Possible to regulate 3pt hitch lift rate? (YM186d)

[JCByrd24]

Mine has the remote port as well for a single acting cylinder. Unless I'm thinking about this wrong though, you get no relief protection for your remote cylinder. This could easily break the cylinder or pump at max travel. It seems to me a better design would have been stop valve as the very last thing before the 3PH cylinder. The remote port just upstream of the stop, then the relief connection.

It seems we have this:

pressure in>---tee to remote plug---stop valve---tee to relief----3PH cylinder

When this would have been better:

pressure in>---tee to relief-----tee to remote plug----stop valve----3PH cylinder


The valve I posted is about $80 at surplus center.

 

[winston1]

Well, I'm convinced you probably know a lot more about hydraulics than I do, but, I'm still thinking Yanmar engineers have some explainable reasoning as to why it is designed that way. Still will be interested if you go forward with installing a flow valve.

 

[JCByrd24]

I'm still thinking Yanmar engineers have some explainable reasoning as to why it is designed that way.

Yeah, me too, just trying to figure it out. I'll definitely let you all know if I plumb a flow control valve. I was out just this morning messing around and boy is it fast.

 

[JCByrd24]

All, just an update, figured some stuff out in trying to solve my ballast block lifting issue. I plumbed a gauge into the remote port and did some testing. On my 186D the relief valve does protect the remote cylinder port and also there is no danger to the pump even with the stop valve closed. This might be totally different on grey market tractors. The plumbing seems to be very logical (like the second option I show a couple posts up). The stop valve can be closed with the tractor running and nothing will happen if the 3PH lift lever is in neatral. Try to raise, and pressure raises enough to pop the relief valve, makes the exact same noise if you try to lift something too have, which apparently my 650lb ballast block is when it's setting on the ground. According to the manual it has a 920lb lift capcity....

 

[Buppie]

Disregard the Operation Manual's hydraulic lift capacity of 926 lbs. There are many inconsistencies in these translated manuals (import and gray). The Service Manual is the better guide and it is correct that 550 lbs. is all the three point will lift no further than 24". If your block is beyond the 24" limit (which it must be as only a vertical slab could stay at 24") the hitch won't do it . I made a steel box that weighs 75 lbs. and use 2-150 lb. cast iron wheel weights in the box. I have the same loader as you and found using two additional 100 lb. weights could be lifted but in the cold the pump needed extra warm up time. I can usually lift all the dirt etc. the loader can handle with 375 lbs. and add 100 when needed.

 

[rScotty]

Hi guys, new here, just bought a 186D two weeks ago. Loving it so far. I've noticed the exact same thing, very hard to regulate the up speed with the detented valve. Very fast and jerky when running at rated speed. I've been on a mission to try to figure out the whole hydraulics system after reading about the pump failures due to deadheading and this is also on the list of little things to figure out. .

Congratulations on your tractor. That's one of my favorite motors ever. BTW, Yanmar published an excellent workshop manual for the 186 & 187. In fact, the original factory workshop manuals for the US model 3 cylinder Yanmars just might be the best workshop manuals ever. Good printing on quality paper, too. The hydraulics section is particularly good. If you can find one of the original looseleaf types in the red plastic covers you'll not regret it. Get the parts manual too if you can. Good exploded views and a history of upgrades.

On "full rated speed"....Perhaps you are talking about max RPM? If so, then I think you will find that all of the hydraulic systems are jerky at max RPM. That includes the 3pt, loader, power shifting, and power steering (if installed). After all, this isn't a constant RPM diesel. The tractor was designed to do most of its work at a third to half of full RPM. That is why it has a foot throttle and why it is listed by Yanmar as a "variable speed diesel".

The standard relief valve system as designed should be pretty much foolproof at preventing the pump from deadheading. I haven't followed Yanmar so much lately, but when the US Yanmar tractors were in their first decade or two I don't recall ever hearing of any particular pump problem. I agree that deadheading is a sure way to break something, but it must be harder to accomplish than I thought because it rarely happened. Most common cause of hydraulic weirdness seemed to be when someone had plumbed their aftermarket loader wrong. But even then it rarely broke anything.
Enjoy, rScotty