Simms Minimec, diesel is getting pump oil.

Sorry meant diesel is getting in pump oil.

After 5 hrs run time the Simms Minimec injection pump oil reservoir on my '64 Super Major was almost 3 ounces over full. I did read that it is normal for diesel find it's way into the lube oil but should it be that fast?

This is a rebuilt pump and I thought I'd ask here for info that I can take back to the rebuilder. I did take it back to them after a few hours use because oil was coming out of the breather and they said there was nothing wrong with it and I thought maybe I had over filled it.

This was a major overhaul and they are a very competent injection pump shop, I'm just curious if there was something they missed of if it is normal for the oil level rise that much? 8 hrs on rebuilt pump so far.

I also asked this over in the ford forum



This post was edited by JLMac on 06/22/2022 at 05:49 pm.

Seems a bit quick to fill, does diesel also run out of the pigtail pipe at the front
of the cam box?

The only way diesel can get into the cam box and through to the mechanical governor, is via the pump plungers which are a
metal to metal, high precision seal. (Think about it, diesel will creep through
rusted bolt threads, now think about how it will creep when under 2300 psi pressure
in the injection pump, the tiniest flaw or wear in the plungers will leak like mad).

Some leakage is allowed to lubricate the cams and bearings but it is only a very
small amount.

I would suspect your diesel shop is not as good as they think they are.

It was leaking out the pigtail after the first 3 hours of use after the rebuild but wasn't after the next 5 hours when I drained the 3 ounce out of it. Maybe the oils level was not high enough this time. I wondered about that too.

I will be taking the injection pump to back. Pretty sure they didn't change barrels and plunger.

Thanks for replying Brian, I was hoping you would.

Most of the parts in your picture are governor parts apart from the springs.

This is just musing, if you are no longer leaking diesel from the pigtail pipe, you
do not have too much of a leak from the plungers. The pigtail is the leak-off from
the pump cam box and the only way for diesel to get into the governors is through
the seal between the two. We always were told to check the governor oil level once a
week and drain off any excess liquid, diesel/oil mix, down to the level, then change
the oil every time the engine oil was changed. I realise this was when the tractor's
were working every day. Some tractors filled the governor in that time others did
not.

I am wondering whether the diesel shop filled the pump cam box with Fusus oil
(injection pump test oil), which is used to test injection pumps on the rig and also
for storage. The cam box, being over full, then leaked that into the governor and
out of the pigtail initially, and once you drained it, the pump has now settled down
to a more normal leak pattern.

This is a possibility, perhaps you should run a few more hours and see what happens
before taking the pump back. If diesel continues to pour from the pigtail and fill
the governor, then you know for certain you have a problem.

Just my thoughts.

Brian

Thank you Brian for that suggestion. I will run it for a few more hours bush hogging (topping) and see what happens. Jeff

You are welcome. If you cannot sort it out I will take it off your hands for scrap
price, I will even pay for it to be shipped over here. :0)

Thanks for the offer, I'll keep an eye on scrap prices lol.

Brian, you were right on. I put another 5 hrs on the tractor over 3 days and checked oil level each day. First day it was maybe 1/8th of an ounce overfull and the next two times nothing extra came out. Thank you for your insight! Jeff



This post was edited by JLMac on 07/14/2022 at 06:11 am.

Shucks!!!!! I am not going to get a beautiful, cheap tractor after all.