap that protects the nozzle during shipping and handling. Cost is about 90 cents at Deere.

Are you planning to overhaul the injection pump yourself as well? If so I suggest you take it and your injectors to a pump shop or pack everything up in a box and send it to Dieseltech or one of the other pump guys that post here. Somethings are best done by those who specialize in them. JMHO

Ditto what Jim.ME stated.

Spec's for vinyl cap is shown below.

 

[jd man wis]

Why do you call these injectors when there nozzles. Dont know the difference of the two of a injector and nozzle.

 

[Mutt]

(quoted from post at 20:30:35 02/11/20)
I doubt the guys who do these will rebuild them if they don't checkout right. They know what the competition is and can get new ones if needed.

As for cost to rebuild a pump, it is like most things. The cost usually is not in the parts required. The proper tooling, technical info, testing gear, shop supplies, parts inventory, and facilities' costs all add up, along with the value of the technician's knowledge and skill.

Thanks for the info, but if my injectors/nozzles all check out right, why would they need to be rebuilt?

 

[Mutt]

Thanks for the instruction. John Deere needs to update their parts book pistures

 

[Jim.ME]

(quoted from post at 10:28:10 02/12/20)
Thanks for the info, but if my injectors/nozzles all check out right, why would they need to be rebuilt?

My answer is if they checked out good with a cracking pressure (pop) test and the spray pattern was good they wouldn't necessarily need to be rebuilt or replaced. However that is recommended to be done first, before anything else is done to them. So why did you tear one apart without having them checked? Just assembling it with measurements you took doesn't mean it will be right when you finish. It should be tested, maybe adjusted, or maybe now you have to have it "rebuilt" or replaced. JMHO.

 

[Mutt]

Just not sure why you are so down on people trying to repair their own tractors. I've been working on old motors of every sort for over 30 years now. I have a fairly complete machine and welding shop. DO I know it all? Not by a long shot. Am I willing to learn new things? You betcha.

Most people have time, but a lot of people don't have a lot of expendable cash all the time. If I reassemble the one I took apart and leave the adjustment screw exactly where it was to begin with, that wouldn't change anything. It would be like I never touched it , right?

And if these businesses want to charge more to clean/adjust/ install a $1 seal into yer old one, than you would pay for brand a new one, why would one just decide to pay their mortgages and shop rent for them?

 

[Jim.ME]

(quoted from post at 12:46:40 02/12/20)

Just not sure why you are so down on people trying to repair their own tractors. I've been working on old motors of every sort for over 30 years now. I have a fairly complete machine and welding shop. DO I know it all? Not by a long shot. Am I willing to learn new things? You betcha.

Most people have time, but a lot of people don't have a lot of expendable cash all the time. If I reassemble the one I took apart and leave the adjustment screw exactly where it was to begin with, that wouldn't change anything. It would be like I never touched it , right?

And if these businesses want to charge more to clean/adjust/ install a $1 seal into yer old one, than you would pay for brand a new one, why would one just decide to pay their mortgages and shop rent for them?

I apologize if my answer offended you. I'm not down on people repairing their own and wish you luck in your endeavor. I do believe in studying into a subject before tearing into things one has not been into before. While not the detail injection pump shops have there is info about those injector nozzles on line which gives basic details of diagnosis, what to do, and how. John Deere publishes a manual about testing and servicing injection pumps and nozzles. Pop testers and adapters for the different injectors, can be purchased. Many folks have done that if they want to check their own injectors. It is recommended that even the new injectors be pop tested, as with everything these days quality varies with the sources. To do the complete testing, cleaning and repair to these is more expensive than new in many cases. From my experience, at the shop I use, if the injectors don't pop good or they see something else that makes them believe proper repair will cost too much they recommend replacement ones, not repair. I suppose some shops might go for the buck instead, luckily these folks don't.

Yes, in theory at least, if you reassemble to the dimensions it was when you took it apart it will be the same as it was before you took it apart. Without testing it will be unknown if it was right before you took it apart. Just my thoughts and opinion, and I respect yours, I hope it works out ok with your overhaul.

 

[Mutt]

No offense taken. I go to a lot of different forums and it seems like everyone seems to have unlimited cash. They all seem to tell everyone to just "go buy new ones"

I just emailed a fairly local injector shop in the Dallas area and asked them for a quote to test/adjust these 3 injectors. I'll post their quote

 

[Mutt]

here is the first quote
John Deere 300B pencil injectors
Wed, Feb 12, 2020 11:47 am
Dieselworks Ntx [email protected]
To Charles Hallam [email protected]
What kind of injectors are they ? what kind of vehicle? we charge $40 an injector.

here is the second one
Able Fuel Injection Service [email protected]
To Charles Hallam [email protected]
$80 each factory exchange

I can buy a set of 3 new ones for $75, free shipping so I think i'll buy these instead of pay thru the nose