2008 Jinma 284 Injector Pump Oil Change

[3RRL]

Loretta finally got around to changing her injector pump oil on her 2008 Jinma 284. It is a good thing to check it frequently and change it once a year or sooner if you wish. Keeps your injector pump in good working order.
Some reminders on how to do it. Refer to the photos below and use a level surface to park the tractor on.
First, remove the fill/breather cap on the top rear of the injector pump. It needs a 13mm open end wrench. I didn't take any photos of it (duh), but it looks like/is a miniature breather cap. It's right behind the accelerator linkage. Be sure to rinse it out with diesel or gas and dry it and don't lose the copper washer(s).



Then get a container to drain the oil out and remove the bottom drain plug where shown in the photo (13mm also). What we did is measure the amount of oil that came out for a reference, since some pumps take different amounts of oil.
After draining, put the drain plug back in and tighten.

Then remove the Bleeder cap with a 12mm wrench or screw driver (it has a slot in the bolt). Some have a little rubber plug on the end. I took hers off to check it out. It is a small banjo type fitting like shown in the pictures below. Leave it out for the time being, as the oil you pour in will go in a little easier.



Then using the amount of oil that came out as a guide, pour that amount of new oil into a small container that you can pour into the fill hole (photo above). We used 30w compressor oil, but you can use motor oil if you prefer. A lot of guys use the same as their engine oil. Anyway, after you get that oil in, screw the bleeder plug back in, but do not tighten yet and leave the rubber cap off. Wait a couple minutes to see it starts dripping from it.



If it does, wait about 15 minutes or so before tightening it up and put on the rubber cap. If it does not, add about 1 oz of oil at a time and wait for it to drip. After it stops dripping, that means the pump is filled to the right level. Then you can tighten it up and put the rubber cap back on. Also reinstall the breather fill cap and tighten it up. We found her Jinma took about 8oz or so.
That's all there is to that. Check the level frequently and change it at least once a year after that.

 

[kennyd]

Maybe I have lived a sheltered life, only having been around International(Ford), Isuzu(GM) a few CAT's and Yanmar(JD) diesel engines...

BUT...

I have NEVER heard of changing injector pump oil

 

[DwayneB]

Maybe I have lived a sheltered life, only having been around International(Ford), Isuzu(GM) a few CAT's and Yanmar(JD) diesel engines...

BUT...

I have NEVER heard of changing injector pump oil

The pumps aren't machined as tight as the name brands. It dilutes with fuel over time. That's why we change it. and oil is cheap.

 

[Harrygoodwrench]

The pumps aren't machined as tight as the name brands. It dilutes with fuel over time. That's why we change it. and oil is cheap.

I change mine every time my oil change interval comes up or at least yearly. Heck, its only 10 ounces max. I've not found any dilution but like I said, 10 ounces of oil is cheap.

 

[Willl]

Maybe I have lived a sheltered life, only having been around International(Ford), Isuzu(GM) a few CAT's and Yanmar(JD) diesel engines...

BUT...

I have NEVER heard of changing injector pump oil

Same here. Is this just a 'Jinma' type of thing ?

 

[kennyd]

The pumps aren't machined as tight as the name brands. It dilutes with fuel over time. That's why we change it. and oil is cheap.

The "Name Brands" DO NOT have a separate oil reserve in them They are lubricated by fuel...That is ULSD is bad for older engines with mechanical fuel injector pumps and a additive should be used to increase "lubricity"

 

[Bob Rooks]

Maybe I have lived a sheltered life, only having been around International(Ford), Isuzu(GM) a few CAT's and Yanmar(JD) diesel engines...

BUT...

I have NEVER heard of changing injector pump oil

Most of the name brand fuel injection pumps (Bosch, Roosa-Master, Stanadyne, Kiki, Lucas, etc.) on the bigger name brand engines will have their lubrication provided by the engine's oil system.

The tolerances in the Chinese pumps are much on par with the other manufacturers. They have to be, because there are no seals of any kind in the barrel and plunger assembly, only the lapped tolerance. The oil in the pump's sump serves to lubricate only the governor (common sump), the fuel transfer pump, the rack, and the pump shaft. The barrel and plunger assemblies get their lubrication from the fuel oil.

 

[3RRL]

Maybe I have lived a sheltered life, only having been around International(Ford), Isuzu(GM) a few CAT's and Yanmar(JD) diesel engines...

BUT...

I have NEVER heard of changing injector pump oil

Kenny,
Yes, we have to do it on our tractors.
It is a recommended procedure to check the injector pump oil regularly and also to change it it at least once a year.
These pumps have their own reservoirs of only 8oz or so. I believe yours may use the engine oil for lubrication (like many tractors) and so every time you change that, the injector pump gets fresh oil too. So you never need to do what we need to do, but in fact it is being done.
My post was directed (of course) at the other Jinma tractor owners which need to do the same, since there is a specific procedure for it unrelated and separate from engine oil changes. It was not intended to be a general information post relative to all tractors, nor does it apply to all.

 

[3RRL]

As an update on the drain plugs on this injector pump, Ronald from Ranch Hand Supply informed me there are two drain plugs. I had asked him where it was with this photo and he told me it was the one labeled "2ND DRAIN PLUG".
He said to drain that also since it lets out a little more oil.

 

[Bob Rooks]

That's the governor. The sumps are in common, so use the lowest one.