How to Change the Oil in your Yanmar 155D Tractor

After serving me well all summer, I wanted to finally give back to the tractor a little TLC and learn a bit more about her. I suppose many people treat their cars the same way I treated the tractor – only wanting to know enough to make them go, and assuming you could get someone else to deal with any other problems. My problem with that strategy was that if something went wrong with the tractor, it was going to be a big deal to find a way to get it to someone to look at it. I don’t have a trailer for transporting it – and I planned on taking it deep into the bush where problems may have to be solved on site.

So with that in mind, I decided to tackle the most basic of maintenance – the oil change. I hit up the great boards at After a bit of backing and forthing, I had a recommendation to add almost seven quarts of oil, and another recommendation for what sort of oil filter I needed. After a bit of head scratching at Canadian Tire, I simply googled Napa 1064 to get a FRAM 8393A. I also picked up ten litres of diesel motor oil.

Yesterday I emptied out a rubbermaid tub (thank goodness I have a couple dozen of them from the move), and drained the inky black oil into it. There was shockingly little! As it drained, I used my time to connect some battery testing clips to the ends of my winch wires. This allowed me to connect the winch directly to a separate battery, which I will simply charge up using either my generator or the solar panel system at the end of a skidding session. We’ll see how long the battery can last next time I get a chance to winch. I want to wait for the ground to freeze up again so I don’t tear up my laneways too much.

Then I also tackled the broken connector on the winch where the controller enters the solenoid – I had foolishly moved the tractor once with the controller still plugged in, and running over the control cable broke the connection off right at the controller. I beefed it up by bolting a large washer over the entire connector, with just the shaft sticking through the hole in the washer.





After the oil stopped dripping, I replaced the drain plug (directly underneath the engine, facing straight down, starboard side of the tractor – under the dipstick), I opened up the oil cap on top of the engine, and poured in my first five litres bottle. On a whim, I pulled the dipstick and was surprised to see oil right up to the collar on the dipstick! I replaced it and came back to the yurts to consult the service manual for the tractor. After much squinting at the small print, I found an entry that suggested two litres of oil – I suppose I should have read the manual before asking well-meaning strangers for advice :). Mea culpa.

I returned to the tractor and was able to messily pull the plug again, but I drained this oil back into the jug for future use. I think because it was just in the engine and right back out again it shouldn’t be in bad shape.

After checking it over a bunch with the dipstick and plug, I finally got the oil down to “totally full” and called it a successful venture.

Replacing the oil filter on the port side of the tractor did involve me having to remove a small screen with three, ten millimetre bolts. It was too tight to turn off by hand, and with the screen there I couldn’t get my filter wrench any purchase. The gasket from the filter was left behind; I had to take it off with my fingernail. I lightly greased the gasket on the new filter and hand tightened it down. I check with my filter wrench, and it seems that the Fram filter is marginally smaller than the previous Kubota one, so I’m not sure if my wrench can get good purchase on it to remove it – hopefully I didn’t screw it down too hard.

I turned the engine over and let it idle a few minutes. The oil pressure gauge read about 60psi – I don’t know if that’s good or not, but I know oil is in there, so that’s my baseline. It’s also what it has always read.

I then started looking at the rats nest of wiring on the machine. I removed a bunch of wiring relating to two sets of lights (non functioning). I then removed the varied switches that related to those lights. I don’t plan on running the tractor after dark if I can help it. If I find I need to, I’ll add lights back on at that time.

I also realized that the one idiot light that had stopped working was simply due to a dead bulb – I removed the bulb from the oil pressure gauge as a previous owner had simply cut the wires to it. This caused both my idiot lights to come on, as I was use to. After a bit more fiddling, the OTHER idiot light went out. I’m not sure what that says about my abilities. Following the wires around, I can see that the first light only seems to go to the ignition, so that’s not very useful – I suppose it can remind me if the key is turned but the engine is not running. The second light goes to a sensor on the upper, front, port side of the tractor. I suppose it is either a temperature or oil pressure gauge, but I don’t know which yet. I’ll consult the service manual and see if perhaps it can shed some light on that. Looking in the radiator, I can see the fluid is high, and cloudy. At fifteen below it looked fine, so I’m not sure if I need to change it promptly or not.

Sadly the tachometer stopped working a month or two ago. I wiggled the cable, but it didn’t make a difference. That’s something else to look at if I want it fixed I guess.

The decompression lever was just a rod poking out from under the hood – hard to grip with gloves on. I removed it, and using the bucket of the tractor, put a kink in the end. Voila! It looks like it was designed that way – now it’s very easy to pull the lever to start the tractor!

The PTO on this tractor was totally exposed and it wasn’t a few times that I engaged it while climbing out of the seat. This is a bit too dangerous for me. I found that a Golden Wedding whiskey bottle made a great shroud for it. It fits perfectly snug. I’ll have to add some other way of holding it in place just to be sure, but it’s better than nothing!

Now with all that under my belt, I’m feeling a bit more confident about my abilities to keep the tractor running for me.


5 thoughts on “How to Change the Oil in your Yanmar 155D Tractor”

  1. have had a yanmar 155d for several years now, and have never changed the oil. Went to do that and I cannot see how I c can access the drain plug. The front end loader frame bolts on right in front of the drain plug (below the dipstick). I can feel it behind the steel plate of the loader frame. Short of taking those bolts off both sides and dropping the loader off, I can see no way to accomplish this……….any ideas?

  2. Are you sure that's the drain plug? I know on mine I believe it was on the bottom of the tractor facing down. They did make different variants though, so maybe your is different from mine?


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