Yanmar 165D hydraulic leak and transmission fluid is low.

Bazman72 · Oct 1, 2019

I have a Yanmar 165D with an aftermarket loader (from Coldwater Tractors in WA). It started making a high pitched noise which appears to be in the under the seat/transmission area. I am interpreting this as a likely hydraulic leak noise.

When I had the loader installed they said the hydraulics for it ran off the transmission. I checked the trans fluid level and it's low, at the bottom of the dipstick. It hasn't been checked for a while. I didn't see any fluid leak or puddle under the tractor.

The manual says to use John Deere 303 Hy Gard for the transmission. I don' t know what fluid is in there since I have not changed it since I bought the tractor (3rd hand). Could I add the JD303 and run it while I look for the leak? Could that fluid react badly with whatever is in there (probably JD303 since the previous owner seemed meticulous)?

Any recommendations for a tractor rookie with a problem?

Thanks!

RNeumann · Oct 1, 2019

Getting the fluid to the proper level would be a good start. I’d use the recommend fluid until you can research some alternatives- I’m sure their are several.

Roadworthy · Oct 1, 2019

Top up your fluid as suggested. Look for leaks at the new hydraulic connections. A hose may seem tight upon installation but after running a bit the parts may kind of size themselves and need retightened. Use two wrenches to avoid twisting lines.

nyone · Oct 2, 2019

Most manufacures state 1,000hrs between hydraulic oil changes. If your close it may be worth just draining it all.

303 hyguard is a oil for wet clutches/brakes. Most any Universal Tractor Fluid is good for wet clutches/brakes. You still should find out what weight oil it takes.

Bazman72 · Oct 2, 2019

Thanks. I refilled with John Deere Hy Gard. Will try it out and see.

Bazman72 · Oct 2, 2019

Thanks. I tightened everything.

rScotty · Oct 2, 2019

Bazman72 said:
I have a Yanmar 165D with an aftermarket loader (from Coldwater Tractors in WA). It started making a high pitched noise which appears to be in the under the seat/transmission area. I am interpreting this as a likely hydraulic leak noise.

When I had the loader installed they said the hydraulics for it ran off the transmission. I checked the trans fluid level and it's low, at the bottom of the dipstick. It hasn't been checked for a while. I didn't see any fluid leak or puddle under the tractor.

The manual says to use John Deere 303 Hy Gard for the transmission. I don' t know what fluid is in there since I have not changed it since I bought the tractor (3rd hand). Could I add the JD303 and run it while I look for the leak? Could that fluid react badly with whatever is in there (probably JD303 since the previous owner seemed meticulous)?

Any recommendations for a tractor rookie with a problem?

Thanks!

The noise is probably the hydraulic pump starving for fluid. It could be low fluid or it could be the hydraulic filter. Or in this case, both.

On the YM165D you have a cleanable hydraulic filter in the transmission that definitely needs attention. It is a long screen beneath a three bolt flange and located approxi. under and behind your right foot. Most Yanmars had that filter. Early ones used stainless steel mesh and later ones a polyplastic mesh. Clean with a soft brush and soapy water. You can make up a gasket - the thickness is not critical as long as it doesn't leak. If you don't clean that filter it will clog up over time and will starve the hydraulic pump. This is normal maintenance for the YM165D. I would try to get a shop and parts manual if you plan to keep the tractor. It's worth keeping. they are a good little tractor and will last a lifetime.

Yes, fill to the mark withany trans-hydraulic fluid. JD303 is not made anymore - it hasn't been made for years. It was a popular brand for decades, and that is the reason you will see other brands saying that their oil meets JD303 specs. That's not possible, since JD303 was a brand, not a spec. It's just adv. hype. There has even been agriculture-based legislation over about that. You can find info online.

The YM165D was made with a very simple and robust transmission and hydraulic pump. There are no critical oil-wetted components or elastomers (seals) that require JD303. It will do just fine with any of today's trans/hydraulic oils. But you have to clean that filter to allow the oil to flow.

BTW, there is a Vintage Yanmar forum here on TractorByNet. Lots of information there, as well as other Yanmar YM155/165 owners.
good tractoring,
rScotty

rScotty · Oct 2, 2019

Here's some literature for your YM165D.

It was possible to run a loader -slowly - using nothing but the 165's internal hydraulics, but most used a small accessory hydraulic pump driven off the front of the crankshaft. That can be changed at any time, and it allows the loader hydraulics to be completely isolated from the tractor hydraulics.

The best loaders for any of these small tractors is one that has a subframe that runs from the front frame of the tractor all the way to the rear.... and ends up bolting to the heavy metal - in this case around the transmission case where the rear axles come out. Today, no loaders that I have seen are being made without that subframe, but a few decades back a few light duty ones were.

rScotty

Bazman72 · Oct 2, 2019

Thanks. My loader has a subframe.

rScotty · Oct 3, 2019

Bazman72 said:
Thanks. My loader has a subframe.

That's excellent news about the subframe. ! I'm so glad to hear it! Subframes are always a tough subject to bring up because of the history of what happened without them, but it is important.

There were two ways Yanmar used to power the loader. The inexpensive way used the tractor hydraulics and a special Yanmar part that mounted on top of the transmission case to re-routed hi pressure hydraulic flow to both the 3pt and to the loader. That part was just a block of aluminum about an inch thick and maybe two by 3 inches with threads for hydraulic fittings. The block cost about $30. And the hoses another $100. I used to have one of those blocks kicking around in the shop here.

Yanmar also offered an upgraded way to power the loader which was an accessory pump driven off the front of the engine crankshaft. It was faster and didn't interfere with 3pt ops, but cost about an additional $6/800 at the time. I have the installation sheets on this, I think. You may notice High prices never did seem to bother Yanmar - only high quality counted. That sometimes caused my dealer friend to pull his hair out in frustration.

Yes, Yanmars were costly. No way around it. A new Yanmar YM165D - or any Yanmar model - could easily cost 30/40% more than another brand of compact tractors back in the 1970s. And since Yanmar offered more options, it only went up from there. Of course the others are now gone and the Yanmars are famous for still running and doing work just as always.... But how something will run 40 or 50 years later does make for a tough selling point when new.

If you need info on the hydraulics or cleaning that filter just post here or in the Yanmar forum. Cleaning the filter is not obvious. It is a suction type,(not pressure filter), and that does make it easier to service. Treat it carefully and it will last through many cleanings. The screen itself is 200 mesh S.S. so making or patching one is also possible.
I'm about to post some old Yanmar 3pt lifting specs in the vintage Yanmar forum if you are interested.
rScotty