Testing / Replacing Injector

[britinusa]

Ron, is this the article you referred to?
http://c34.org/mainsheet/pdf/11-99_Technotes.pdf

Paul

[Stu Jackson]

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Is there an index that would narrow down the subject?

Paul, Ron has, literally, "written it all."  But he doesn't provide links  .  So what I did is described completely in excruciating detail in the sticky "Too Much Information."  You use the Knowldegebase, which is a XLS spreadsheet the late former Commodore Jon Schneider and I cooked up and he maintained for a while.  While it doesn't have everything (i.e., Tech Notes since he passed away) up to date, for say the past 5 - 7 years, it has most of the great "legacy" material.  It's easy to search if you use the correct tab on the bottom (ctrl-F).  I downloaded it years ago to my computer and use it to find stuff for folks.  If you need more guidance on how to find and use it, please let me know.

[Stu Jackson]

Paul,

I just set up two older topics (Guide and Knowledgebase) as stickies so you can find the Knowledgebase faster.  It's a link to the tech notes with the XLS spreadsheet to download.  You could have gotten to those older topics through the "Too Much Info" topic, but this should make it easier for you.

[patrice]

When I replaced my injectors I had to remove the valve cover, otherwise there wasn't enough room for the socket wrench to fit over the injector base. The wall of the socket was too wide. Probably could have found a thinner walled socket, but rather than run out again to the stores looking, I just took the valve cover off.
I also found a pile of carbon dust under each injector after removing them. I assume it fell off the injectors when I took them out. I vacuumed the dust out. So having a vacuum handy when you start the project might save some annoyance.
Regards,
Ed

Hi Ed,
When you did the job, and had to remove the valve cover, was the gasket still good, or did you already had it planned and had a new gasket in hand.

[Ed Shankle]

Patrice,
I reused the "gasket" since it was really an O ring. No subsequent leaking.
Regards,
Ed

[KWKloeber]

When I pulled my cover, I replaced the gasket -- "just because"

It isn't like a typical valve cover that's thru-gasket bolted around the perimeter. 
It may have been okay, but with the Kubota setup I asked myself, "Is the minimal cost worth taking the chance?"

kk

[Ron Hill]

Guys: There is no reason to replace the "gasket" on the valve cover each time you remove the cover.

Reason - the "gasket" is really a square "O ring" that seats in a race in bottom edge of the valve cover!!  Just make sure that where the "O" ring seats on the head that it's free of oil and you've cleaned (wiped) the oil off the "O" ring itself; when you put the valve cover back on.  The "O ring" extends just outside the race so it compresses to seal when the cover is replaced and the retaining nuts tightened. 

I probably have removed that valve cover on an M25XP 10 times - adjusting the valves/cleaning the sponge filter to the breather/
etc. etc. NEVER had a leak with using the same "O ring gasket". 

I wrote this up in the Mainsheet tech Note back in the early 1990s!!

A few thoughts   

[Ron Hill]

Guys : I also need to point out that the valve cover is made out of "pot metal" and does not need or should not be over tightened!

Word of caution -- thought

[patrice]

Hi,
thanks for the info.
Did not know it was O ring.  Tought it was paper type gasket.

[britinusa]

Update on injector change out progress.

'Tommy' from the Kubota store 10mins from our house, had shown me the process to replace the injectors. Included in his instruction (which took place standing next to a display kubota 3 pot engine) was the clear and definite instruction - Do not disturb the hex nut that sits directly on top of the Injector pump. (The one with the plastic cap on the left of the attached pic)

I was able to undo the one tube nut (obviously it's the missing tube) but the other two tube nuts are sized to the tubes and multiple doses of PB Blaster did nothing to help. Both the mid and aft tube nuts are seized to the injector pump hex fittings) So they are unreliable and I'm replacing them.

Returning to the Kubota shop, 'Tommy', and he has been really helpful, provided me with the breakdown of the pump and thus explained why those lower hex nuts should not be removed. The consequence of the engineering parts inside being disturbed would result in either needing a new pump or the pump be taken to a shop for rebuild. So I'm taking great care not to move those lower 'nuts'.

Sharing this just in case anyone else has a similar issue of the tube nuts being siezed. It's my intent to replace all 3 tubes (total cost is only $69.00)

Paul

[Ron Hill]

Paul : Tommy is correct and there is no need to remove the fuel tubes from the injection pump to change out an injector.  I believe I said that in my article!!
Just loosen the nut on the top of the injector and bend the tubes aside to get a socket on the injectors.

FYI, I also wrote an article on changing out the injection pump for the Mainsheet Tech Notes!!

A few thoughts

[britinusa]

Thanks Ron,
I can see bending the tubes would work although that's quite a bend in order to get the injectors out.

New tubes will go in tomorrow.


Paul

[Ron Hill]

Paul : The bending was easy and not really that hard to do. 
Replaced the injectors 3 or 4 times in 5,000 hrs. and Once for the injection pump rebuild!!

A thought

[britinusa]

Installed the new tubes to the Delivery Valve Holder (DVH) (The hex fitting that that the tube connects to at the Injection pump end of the tube)

I used one (of several) cans of compressed air to keep the work area clean and free of gold/blue paint chips and any dust around.

To remove the siezed tubes (Aft & Center) I used a wood chisel as a wedge between the DVH's in order to prevent the one being worked on from turning. That worked fine.

Problem - There is a fuel leak where the DVH screws into the top of the Injection pump housing. DRAT! That's the part that Tommy said ' Don't remove that part'.

Now I feel I have no choice. Looking at the Injection Pump Component Parts diagram (from Tommy) I'm guessing the problem is that the O-ring that seems to create the seal between the DVH and the Injector pump body needs to be replaced. It's part number is 14611-5120-0

Researching.
Any input would be most welcome.

Paul

[KWKloeber]

What does Tommy say?  He's the expert to rely on. The rest of us are just informed amateurs