YM240D Bucket slow till 3pt hitch engaged

[braeges]

I've read the posts and am about to purchase my first compact tractor. I've located a YM240D at a local dealer witha good price. Here's my concern/question: The bucket moves up and down slowly until you engage the 3 point hitch control in the same direction as you want the bucket to go. A new valve was recently installed for the bucket. I am able to lift the front end of the tractor up with the bucket so I believe the hydraulic pressure is good. Is this normal for a Yanmar? or am I and the dealer doing it wrong? Thanks

 

[normde2001]

I'm not sure what your question is, but there are too many variables with a loader to answer. It mostly depends on how it is installed, and condition. Normally the 3ph and loader are not operated simultaneously.

 

[braeges]

Thanks for the input. I'm going back to the dealer this afternoon and attempt to find the exact sequence that is required to "speed up" the loader. The new valve for the loader was just installed by the dealer (JD) prior to the trade in. I cannot find a good diagram of the Hydraulic system for this tractor in order to get an idea why it needs the 3PH engaged in order for the bucket to operate beypond a "slow crawl". My question really is, is there some type of diverter valve in this tractor which need to be opened or closed in order to operate the 3PH and bucket independantly?

 

[normde2001]

You won't find a hydraulic diagram, as the loader is a user add-on and not OEM. No diverter valve, the loader should be plumbed in series so all fluid is either used by the loader, or goes straight to the 3ph, such as this:
http://www.hoyetractor.com/loaderinstall.htm

 

[California]

My YM240 has a loader that I think was dealer-installed when new. It acts something like you described.

There are various combinations of loader motion and 3-point operation that interact. This is logical since they are plumbed in series.

In particular leaving the loader in 'float' while driving with something heavy on the 3-point will cause an empty bucket to raise. What is happening is the 3 point piston is bleeding down pushing fluid through the open float position in the loader's controller. The pump will usually keep up with it so the rear implement doesn't drop. I have encountered this several times when I wanted to back-drag to fill in and level an excavation. I'm looking to the rear as I back up, expecting to drag the bucket over the rough ground to level it. Instead I stop when I hear a crunch, look forward, and see I've snagged a limb of an orchard tree with the fully raised bucket. The loader control is still in float position.

The only way to have float available with the backhoe installed is to close the valve under the front of the seat so the 3-point's return path is choked off.

I think the slow speed you see is limited by the relatively small pump. (My YM240 was apparently ordered loader-ready, with an optional hd front axle and apparently the optional pump). When you see faster motion on the loader, that is probably the 3-point descending and adding its volume to the pump's volume.

Not a bug, just a feature.

Added, after thinking about this some more:

The bucket moves up and down slowly until you engage the 3 point hitch control in the same direction as you want the bucket to go.

Mine doesn't do that. If both are engaged in the same direction, whichever one has less load moves while the other stalls or descends. It feels like engaging a second simultaneous motion causes a huge leak in the circuit that is feeding the first motion.

This is true of the separate lift/control levers for the loader, as well as for the 3-point combined with either.

Another thought - 'regenerative' is an optional feature that routes fluid returned from a retracting cylinder, toward the other end of the cylinder that can use this extra volume to move faster. I don't know much about it, but it might be relevant to what you see.

 

[JL Sargent]

Your tractors 3pt is controlled by an "open center" valve. So when the valve is in the float position (no working being done) then fluid simply passes through the valve and is returned to the hydraulic tank. When work is being done the fluid passes through that same valve (a slightly different way) and returns to the tank.

The loaders valve is typically daisy chained between the tractors valve and the tank with another "open center" valve. So when valves and cylinders are working properly (not leaking) there should be NO cross affect if one of the two is in float position. Now calling for work from both valves certainly could create a temporary increase in pressure/flow I guess, but only while a heavily loaded cylinder(s) bleeds down.

The OP is most likely experiencing typical loader speed. California on the other hand probably has a leak or two.

 

[braeges]

Thanks everyone. I took a good look at the system and indeed it is in series. the loader's hydaulic fluid is tapped off the "top" of the tank and appears to have been that way for a long time. Everything works fine, just a bit unusual. I am waiting for the delivery this morning. I'll post pictures and an update after I run it for a little while and get some much needed work done around here.

 

[normde2001]

What "tank" are you referring to? The only tank should be the transmission.

 

[JL Sargent]

Tank = hydraulic reservoir (IE: wherever the tractor's fluid is stored.:thumbsup
Actually on a Yanmar isn't it the back 1/2 of the tractor?

 

[normde2001]

Yes, but I was referring to this: " the loader's hydaulic fluid is tapped off the "top" of the tank and appears to have been that way for a long time."