Kioti LB2204 with KL122 Loader Proportioning Valve Issue

[RandR10]

Do you have a hydraulic schematic for this tractor ? Suspect no but just curious I was thinking just replace that priority valve not the complete control block if you can determine cavity style and are confident of the circuit design.

I don't have one but I have it worked out in my head. I suspect that even if I put a brand new valve on there it might not work well since Kubota had this exact issue with this part on the B-series even when everything was doing what it was supposed to in brand new condition. I referenced the Service Bulletin in a quote in Post #6 in this thread. It won't be a huge project to put the new valve block on and I gain the ability to adjust flow in the process. One ORB plug, a jumper hose, 3 NPT to JIC fittings and a way to mount it.

 

[RandR10]

This sounds like a priority flow control valve with operate by balancing the pressure drop across the larger hole in the nose of the spool against the spring load. If the small hole in the top of the spool is plugged you would get little to no controlled flow out to steering. If the spool was binding or stuck in the sleeve or cage you would also get erratic flow to steering.

You might be able to buy that valve as a separate item if you can identify the flow rate and cavity style- size that it fits in. Standard american sizes are 7/8 - 14 thread approx 1 3/8 inches long from nose of valve to seating shoulder of retainer. Several companies build valves like this some of which are Hydra-Force, Eaton - Modular controls, Delta Power Company, Parker, etc.

other option is to clean the valve you have up and see how it operates. Do not over tighten the cage into the retainer and only torque the valve into the body to around 30 ft-lbs. Over tightening either joint can cause the valve to bind and fail.

The two tabs that broke off during disassembly might have been crimped during assembly to help keep the valve assembled.

So, I got the separate priority valve block in hand and I'm now having second thoughts about going this route because it is huge. I can still make it work if I have to, but it's already a tight fit in that area with the existing hoses, hard line and valve block. I took the valve cartridge out and took some measurements to see if I could track one down.
I found this to be a metric thread unit at M24-1.5 rather than an SAE size. Cage measures 16mm OD and 11mm ID, and the part of the cage that protrudes into the cavity is 30mm in length. Overall length of the assembled unit is 75mm. No idea what it's supposed to flow, but the pump on this machine puts out somewhere around 6-7 GPM. I even measured the spool and it is much narrower on the input side of the spool, by about 0.1mm, so its failure to function may just be from the blowby happening there. The ID of the cage measures the same top to bottom. I also found "MZ17" stamped into the top of the cap on this assembly.

You know which suppliers might make these kinds of units oldnslo? I'm going to try to track one down. If I can get one for a few hundred I figure it'll be worth it to avoid the clutter the external valve will create. Thanks again!

 

[oldnslo]

Some companies that I know of that make valves for Metric cavities are Rexroth- Oil Control
Eaton- Integrated which is now Danfoss.
Hydac
Walvoil
Parker might but not sure.
I am sure there are others.

possibly try searching for “screw in cartridge valves” to see if you get any other companies

 

[RandR10]

I've already looked at Eaton and Parker. All SAE stuff in their catalogs, what I could find anyway. I'll have to check out the others now. Thank you very much for your knowledge. Very helpful.

 

[oldnslo]

From memory I believe Rexroth- Oil Control makes valves for multiple styles of cavities like BSPP, metric, SAE, etc. and I thought Eaton Integrated did also but could be mistaken

Not super familiar with Hydac which is German based company so could also have multiple cavity styles

wishing you the best on your search

 

[K5lwq]

Michigan Iron has the one I posted the book on for $138. The part number is T2445-38621 if you would like to look it up on there parts finder. Does not mean they have it in stock but worth a call in my opinion.

 

[RandR10]

This must be a really oddball cartridge. I've looked in a whole series of catalogs and the closest dimensionally that this matches is an SAE cavity. Any of the ISO cavities I looked at are not even close and not a single one of the ones I looked at use this thread size. Parker and Eaton both have cartridges that use this thread size, but the diameters inside the cavity are much larger. I had good luck in the past with the Parker Store that was near my house in California. I think tomorrow morning I'll just walk into the local Raleigh one with it and see if they can point me in the right direction. It's kind of looking like I might be back where I started though.

 

[oldnslo]

Agree the M24 thread with 16mm OD does appear to be an oddball cavity size. Did you even consider what K5 posted about Michigan Iron option?

Can you just clean up the valve you have? Make sure you have all the rust and scale out of the inside of the spool - poppet and that the top small hole is open and free of any scale.

 

[RandR10]

Michigan Iron has the one I posted the book on for $138. The part number is T2445-38621 if you would like to look it up on there parts finder. Does not mean they have it in stock but worth a call in my opinion.

Thank you! Totally didn't see this until just now. Had the thread open in a browser window and it didn't refresh when I posted #27. Thanks to oldnslo for pointing it out. I wouldn't have looked back up the thread otherwise. Ordering the part as I write this. Looks like they have it in stock. I've never used Michigan Iron before but I'll definitely be bookmarking that site now.

By the way, I had this apart (pictured further up the thread) and cleaned it up and the spool is all scored up. It wouldn't run smoothly in the bore at all. The inlet port and the buffer port on the other end of the spool are both open and free of any crud. I tried lapping the OD into the bore of the cage with some fine grit rubbing compound, and it did smooth out the action quite a bit, but it still didn't function properly when I reinstalled it. The OD on the inlet end of the spool is about 0.1 mm smaller than the other end due to this wear, and I think it's able to cock in the bore and catch on the port holes still. I could probably get away with just a new spool, because being softer brass, it's the only thing that's noticeably damaged, but I'm glad to be able to just get the whole assembly with everything new for this price. Hopefully this fixes the problem.

 

[K5lwq]

No problem. They may not have it in stock and it may not be the same as yours but those guys are great to work with and they have never charged me until the part actually ships. Anyway, a phone call today would be a good idea.