YM 1500 Stop Valve

[rickcee]

I purchased a ym1500 a few weeks ago and so far its been great. My question is all forums and manuals (bought a shop manual) I've read say my tractor should have a stop valve (the round knob). It does NOT have one! It does have the lever that adjusts the drop speed. Anyone know if the 1500 ever came without a stop valve?

 

[normde2001]

item 68

 

[rickcee]

Yes that is what I'm talking about but it is not there. I think there is a cap at that location. I'm at work now but will take a pic of my tractor this afternoon to post.

 

[clemsonfor]

It could have been lost and someone put a plug in it or something? Its not a necessary item as long as its open. It will just make it harder to trouble shoot some things in the future. If your wanting to service it, i would just lift it and set it down on something like blocks or treestump, i would not trust just the stop valve anyway to climp under a 350-400lb bushhog.

 

[rickcee]

Yeah thats what I was thinking also. Someone may have plugged it. The problem I'm having is with the bush hog. If I lower it all the way down it will dig in, so I try to set it at the proper level with the lift, and without the stop valve it will either drift up or down. I constantly have to adjust it while I'm bush hogging. Any suggestions?

 

[normde2001]

That's not what the stop valve is for. If you run the tractor with the stop valve closed you can ruin your pump. See items 64-67 , or get a set of check chains.

 

[winston1]

I believe you can run the lift locked in with stop valve as long as you do not pull lift handle up after locking in.

 

[clemsonfor]

I believe you can run the lift locked in with stop valve as long as you do not pull lift handle up after locking in.

Maybe but i would not try it. With all this vauge translated info, but i think my english 240 maual says what norm says.

You should have a thumb srew tab on your lift handle that will keep the lift handle into a certain position to hold an implement at that height. This assumes that yours is like mine and that the vibration causes it to lower with the vibrations. Other wise it slowly leaks down and this will not help you should have to keep pulling and resetting, although that would have to be a big leak as these things have a feedback rod system that we have covered a lot on here that senses the lift leaking down and the valve will keep the lift in the position that it is set in. Leak does not matter if your valve is working correctly as it will allow as much fluid in as leakes out of it at the same time. You may have a problem in your valve assembly under the seat.

If you dont have the thumb screw like i talk about you can fix it with a like wing nut and screw and put it in the channel of your lift lever to keep the handle from physically vibrating down.

 

[rickcee]

Thanks for the info guys. I do have the thumb screw but have not tried to use it. I assumed if I left the lever in one position it would stay put. It is probably nothing more than operator error. Because some times it would leak down and other times I would look back and the bush hog would be 2' in the air.

 

[winston1]

I'm not making a recommendation, just taking info from 220/226 book. Page 270-05-6 "A slow return @ stop valve is located in hydraulic cylinder head. It controls the rate of oil flow returning from the hydraulic cylinder to reservoir and by turning the knob in clockwise completely until it gets stopping, hydraulic cylinder can be shut off from the hydraulic system.
By turning the knob in anticlockwise, the valve starts opening and allows faster oil returning flow to make the faster lowering of lift arm.
The stop valve may be used to hold the lift arms in an up position by setting the lift arms to the position then turning the stop valve in. The oil in the hydraulic cylinder is trapped between the piston and stop valve. This trapped oil holds the lift arms in position."
I just completed installation of a 3 point cement mixer on my 2002d. This mixer has a single acting cylinder that pivots the mixer up and down. On the left side (sitting on seat left) of the stop valve body there is a removable plug that allows you to operate a remote single acting cylinder. I installed a quick disconnect at that point. I now raise the mixer to desired height, close stop valve and three point handle then operates single acting cylinder. I didn't just come up with this idea, it is in the same manual.

 

[careyo63]

I wouldn't use the tractor with the valve shut either. Some friends ym2500 refurbished only a few months old started leaking at the pump sure enough someone shut the valve. Lucky all I had to do was tighten the lines on the pump up.
Here is a pic of the yanmar adj. stop for your lift handle Clemson was referring to. I also had to replace the spring and washer on the handle also. PMO when it would still lower when it was not on the stop and found my linkage had alot of play in it so I just had to snug up the spring alittle.
Been almost 3 yrs now with no problems.:thumbsup:

Carey

 

[normde2001]

""A slow return @ stop valve is located in hydraulic cylinder head. "

What does that mean? It sounds as if that manual is referring to a single multifunction valve.

 

[winston1]

Norm, I typed that word for word out of the manual. In my opinion it is a multipurpose valve. It states it can stop the lift or slow or faster drop speed. I have use mine for slowing drop speed for 3 years. I am careful not to close valve, however, if I slow drop speed I can tell no difference in the lift speed or pull on the pump. As I stated in my earlier post it can also be used in conjunction with a single acting cylinder.

 

[clemsonfor]

A big problem you see in some of this stuff is whats lost in translation. Your guess is as good as mine to what that means, if you fully understand hydraulics and how its plumbeb and feel comfortable doing what you are fine. I have a rudeamentary knowlege of them from looking at it and reading about them so i take others words on this.

 

[normde2001]

Norm, I typed that word for word out of the manual. In my opinion it is a multipurpose valve. It states it can stop the lift or slow or faster drop speed. I have use mine for slowing drop speed for 3 years. I am careful not to close valve, however, if I slow drop speed I can tell no difference in the lift speed or pull on the pump. As I stated in my earlier post it can also be used in conjunction with a single acting cylinder.

I suspect that a multifunction valve would work entirely different than a separate "servicing stop" and "slow return" valve. I don't have my tractor or manual handy, but mine squeals when operating the tractor with the valve partly closed. I'm pretty sure it would dead-head the pump.