# JD 4020 need to pull injectors



## fixingMY4020 (Aug 3, 2021)

I have a 1967 John Deere model 4020 with synchro trans, diesel, and I believe fairly low hours. Due to my work situation I failed to start it for about 2 years. Now its seized up and I am choosing to spray something like a snake oil into the cylinders to see if it can be freed up. I am opening this discussion because I am not very familiar with doing maintenance on it and want to get feedback from experienced people. I don't want to break anything.

We can talk more about what can/should be done later, right now I am hoping to keep the discussion on track with tips
on how to get my plan into action.

First things first, I am trying to remove the hood to gain clear access for injector removal but I don't really know what must be done, for instance, how does the air cleaner pipe cap come off as the hood must rise up over it? Or does the whole pipe pull up and out? And what other steps are involved with getting the hood off?

I am eager for some detailed howto advice on getting it apart.


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## SidecarFlip (Mar 25, 2021)

Use PBlaster or a mix of acetone and red ATF in the cylinders, just not too much. Far as the hood and injectors, don't have a clue.


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## Tx Jim (Jul 28, 2020)

To remove hood on a 4020 remove 1 bolt on each side at the rear of hood after removing the side shields that have spring loaded pins. Then remove side screens by pulling on the top of the screens. The screens have springs attached at the top & 2 pins that rest in holes at the bottom of each screen. Then turn spring loaded pin on each side to free the hood. Pre-cleaner bowl taps upward off of pipe. Raise hood up off breather pipe & muffler. '67 model should have pencil injectors which normally are easier to remove than the older larger injectors. IMHO once injectors are removed you can put as much snake oil in open injector hole that you desire. If crankshaft rotates the pistons will push excess fluid out injector hole. Are you aware that there's a flywheel timing window hole on RH side of clutch housing that you can remove the cover held on by 2 screws then utilize a large flat blade screwdriver or bar in flywheel ring gear to hopefully turn flywheel. Good luck on your venture.


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## thepumpguysc (Jan 25, 2015)

Pencil injectors are a nitemare, imho..
I wouldn’t even think about removing them without the proper tool..& a day to soak them before attempting the removal..
They’re real easy to bend..
The tool is a slide hammer w a fitting on the end that slides into the cut outs in the injectors..
Most places just sell new injectors and don’t require a core, so it’s your choice.


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## SidecarFlip (Mar 25, 2021)

OP stated his engine was locked up from sitting unused for 2 years. I wonder what exactly he means by locked up. Usually they don't lock up from sitting unless water got in the bores and rusted the rings to the liner walls...


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## Tx Jim (Jul 28, 2020)

Maxmax
I've owned several diesel powered trucks/tractors since '87 & have never had the need or desire to install a NEW inj pump. Before '87 I was employed by a JD dealer for 21 yrs & VERY rarely was a NEW IP required.


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## fixingMY4020 (Aug 3, 2021)

Ok, these are exactly the kinds of tips I was hoping to get! I am grateful, the hood is off. And I did try to budge
the ring gear but got no movement. 
I'm thinking either condensation or outright rain water has produced rust inside the cylinders. Hoping to find a way 
see in through the injector hole to determine better what has happened.


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## FredM (Nov 18, 2015)

That is a great looking tractor you have there, I did a search on it and it looks a beauty, I hope your problem is not major and the fix is easy.


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