1966 G1000 Wheatland Injector Pump removal

MinniMan

Member
We have a G1000 Wheatland tractor which needs repairs to the injector pump. It is surging when running and from what I have read it has a fiber ring which is failing. The pump is fully operational at the moment but I don't want to damage it before repairs are made.
My question is what is the correct procedure to remove the pump for repairs. Does the engine need to be turned to a certain position so that when replacing the pump it will be in correct time?
I have never removed an injector pump on this tractor so will appreciate all advice.
 
Clean the area around the pump and all the injectors as best you can to keep dirt out.

To keep the pump in time with the engine:

First remove the rectangular cover with the two screws from the side of the pump to expose the timing marks inside the pump.

Then, rotate the engine until the pump timing marks are aligned. It is also a good idea to mark the flywheel just in case the engine should be nudged while working on it.

At that point, the pump can be removed and re-installed with the timing marks aligned and the engine should run as it did before the pump was removed (hopefully without the surging issue).

After installing the pump, all of the injection lines will need to be bleed to remove trapped air.

Not a difficult job.
 
just remove the pump after a wash job. don't make a bit of difference where the marks are. then... when u go to install the pump you get the engine on TDC on #1 cyl. line up the timing marks on the flywheel to factory spec. 705 is 11 degree's not sure if this one is the same. then.. you look in the pump and make sure the dot on the shaft is to the top. then you carefully slide it over the LUBED seals not to fold them. then you line up the timing marks in the pump window by turning the pump and tightening the two bolts.
just lining up pump marks don't tell you where the engine timing was set at , it could have been out of time all along. you need to go through the whole procedure. plus its a good idea to set the valve lash also to make sure you have a good running unit.
 
Thank you Rustred. Additional information is always appreciated. Much easier to have a good understanding BEFORE removing parts because it makes replacing them much easier and more satisfactory. All suggestions and comments are welcome and appreciated.
 
It is always good to verify timing when working with an injection pump or distributor (magneto). I have come across several MMs that have had the flywheel indexed incorrectly over the years and the timing marks are not visible when #1 is at TDC.

That makes timing a diesel more complicated unless you have the head off the engine to determine TDC accurately.
 
Thanks for the heads up SWMolines. Now that would lead to a head scratcher.

The correct procedure would be to remove the front valve cover and make sure the intake valve is just closing on #1 cylinder. Then rotate the crankshaft a 1/2 revolution and hope to find the timing mark in the index window. If it is visible we are ok. If not we have a problem.

Why would the index marks not be positioned in the proper location? Is it possible to install the flywheel in any position on the crankshaft or was it a factory error in marking the timing marks? Usually the flywheel will only install on the crankshaft according to the spacing of the flywheel to crankshaft attaching bolts.
 
Surge may also come from a worn throttle shaft The worn elastoplastic ring bad will cause it to die when put from high speed to idle have a good diesel shop rebuild it for you .
 
The flywheel on G1000s and similar motors can be put on the crank in any of 6 positions (6 bolt pattern) relative to the crankshaft.

Your method of watching the intake valve close + 1/2 turn will get you close. Verifying the timing marks in the pump are aligned should get you spot on. And, as has been already stated, it is always good to verify the timing when re-installing the pump using the marks on the flywheel.

I have had at least one Vista with the timing marks about 120 degrees off from the crank and had to use a measuring tape to re-set the timing after someone else had rebuilt the motor and installed it on the tractor. I was lucky enough to have a fly wheel on the floor that I could get the measurements needed to time the pump.
 
Thanks fossil.

No it doesn't die when idled down from high speed to low speed but rather idles unevenly and even at higher speeds surging. Yes having the pump overhauled is the plan. That is the reason I want to be sure that when I remove it I can replace it with the correct timing.
 
To my knowledge this engine has never been apart so I am thinking the flywheel will be in its original position. Strange that there were no locating dowels or bolt pattern to align the flywheel with the crankshaft. Most I have come across couldn't be installed incorrectly. But never say never. Thanks for the further explanation SWMolines.
 
Just rebuild it yourself. Done several of my own. Don't have test stand but so far batting 1000. Have done the Bosch inline and
rotary also.
 
Dowel pins and bolts for the flywheel are equally spaced. I think it can be installed 8 different ways. Engine did not need to be apart for the flywheel to be off. Typically the flywheel is removed and resurfaced when a clutch is replaced. It more than likely has had a clutch in its lifetime.
 
Hi ChrisQ

What you say is very true the flywheel could have been removed for resurfacing upon a new clutch installation. I suspect being in the 3500 hour range that is quite possible. However, I know this tractor did some field work but spent a lot of its time as a PTO tractor. The drawbar is not worn from pulling implements like one would expect from many hours in the field.

Still, I will proceed with due diligence when checking the timing of the pump before removal. I do appreciate all thoughts and comments since each person shines a new light on issues that could crop up.
 
Hi molinegb

Now you are showing more confidence in me than I have in myself. You have a great deal more experience with the eccentricities of an injection pump than I do. But I do appreciate your vote of confidence.

I am waiting for a warm sunny day so the shop warms up a little before I tie into this project. So far we still seem to be enduring a nasty windy cool week minus the snow our neighbours to the south are getting.
 
check the timing now before you even tear it apart , give you experience and it tells you if it is indeed set to specifications. as it is now running and you cant screw things up , then when ready to install pump its a walk in the park!
 
Hi Rustred

Those were my thoughts too. Check to make sure the timing is set up now then go from there. It starts very well as is so I expect it will be about where it should be already. Its sitting in the shop and no one is likely to touch anything while the pump is off so shouldn't have to worry about anything getting changed. Just have to set #1 at TDC, check for the timing mark on the flywheel and make sure the lines are aligned in the pump behind the little side door and all should be good.

Expect to be looking at about $1000 Cdn. for a rebuild job but the old girl is worth it. Will check the valve clearances once it is back in operation too. Will get a price on injector rebuild as well. Probably would be wise as the pump depends on the injectors to do their job. Son wants to use it for a bit of haying and just a handy yard tractor.
Sorry for the angle of the pic but happens when taken with a cell if you forget to turn it sideways when taking a pic and then want to upload to YT.
mvphoto34324.jpg
 
nice tractor. you set #1 cyl. at TDC on the COMPRESSION stroke. there is TWO TDC's. that's why you watch #6 cyl. when setting the valves. each cyl. has a running mate. when the running mate's valves are rockin , the cyl you want to adjust is on TDC on the compression stroke. handy yard tractor... hummm? give me forty acres an i'll turn this rig around!
 
Hi Rustred

Yes you are totally correct pistons reach TDC twice on four cycle engines.

One time on compression and the second time on exhaust. With #1 on TDC compression #6 will be on TDC exhaust just prior to the intake valve opening if my memory serves me correctly.

Actually the G1000 is an amazingly short turning tractor for it size in its day. We used to have a Massy Ferguson super 95, similar to the MM G6 and that one needed between 40 and 41 acres to turn around. You usually had to make at least three passes for headlands depending on the size of tillage tool you were pulling.
 
Hi molinegb

You are perking my curiosity about your supplier for the kit for the injector pump. Not sure if you can mention a supplier on here but that sounds tantalizing.

On another note:

I think we had an online chat several years ago about an M670. What was the cause of it not wanting to start? I have always been curious to know what the results were on that one. I think it was an LPG originally if memory serves me right.
 
Most pumps like yours I repair, test, and return run 300-400. long as the pump hydraulic head is good. I'd leave the injectors alone too, unless there's a known problem with them. They don't cause as much trouble as most think they do. Just my thoughts of forty plus years and counting of diesel injection repair..
 
Hi Dieseltech

So you are suggesting have the pump repaired and leave the injectors be. Since it will start and run I don't think there is anything broken inside the pump. But we have no plans for running it further until repairs are made since I have read where it can lock up and break a shaft in the pump.

You price sounds reasonable however I am not in the US. So a number of factors come into play, shipping and exchange rate of around 35%. But could still be less than around here. I'm assuming you are in the US of course.

I do have to replace an O-ring where one of the injectors is seeping engine oil. But that is to be expected on a 53 year old tractor.

Thanks for your suggestions as I appreciate all the information you and everyone else has willingly shared.
 
so where in Canada u located Minnie man? I would not touch the injectors if tractor is starting good and runs good. I have taken pumps to GCL injection in Edmonton for my 560.
 

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