# JD955 Fuel Injector Removal



## Tater50 (Dec 17, 2011)

This one has been sitting for years; 2 & 3 cylinder are firing well; number 1 is not firing. This is a Yanmar 3TN84. Can it be removed & cleaned & How difficult is it to change one out & what special tools are needed? I tried some Lucas for about 1 1/2 hrs; but it did not help.


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## thepumpguysc (Jan 25, 2015)

U need an injector "puller".. all it is is a slide hammer w/ the correct fitting that screws onto the top of the injector..
IF u have a parts store that rents tools, they'll def. have 1..
There are 2 diff. thread sizes on injectors.. a 12mm & 14mm just so u know..


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## Tater50 (Dec 17, 2011)

Thanks: do you know the part number for a replacement?


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## Tater50 (Dec 17, 2011)

Anyone remove one of these before? According to my research; it can be a pain!!!


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## thepumpguysc (Jan 25, 2015)

They ARE if u don't have the injector puller.. U stand a very good chance in bending the return fuel stem..
Your injectors for a 955 should have the "male external threads" straight up..
{12mm I recall} that u screw on an adaptor to fit the inj. puller{slide hammer}
IF U have the "female internal threads" at a 90* angle.. u don't have a 955.. its either a 6 or 750..


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## Tater50 (Dec 17, 2011)

Will take your advice; as you suggested, I can get one at the parts store. Will LUK the results. You have been a great help!! Have you ever used Diesel Kleen or something comparable? I was going to use some & operate the JD for a full tank to see if it may jar some contaminants loose (if that is the case). It could be just shot!! I'd rather try that before the purchase & removal; I am preparing this to sell, since I have 2.


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## thepumpguysc (Jan 25, 2015)

Are u SURE its an injector & not the pump.??
U could swap injectors, once u figure out how to get them out or get the correct PULLER.


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## Tater50 (Dec 17, 2011)

If pump was bad; wouldn't I have problems w/the other 2?


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## bmaverick (Feb 20, 2014)

Tater50 said:


> If pump was bad; wouldn't I have problems w/the other 2?


yes and no. depends on what failed in the pump.

Have you jumped over to any of the Deere parts sites to look at an exploded diagram of how these parts fit together and sizing? This will really help you and thepumpguysc working together.


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## Tater50 (Dec 17, 2011)

I saw some diagrams of all the parts; shims; etc & was considering breaking it down & cleaning it; but I have 2 955's' so I am putting this one up for sale and listing the number 1 fuel injector as misfiring. I got so many irons in the fire; I will give a discounted price to someone who has the time to do it. I do thank you for ALL the info.


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## thepumpguysc (Jan 25, 2015)

U could ask for a lot more if it was "purring"..
Its prob. an easy fix for someone that has the time and a torque wrench.. prob. less than 100.00.


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## bmaverick (Feb 20, 2014)

Tater50 said:


> I will give a discounted price to someone who has the time to do it. I do thank you for ALL the info.


Where is the next big town to you? This way, if any of the folks here need a machine ....


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## Tater50 (Dec 17, 2011)

I live 55 miles south of Atlanta. My part is AM877675 w/an external male thread. I think 12mm; so I cannot find a puller that I can borrow from a parts store & they are real expensive just to pull one injector; I plan to buy a FM threaded coupling & make my own. Will let you know how it comes out.


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## bmaverick (Feb 20, 2014)

Tater50 said:


> I live 55 miles south of Atlanta. My part is AM877675 w/an external male thread. I think 12mm; so I cannot find a puller that I can borrow from a parts store & they are real expensive just to pull one injector; I plan to buy a FM threaded coupling & make my own. Will let you know how it comes out.


Wow, you are very near the John Deere and Yanmar plants that made your tractor. 

Depending on the injector, if it's clogged, you can use an ultrasonic parts cleaner and Seafoam to clean it. Takes about 20-30mins of time.


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## MutantGenepool (Nov 1, 2019)

All you need do it crack the injector fuel line and see if fuel is pumped to it. Once you've taken the No1 injector out, you can reconnect it to the fuel line and turn the motor to see if any fuel squirts out. BE SURE TO STAND AWAY FROM THE INJECTOR.
You can check the Tappets clearance as well if fuel squirts.


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## bmaverick (Feb 20, 2014)

MutantGenepool said:


> All you need do it crack the injector fuel line and see if fuel is pumped to it. Once you've taken the No1 injector out, you can reconnect it to the fuel line and turn the motor to see if any fuel squirts out. BE SURE TO STAND AWAY FROM THE INJECTOR.
> You can check the Tappets clearance as well if fuel squirts.


AND place a bucket under it, or towel or something.


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## Tater50 (Dec 17, 2011)

Already cracked the line; plenty of pressure & fuel. Will remove & soak; sounds like a winner


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## Tater50 (Dec 17, 2011)

I was thinking since I am going to remove the injector to allow it to soak in Sea Foam; why not disassemble; clean & reassemble. Can that be done & what is the degree of difficulty? The diagram that I have looks like the base of the injector is retained by a threaded nut-like & the middle section looks like a spring w/some o-rings. I will let you know what happens.


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## thepumpguysc (Jan 25, 2015)

There are NO Orings in the injector.. those are shims..
DO NOT lose the shims.!!
Soaking the nozzle/tips separated from the injector body, is the only way to clean them..
Soaking them whole, in a pan, does nothing..
U NEED a torque wrench to tighten the "nozzle nut" to 50-55 ftlbs..


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## Tater50 (Dec 17, 2011)

thepumpguysc said:


> There are NO Orings in the injector.. those are shims..
> DO NOT lose the shims.!!
> Soaking the nozzle/tips separated from the injector body, is the only way to clean them..
> Soaking them whole, in a pan, does nothing..
> U NEED a torque wrench to tighten the "nozzle nut" to 50-55 ftlbs..


Thanks for the sound advice; will let you know the outcome.


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## Tater50 (Dec 17, 2011)

thepumpguysc said:


> There are NO Orings in the injector.. those are shims..
> DO NOT lose the shims.!!
> Soaking the nozzle/tips separated from the injector body, is the only way to clean them..
> Soaking them whole, in a pan, does nothing..
> U NEED a torque wrench to tighten the "nozzle nut" to 50-55 ftlbs..


Thanks: Now to find a puller; do you know the size that I need to attach to the injector? Need to rent one; but did a search & could not find the mm size!!


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## thepumpguysc (Jan 25, 2015)

Good God Man.. go back & LOOK at post #2.


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## Tater50 (Dec 17, 2011)

thepumpguysc said:


> Good God Man.. go back & LOOK at post #2.


In the post it says: "There are 2 diff. thread sizes on injectors.. a 12mm & 14mm". I did not want to buy a 12mm & it be a 14mm. I do not know if they come in an assorted kit!! No need to get upset about a legitimate question. I have basic mechanical knowledge but do not work on tractors on a daily basis.


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## pogobill (Jan 31, 2012)

I don't think anyone is upset Tater50. A few folks are trying to get you through your issue, and seeing as there is getting to be quite a few posts in this thread, it may be a getting a bit tough to recall all the info. A quick review may be in order to fit all the information together. 
A few pictures may help identify what you are doing and what you may need to get you going again.


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## marc_hanna (Apr 10, 2017)

There are injector pullers on Amazon that have an assortment of adapters for each size and type of injector. I put a little acetone and penetrating oil around the injectors and get the engine good and warmed up before I try to pull them. Depending on the style of injector, smear some high temp ceramic grease on the outer surface that mates with the injector bore before reinstalling. This will make it much easier to get out in the future.


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## Tater50 (Dec 17, 2011)

Thanks to ALL: looks like a kit w/assorted connectors will be the way to go; since I may need them for another tractor down the road.


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## deerhide (Oct 20, 2016)

Tater50 said:


> Thanks: Now to find a puller; do you know the size that I need to attach to the injector?  Need to rent one; but did a search & could not find the mm size!!


I have popped an injector out by undoing the hold-down bolts and the fuel line then turned the key. I don't know if this way would work for you though.


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## marc_hanna (Apr 10, 2017)

Here’s a diagram I found. It looks like you have to copper seals and fibre washer that will need to be replaced. You may need to recut the seat as well.


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## marc_hanna (Apr 10, 2017)

deerhide said:


> I have popped an injector out by undoing the hold-down bolts and the fuel line then turned the key. I don't know if this way would work for you though.


I’ve heard of people doing that also, but never tried it myself. I know of a guy that regularly does that on Sprinter vans, which have a long pencil style piezoelectric injector, so I imagine it would work all that much better on a stubby one.


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## thepumpguysc (Jan 25, 2015)

A regular injector puller will not work on that type of injector..
See where the "inlet" is.. "sideways"..
Hoye tractor sells & rents a puller just for that injector.. They are the only ones that make it as far as I know & its "priority" to Hoye..??
When I worked on them, the only thing needed was to replace the fiber washer directly under each injector..I think it cost 1.00.. & I replaced 1 injector..
They rent that tool for cheap for 10 days.. & the shipping was 25.00.. its BIG & HEAVY.
I opted to buy the tool tho.. I figured it wouldn't be my only 1..
I would offer to loan u the tool but I have no idea how I would ship it.. as I burned the box it came in..


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## marc_hanna (Apr 10, 2017)

thepumpguysc said:


> A regular injector puller will not work on that type of injector..
> See where the "inlet" is.. "sideways"..
> Hoye tractor sells & rents a puller just for that injector.. They are the only ones that make it as far as I know & its "priority" to Hoye..??
> When I worked on them, the only thing needed was to replace the fiber washer directly under each injector..I think it cost 1.00.. & I replaced 1 injector..
> ...


Can you put an open end wrench on these injectors and leverage them out?


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## thepumpguysc (Jan 25, 2015)

U have to remove the hold down studs using the "double nut" method..
THEN u can get an adjustable wrench on it.. BUT BE WARNED.. the opening for the line, where it hooks to the injector.. is VERY SOFT metal.!! do be careful WHERE the jaws land.. IF u try to turn it & the wrench jaws are in the opening.. U WILL crush it.. & theres no opening it back up.. I found out the hard way, many years ago..
What I did was, remove the injector line from the PUMP & screw it back into the INJECTOR.. {flip the pump end out of your way..}
THAT WAY, the opening is supported & it CANT crush..
Good luck..
U may not even need all this information.?? Have u even TRIED to remove them.??
Another trick is to loosen the hold down nuts till they're almost off.. & spin/crank the
engine.. They might just "pop" out..


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## thepumpguysc (Jan 25, 2015)

Once they're out.. contact me & I'll tell u how to replace JUST the nozzle for 30 some bucks instead of paying 88-90 some dollars for an injector..


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## bmaverick (Feb 20, 2014)

H


Tater50 said:


> Thanks: Now to find a puller; do you know the size that I need to attach to the injector? Need to rent one; but did a search & could not find the mm size!!


Hey, got my Harbor Freight email this morning. AND guess what they have?

*Fuel And Transmission Line Disconnect Tool Set, 7 Pc.*
https://www.harborfreight.com/merch...sion-line-disconnect-tool-set-7-pc-64813.html

Get the 20% off coupon and see if these can get those injectors off.


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## thepumpguysc (Jan 25, 2015)

On a regular, 95% of all injectors..{in the U.S.} the inlet it "straight up".. & u can screw an adaptor onto it, after u remove the line of course.. & screw your slide hammer onto the adaptor & "pound it" UP..
IF the injector is like that in the diagram above.??
A "regular" slide hammer & adaptors, WILL NOT work.. because of the position & configuration of the inlet.. its "side ways" instead of straight up..
WITH "female" threads.. instead of male..

IF the injector is stuck.?? We still don't know that YET..
When u go to "wiggle it".. the injector will come apart.. leaving the NOZZLE NUT along w/ the nozzle STUCK IN THE HEAD.. & all u removed was the "body" of the injector..
The way the Hoye injector remover works is>> their adaptor has the same threads as the body of the injector..
SO all u have to do is.. screw it into the NOZ. NUT that's stuck in the head & "pound it" UP..
I hope that clears up any questions..


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## thepumpguysc (Jan 25, 2015)

I forgot to mention 1 VERY CRITICAL instruction.!!!
When u go to wiggle it loose w/ your wrench..
TURN the wrench CLOCKWISE & see if the inj. turns.. if it does, GREAT, your home free..
If it doesn't budge.. DO NOT TURN IT COUNTER CLOCKWISE..
Just keep spraying it down w/ penetrating oil for a day or 2 or 3.. & hope it comes out turning it CLOCKWISE..
Because once u turn it COUNTER.. & put some force behind it.. u stand a very good chance in unscrewing the body from the nut.. & THEN your sunk.. u HAVE TO get the puller..


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## Tater50 (Dec 17, 2011)

Thanks to all; this is not a 911; I am recovering from a major surgery & ASAP will tackle the job & give updates. Here is a pic of injector; from what I see on the Yanmar Tech Manual that Mr. Tommy of Yanmar sent to me today, this is the "hole type"; not "pintle!! I "NEVER" figured that Yanmar would send me info on something 21 yrs old. So awesome to all whom have replied & Yanmar. I will send pics of the way that I disassembled; etc!!


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## thepumpguysc (Jan 25, 2015)

A REGULAR slide hammer inj. puller will remove it..
To figure out if its a 12 or 14mm thread.. remove the line & with an open end wrench, use it to put around the threaded part.. if the 12mm fits snug around the threads, then that's it..
Now try it w/ the 14mm.. is it real sloppy.. then that's NOT IT..


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## Tater50 (Dec 17, 2011)

thepumpguysc said:


> A REGULAR slide hammer inj. puller will remove it..
> To figure out if its a 12 or 14mm thread.. remove the line & with an open end wrench, use it to put around the threaded part.. if the 12mm fits snug around the threads, then that's it..
> Now try it w/ the 14mm.. is it real sloppy.. then that's NOT IT..


It is a 12mm but not 1.25, 1.5 or 1.75 pitch thread; none screw down more than a 1/8". The only thing that fits (but a little loose till I go all the way down) is a 3/8ths( I think; do not believe it is 1/2") brass coupling. My research has stated that Japan uses British Standard Pipe (could be wrong); which I am searching further. I am on a fixed income & this is not a 911; so I am having to see if I can fabricate a cheap slide hammer. I do plan to use ALL above info in reference to operating till warm; then loosening the retainer nuts; then operating to see if it will push it out!! But I still need to make one for future use; since I purchased 2 of these 955's. Thanks for the input.


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## Tater50 (Dec 17, 2011)

UPDATE: SEE PICS!!! I finally got to the Injector. Flare nut that attaches to injector can be removed w/a 11/16th wrench. I had tried 12mm nut x 1.25; 1.5 & 1.75 to make a slide hammer; & NO fit. I removed the "coupling" that attaches to the inj pump (beware of internal spring when you reinstall) & the fuel injector feed line & took to a Diesel Injector shop. (While line was removed; I cleaned it) They fitted it & sold me the flare FM fitting(he did not know the size of the nut). The tech said the "best" item better than WD40, etc. was a product used by aviation called "Mouse Milk"; but Blaster would work OK!! I took FM fitting & tapped a 5/16 x 18 thread into it (it has about a 3/8" area) attached a threaded rod w/lockdown nut w/a fender washer & used an upside down 1 1/4" socket for the slide hammer portion. I sprayed the area w/Blaster & let it set for 4 days. I used above info & loosened the 10mm nuts that retain the injector & started up the engine. It ran perfect; but then the Injector popped up & fuel started coming out; so I tightened back the 10mm nuts; operated for 45 minutes; It ran like a champ. I did not need the slide hammer; but believe it will work. Now to put on the sales block. A BIG THANKS TO ALL; HOPE ANY INFO I HAVE ADDED WILL HELP YOU.


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## pogobill (Jan 31, 2012)

Glad you were successful!


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## Tater50 (Dec 17, 2011)

I appreciate ALL the help!!!


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## thepumpguysc (Jan 25, 2015)

EVERYTHING on that pump is METRIC..
The line nuts take a 17mm wrench to remove & the thread is a 12mm.. 
Did u TORQUE the holder back down on the pump.?? or just use your wrench to tighten it up? 
I'm glad u got it running.. but I just wanted to clear-up your "misconceptions" for anyone else that stumbles on this..
I hope u get it sold..


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## Tater50 (Dec 17, 2011)

True: My bad; should have said 17mm for 17mm & 11/16ths are very close & everything torqued. The 12mm thread though is not a 1.25, 1.5 or 1.75. I bought ALL the nuts & they only threaded about 1/8th inch. It is like our pipe thread except I think it is British according to my research. I "still" plan to find out exactly what thread it is. My research shows that the Japanese use British Pipe Thread. I will find out; may take awhile. THANKS for the reply. As far as the 955 for sale; I have removed it cause I found a trans front plate at a decent price & I will repair & maybe keep' since I have another deck. Everyone that I have found was $400; "used". 


thepumpguysc said:


> EVERYTHING on that pump is METRIC..
> The line nuts take a 17mm wrench to remove & the thread is a 12mm..
> Did u TORQUE the holder back down on the pump.?? or just use your wrench to tighten it up?
> I'm glad u got it running.. but I just wanted to clear-up your "misconceptions" for anyone else that stumbles on this..
> I hope u get it sold..


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## thepumpguysc (Jan 25, 2015)

I have a pump coming in Monday, I'll put a thread gauge on it & let u know..


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## Tater50 (Dec 17, 2011)

thepumpguysc said:


> I have a pump coming in Monday, I'll put a thread gauge on it & let u know..


Thanks & Also: thanks for ALL your support.


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## Tater50 (Dec 17, 2011)

Thanks for ALL the support: I put the JD up for sale & the first person that came; bought it!!


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## John Gregory White (Jun 6, 2020)

thepumpguysc said:


> Once they're out.. contact me & I'll tell u how to replace JUST the nozzle for 30 some bucks instead of paying 88-90 some dollars for an injector..


Hello, I am thinking of replacing my nozzles on my JD955 as I get some run-on when I shut it down. I was looking on Ebay for some nozzles and found this: https://www.ebay.com/itm/153730433221?ViewItem=&item=153730433221
Would these work or do you know of a good supplier for them?
Thank you,
John


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## John Gregory White (Jun 6, 2020)

thepumpguysc said:


> Once they're out.. contact me & I'll tell u how to replace JUST the nozzle for 30 some bucks instead of paying 88-90 some dollars for an injector..


Hello,
I also have a JD955 and looking to replace the nozzles. Do you have a good supplier to buy from?
Thank you,
John


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## thepumpguysc (Jan 25, 2015)

Take them apart n get the number off the nozzle itself..
Don’t go by the tractor model..
You’ll find them cheaper..


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