Leaky Control Valve

[TORQUIN]

So, my 20 year old L3830's 4N1 control valve is now leaking. I disconnected the hoses last night and the clam hasn't moved an inch, so I feel sure it's the valve. I need to find a repair kit, if they are offered, as I suspect replacing the O-rings will fix it, since the manufacturer says the valve will last for 30 million cycles if treated right.
It's a Hyvair, Model D03S-2c-12D-35. The Hyvair web site has been no help. Anyone have any ideas on where I might source a repair kit for it, or can I use generic o-rings that are the correct size?

Thanks,
Chris

 

[oldnslo]

Most hydraulic valves are metal to metal seal so there are no O-rings to replace to prevent cylinder from drifting.

 

[SilentJ]

most manufacturers of hydraulic components don’t help “end users” much. Try to find a HyVair distributor near you, they may be more help. Distributors - Hyvair Hydraulic Pneumatic Fluid Power Components

Disclaimer, a lot of hydraulic manufacturers sells stuff to the machinery OEM with an agreement to make THEIR (often, green, red, orange or yellow) part just a little different than “standard” so the OEM has aftermarket parts all wrapped up.

Good luck

 

[rScotty]

Is the control valve leaking externally - making a mess, or is maybe leaking internally so much that it affects 4n1 operation ? I can't tell from the original post.

Your control valve may not have any O rings; most control valves do not.
Multifunction control valves are a standard industrial item. You can find them online.
So if necessary, you can replace yours with one that will work the same and may even bolt up.

Lots of threads on doing that here on TBN. If you replace it, expect that inexpensive control valves may let an implement drift from the start.
rScotty

 

[TORQUIN]

I do not have any external leaks. I believe the valve is leaking internally.
I have found my exact valve online for about 160. I was just trying to figure out if I could rebuild what I have.

Thanks,
Chris

 

[Leejohn]

Where did you find a valve for 160?

 

[TORQUIN]

D03S-2C-12D-35 HYVAIR VALVE – Wheelock Fluid Power

www.cfwheelock.com

 

[rScotty]

I do not have any external leaks. I believe the valve is leaking internally.
I have found my exact valve online for about 160. I was just trying to figure out if I could rebuild what I have.

Thanks,
Chris

Might as well give it a shot. The Hyvair website is really good with exploded diagrams, parts, explanation of part numbers and all the rest. It sure looks like if you unscrew the end caps that all the parts come out.
It would be fun to try.

https://hyvair.com/wp-content/uploads/catalogs/d03solenoid.pdf

Since it is a single spool, oil immersed, and spring centering, not much can go wrong. I'd look for a piece of crud in the valves or a broken spring. There seem to be a number of sellers online for under $200. What does Kubota want for it?

rscotty

 

[TORQUIN]

I don't know if Kubota carries it, since it was an add-on WR Long bucket they put on when I bought the tractor, new in 2004.
I spoke to someone at Hyvair and he said beyond checking the spool for trash, there isn't much I can do. I checked the spool and it's clean with no visible wear.
He said one option, besides a new valve, would be a pilot check valve I could add on if I wanted no leak-down. I am investigating that now. So far, that would be about 102, and I can add it to my current valve, since it is already leaky (something about how the pilot valve works that if I got a new main valve, I would have to use a different main valve with the pilot valve).

Chris

 

[Leejohn]

D03S-2C-12D-35 HYVAIR VALVE – Wheelock Fluid Power

www.cfwheelock.com

I was thinking a joystick valve, sorry about that.

 

[rScotty]

I don't know if Kubota carries it, since it was an add-on WR Long bucket they put on when I bought the tractor, new in 2004.
I spoke to someone at Hyvair and he said beyond checking the spool for trash, there isn't much I can do. I checked the spool and it's clean with no visible wear.
He said one option, besides a new valve, would be a pilot check valve I could add on if I wanted no leak-down. I am investigating that now. So far, that would be about 102, and I can add it to my current valve, since it is already leaky (something about how the pilot valve works that if I got a new main valve, I would have to use a different main valve with the pilot valve).
View attachment 880273
Chris

Nifty stuff. Thanks. I was hoping you would take it apart. Unfortunately, all of these sliding valves have to leak to some extent just because they have to have some clearance in order to operate. I see on the spec sheet for that valve that they have a specification for leakage. Yours might even be in spec !

I agree with the tech that the only way to absolutely stop leakage is an on/off valve. In fact, if the grapple is holding compressive force or working against gravity then you could use several of such valves- at least one in the feed and one in the return.

An alternative would be solenoid valves if you don't mind taking the extra step to engage them.

Nice to see the innards. Frankly that valve looks like a nice piece of design to me. What did you think of the assembly?
rScotty

 

[TORQUIN]

I think I will upgrade to the pilot check vale when I can afford it. It sucks when I am carrying a power pole or log, for the clamping force to slowly release and drop the pole.

Chris