Yanmar YFL-240 Loader Hydraulics

haze5736 · Feb 10, 2021

I just purchased a Yanmar YM240D with a YFL-240 Loader and have some questions as I'm new to tractors and hydraulics.

First, does anyone know where I can get the manual for the loader? I've searched and have found nothing.

I have a couple of very slow leaks I want to deal with. First is the controls. I get about a drop a day of fluid coming off the controls. Is there a typical problem that would cause this, like a gasket or o-ring?

The biggest question I have at this point is, how do I safely open the system? If I want to disconnect one or more lines from the control valve, do I first need to relieve the fluid pressure? If so, how?

Once I get to the point of removing a line, will hydraulic fluid flow out until it gets to a point lower than the hose?

bmaverick · Mar 3, 2021

haze5736 said:
I just purchased a Yanmar YM240D with a YFL-240 Loader and have some questions as I'm new to tractors and hydraulics.

First, does anyone know where I can get the manual for the loader? I've searched and have found nothing.

I have a couple of very slow leaks I want to deal with. First is the controls. I get about a drop a day of fluid coming off the controls. Is there a typical problem that would cause this, like a gasket or o-ring?

The biggest question I have at this point is, how do I safely open the system? If I want to disconnect one or more lines from the control valve, do I first need to relieve the fluid pressure? If so, how?

Once I get to the point of removing a line, will hydraulic fluid flow out until it gets to a point lower than the hose?

You need to find this one. Sorry, I only have the front cover.

California · Mar 3, 2021

And - come join in the Yanmar [classic] subforum here. Other YM240 owners are more likely to see your question there.

I have a YM240 with a dealer-installed Great Bend loader (photo), likely similar to the Johnson (American made) loader you have. I replaced a controller that dribbled when under extreme pressure, and I've replaced a few cylinder seals. Everything is simple and obvious, you don't need a manual.

California · Mar 3, 2021

haze5736 said:
...
I have a couple of very slow leaks I want to deal with. First is the controls. I get about a drop a day of fluid coming off the controls. Is there a typical problem that would cause this, like a gasket or o-ring?

The biggest question I have at this point is, how do I safely open the system? If I want to disconnect one or more lines from the control valve, do I first need to relieve the fluid pressure? If so, how?

Once I get to the point of removing a line, will hydraulic fluid flow out until it gets to a point lower than the hose?

As for your specific questions:

* a drop a day? its 40 years old. Just live with it. The handles move pistons that are a precision machined fit without o-rings, so not repairable. But verify that's where it leaks. Everything else should be simple o-rings or gaskets, or a leaky hose, easy to fix. ($25 ~ $50 per hose made up custom for you at your local hydraulics shop). If your cylinder seals leak excessively, more than just sweat, most types are easy to replace. Take a photo and ask here in Hydraulics or in Yanmar for advice. I had to get a jumbo pipe wrench then add a cheater pipe for 5 ft of leverage to unscrew end caps. Aside from that brute force everything was simple and obvious.

Realistically, budget some $300 if you feel a need to replace the control. I did, after it dribbled on my shoe while lifting a 650 lb water tank.

* Safety - Engine off, wiggle all controls to maximum in all directions. This relieves pressure so it's then safe to open a line.

* Hydraulic fluid drain - have a coffee can ready for the contents of the hose to dribble a little. That's all.

haze5736 · Mar 16, 2021

Thanks for the tips. It's winter and I was bored so I decided to open up the control valve to have a look. I replaced the 4 o-rings that sit in the grooves of the housing at the ends of each valve. It was a couple of bucks for the bag of o-rings and now i have a few spares. That seems to have solved my leaking valve problem. But, for how long we'll see. The ends of the valves or pistons or whatever they are called on the lever side have some pitting that appears will ride over the new o-rings. I'm not sure if that will shorten the life of the new o-rings. If I get at least 2-3 years out of them I'll probably keep replacing them since it was easy enough. If I have to do it again I will probably leave the valve on the machine with all the hoses connected.

The only other issue I see with the control valve is the end of the lever, where it contacts the valve is pretty worn giving a ton of slop. I can probably weld some metal on there and shape it back to a better fit. Not sure if it is worth the hassle, but sometimes winter boredom kicks in. And I need to figure out a fix for the torn boots around the levers. The best recommendation I've seen so far is to use bicycle inner tubes and clamps. That sounds like a good enough solution to me.