Help with hydraulic leak in loader control valve (L4701-HST + LA765)

[Cottonmather0]

I was moving brush piles today with my grapple when my loader control valve sprang a high pressure leak. I am not handy and not good at repairs, so I'd just as soon take it to the dealer, but I need to figure out how to stop this leak in the meantime so I can get it onto the trailer.

Tractor is an L4701-HST with an LA765 loader. I think the valve block is part number YS027.

Can someone tell me:

a.) What is this part called that's leaking? (it literally looks like the end blew off of this thing)

and

b.) Is there some way to easily cut off the hydraulic fluid to the loader?

Pictures are attached and a short video of the leak is at the link.

https://x.com/sheriffj_john/status/1982534990408880208

Thanks in advance for your help.

 

[Russell King]

There may be a “valve” to divert the pump flow. Follow the hose that enters the FEL power in port (usually labeled with a “P” cast into the valve) down to where it connects to the tractor. There may be a block with three hoses connected to it. There may be a screwdriver slot to turn one way or the other (vertical to horizontal maybe). The operator manual should cover it.

Otherwise you can disconnect the power in line from the valve and bypass the FEL valve by connecting the Power in line to the power beyond line (or connect the power in line to where the power beyond line connects (at the point where the PB line connects to the tractor again).

 

[TheOldHokie]

I was moving brush piles today with my grapple when my loader control valve sprang a high pressure leak. I am not handy and not good at repairs, so I'd just as soon take it to the dealer, but I need to figure out how to stop this leak in the meantime so I can get it onto the trailer.

Tractor is an L4701-HST with an LA765 loader. I think the valve block is part number YS027.

Can someone tell me:

a.) What is this part called that's leaking? (it literally looks like the end blew off of this thing)

and

b.) Is there some way to easily cut off the hydraulic fluid to the loader?

Pictures are attached and a short video of the leak is at the link.

https://x.com/sheriffj_john/status/1982534990408880208

Thanks in advance for your help.

That is the spool positioner cover for the float position on the boom spool.

There should be near zero pressure inside that cover. Do you have a backhoe, rear remotes, or 3rd function on the tractor?

Dan

 

[Cottonmather0]

That is the spool positioner cover for the float position on the boom spool.

There should be near zero pressure inside that cover. Do you have a backhoe, rear remotes, or 3rd function on the tractor?

Dan

Yes, i have rear remotes (that have never been used in 7 years) and 3rd function on the loader. The 3rd function is what opens and closes the grapple attachment I was using today.

 

[TheOldHokie]

Yes, i have rear remotes (that have never been used in 7 years) and 3rd function on the loader. The 3rd function is what opens and closes the grapple attachment I was using today.

You need to fix the plumbing - its not correct.

Dan

 

[Cottonmather0]

UPDATE:

I took my photos and my video to the dealer today to get some advice. No one there had ever seen that part blow out (the tech referred to it as a "relief valve" and said it was technically called a "detention plug").

The tech asked if I had overloaded the loader. I described what I was doing - moving large tree trunks with the shredder attached to the back of the tractor as ballast - and he said I very likely overloaded it and that's why it blew out.

He said there was no way on the L4701 to shut off the flow of the fluid because it is considered a "continuous flow system" and the only way to do so is to remove the entire valve block and cover it with a certain metal plate to divert the flow.

That sounded complicated, so I asked if the plug/valve itself could just be replaced and he said, "I've never had to replace one but I don't see why not if the part is available."

We looked up the part number and it was available, so I ordered one (YS020-91500) and it will be here next week. The shop manual says all that is required is to unscrew it with a ratchet, then screw the new one in to the torque specification.

I will report back when I have attempted the repair.