LA350 Hydraulic Block on mid 90s B2150HST

Windsorlocks

New member

Equipment
B2150HST w LA350
Jun 12, 2024
4
0
1
Newville, PA
Front loader hydraulic block was leaking at both valves. I pulled it apart, hand cleaned it, sonic cleaned it, polished the valves, replaced O-rings, painted the block and reassembled. Came across a small spring that appears to be for the detent (no ball found). I kept that out as I wasn't certain where it came from. It does not operate well now. Very stiff, gritty and does not float in place, needing to consistently return the lever to stay. Like many other other components, this is obsolete and very expensive. I think I'm done messing with it and looking for recommendations on a replacement unit. Have seen some on here but appear to have less line hookups and dual levers. Looking for whatever would get me closest to direct swap. Any suggestions would be appreciated. New to Kubota and tractors all together. I know it's overall not in the best shape, but it's what I can afford at the moment. Line replacement will be the next project once I find an option that doesn't cost an arm and a leg.
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Dave_eng

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M7040, Nuffield 465
Oct 6, 2012
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A friendly lesson for you.
Hydraulic valves are manufactured to tolerances you could not measure. Like instead of 0.001 think 0.0001.
You cannot do anything to make the fit better. The tolerance is so low between the spool and valve body no seals are needs as fluids cannot move through such small passages.
People who work in measurement labs are called metrologists.
Does your loader valve have 6 or 7 ports?
Others who deal regularly with Surplus Supply will easily give you a replacement item.
The springs and ball bearings external to the spool are for features like float and auto return to neutral.
If you have thought of adding more features such as a grapple now is the time as a three spool valve is not much more expensive than a 2 spool and you avoid all the complications like 3rd function valves.
From the web:

The radial clearance between the spool and bore in common, garden-variety directional control valves ranges between 3 and 13 microns.

Dave
 

North Idaho Wolfman

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L3450DT-GST, Woods FEL, B7100 HSD, FEL, 60" SB, 743 Bobcat with V2203, and more
Jun 9, 2013
30,221
6,387
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Sandpoint, ID
You will get lucky with the fact you have JIC connections, easy to connect up a new valve.
You need an open center valve with power beyond (7 hoses)



Then you will need to see if the JIC adapters will fit the new valve, if not they are cheap and easy to get.

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TheOldHokie

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L3901/LA525, B7200DT/B1630, G2160/RCK60, G2460/RCK60
Apr 6, 2021
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113
Myersville, MD
windyridgefarm.us
Front loader hydraulic block was leaking at both valves. I pulled it apart, hand cleaned it, sonic cleaned it, polished the valves, replaced O-rings, painted the block and reassembled. Came across a small spring that appears to be for the detent (no ball found). I kept that out as I wasn't certain where it came from. It does not operate well now. Very stiff, gritty and does not float in place, needing to consistently return the lever to stay. Like many other other components, this is obsolete and very expensive. I think I'm done messing with it and looking for recommendations on a replacement unit. Have seen some on here but appear to have less line hookups and dual levers. Looking for whatever would get me closest to direct swap. Any suggestions would be appreciated. New to Kubota and tractors all together. I know it's overall not in the best shape, but it's what I can afford at the moment. Line replacement will be the next project once I find an option that doesn't cost an arm and a leg.
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Here is another one of many:
I think those hoses have have also outlived their service life....

Dan
 
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Windsorlocks

New member

Equipment
B2150HST w LA350
Jun 12, 2024
4
0
1
Newville, PA
A friendly lesson for you.
Hydraulic valves are manufactured to tolerances you could not measure. Like instead of 0.001 think 0.0001.
You cannot do anything to make the fit better. The tolerance is so low between the spool and valve body no seals are needs as fluids cannot move through such small passages.
People who work in measurement labs are called metrologists.
Does your loader valve have 6 or 7 ports?
Others who deal regularly with Surplus Supply will easily give you a replacement item.
The springs and ball bearings external to the spool are for features like float and auto return to neutral.
If you have thought of adding more features such as a grapple now is the time as a three spool valve is not much more expensive than a 2 spool and you avoid all the complications like 3rd function valves.
From the web:

The radial clearance between the spool and bore in common, garden-variety directional control valves ranges between 3 and 13 microns.

Dave
A friendly lesson for you.
Hydraulic valves are manufactured to tolerances you could not measure. Like instead of 0.001 think 0.0001.
You cannot do anything to make the fit better. The tolerance is so low between the spool and valve body no seals are needs as fluids cannot move through such small passages.
People who work in measurement labs are called metrologists.
Does your loader valve have 6 or 7 ports?
Others who deal regularly with Surplus Supply will easily give you a replacement item.
The springs and ball bearings external to the spool are for features like float and auto return to neutral.
If you have thought of adding more features such as a grapple now is the time as a three spool valve is not much more expensive than a 2 spool and you avoid all the complications like 3rd function valves.
From the web:

The radial clearance between the spool and bore in common, garden-variety directional control valves ranges between 3 and 13 microns.

Dave
It appears to have 6 ports topside with 1 (assuming feed) on the side.
 

TheOldHokie

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Equipment
L3901/LA525, B7200DT/B1630, G2160/RCK60, G2460/RCK60
Apr 6, 2021
8,763
4,501
113
Myersville, MD
windyridgefarm.us
It appears to have 6 ports topside with 1 (assuming feed) on the side.
Its a standard Kubota loader valve.

You have 4 workports that connect to the cylinders

You have an inlet port that connects to the pump supply line.

You have a tank retirn port that connects to the hydraulic sump on the tractor

You have a power beyond port that supplies carry over pressure to down stream valves - specifically the 3pt.

Top or side really does not matter - you use hose ends and fittings to deal with that.

Dan
 
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Windsorlocks

New member

Equipment
B2150HST w LA350
Jun 12, 2024
4
0
1
Newville, PA
Its a standard Kubota loader valve.

You have 4 workports that connect to the cylinders

You have an inlet port that connects to the pump supply line.

You have a tank retirn port that connects to the hydraulic sump on the tractor

You have a power beyond port that supplies carry over pressure to down stream valves - specifically the 3pt.

Top or side really does not matter - you use hose ends and fittings to deal with that.

Dan
Would this be an option. Looking to be comparable but much cheaper.
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TheOldHokie

Well-known member
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Equipment
L3901/LA525, B7200DT/B1630, G2160/RCK60, G2460/RCK60
Apr 6, 2021
8,763
4,501
113
Myersville, MD
windyridgefarm.us
Would this be an option. Looking to be comparable but much cheaper.
View attachment 131205
So much cheaper its worrysome. It will do the job but you need tje power beyond sleeve which is not mentioned. Also no description of the port threads. The valve is a cheap clone of a common Europen (P40) valve so the ports are likely BSPP or SAE ORB.

I would keep looking for a seller that knows enough to provide that informstion. That style valve with the addition of float on the boom spool and a power beyond sleeve typically sells for about $275


Dan
 

TheOldHokie

Well-known member
Lifetime Member

Equipment
L3901/LA525, B7200DT/B1630, G2160/RCK60, G2460/RCK60
Apr 6, 2021
8,763
4,501
113
Myersville, MD
windyridgefarm.us
View attachment 132364
New valve arrived from surplus. How do I determine what hoses go to each port?
The four hoses in the top center of the old valve gp to the four ports on the top center of thr new valve.

The port marked T goes to tank on the tractor. You csn use either the top or side port and you must install the steel piug in the unused one.

The port marked N goes to the power beyond return port on the tractor. You must first remove the steel plug thats currently in that port and install the power beyond sleeve that hopefully you purchased with the valve. Put that plug in a bag and mark it so you dont try to reuse it. It will not fit any other port on the valve.

That leaves the P port on the left side. You connect it to the pump out port on the tractor. You can use either the top or side port and you must install the steel plug in the unused one.

I hope you ordered new hoses along with the valve....

Dan