Leaky Control Valve

   / Leaky Control Valve #1  

TORQUIN

Silver Member
Joined
May 22, 2004
Messages
198
Location
Powhatan, Virginia
Tractor
Kubota L3830
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
 
   / Leaky Control Valve #2  
Most hydraulic valves are metal to metal seal so there are no O-rings to replace to prevent cylinder from drifting.
 
   / Leaky Control Valve #3  
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
 
   / Leaky Control Valve #4  
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
 
   / Leaky Control Valve
  • Thread Starter
#5  
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
 
   / Leaky Control Valve #6  
Where did you find a valve for 160?
 
   / Leaky Control Valve #8  
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.

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
 
   / Leaky Control Valve
  • Thread Starter
#9  
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).
20240715_112228.jpg

Chris
 
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