L275DT - new loader power beyond question

[Crumrw]

I have an L275DT I’m currently putting a koyker 160 loader on. The tractor previously had a kubota KUFD210 snow plow blade on it. The snow plow valve had two hoses that attached to the block under the left side of the seat. The valve on the loader is currently set up as open center and has two hoses coming off of it like the plow valve did.

For the question:
I’ve read in the tractor operation manual that I need to use a power beyond capable valve for connecting to the block under the seat, and I know the loader valve is PB capable, but shows I’d need a sleeve and a third line going to tank. One, how was the original plow valve able to do it with only two lines? Everything seemed to work fine before. Two, if I have to use three lines, where does the tank line hook up and what fitting size do I need? Three, what does the power beyond sleeve do and look like? I think I might have one.

 

[Crumrw]

Is this the power beyond sleeve?

 

[TheOldHokie]

I have an L275DT I’m currently putting a koyker 160 loader on. The tractor previously had a kubota KUFD210 snow plow blade on it. The snow plow valve had two hoses that attached to the block under the left side of the seat. The valve on the loader is currently set up as open center and has two hoses coming off of it like the plow valve did.

For the question:
I’ve read in the tractor operation manual that I need to use a power beyond capable valve for connecting to the block under the seat, and I know the loader valve is PB capable, but shows I’d need a sleeve and a third line going to tank. One, how was the original plow valve able to do it with only two lines? Everything seemed to work fine before. Two, if I have to use three lines, where does the tank line hook up and what fitting size do I need? Three, what does the power beyond sleeve do and look like? I think I might have one.

View attachment 111334

In general a vanilla open center valve "works" in place of one with power beyond and many people have done just that. Potential problems you might encounter:

1) The inlet pressure relief no longer protects the pump and downstream components from over pressure conditions

2) Rubber seals in the valve are not designed to handle the back pressures created on the tank port and may fail.

3) It puts the motor or cylinders in series with down stream motors and cylinders. That can give rise to unwanted and potentially damaging interactions

Otherwise it works just fine.

The power beyond sleeve is just that. It screws into one of the tank ports and isolates the internal tank passages from the center circuit pressure eliminating the problems above.

Dan

 

[TheOldHokie]

Is this the power beyond sleeve?

View attachment 111340 View attachment 111341

No - that is a plain port thread adapter. This is a power beyond sleeve. They are specific to the individual make and model of the valve.

Dan

 

[Russell King]

For some more information on how the circuit works in general
pump generates the pressure and originally went directly to the 3 point valve that has a pressure relief valve in it.

There is probably a block installed that can be used to divert the pressure from the pump to a valve. That valve needs to then feed pressure to the next valve which will normally be the 3 point valve. The new valve should have a power beyond sleeve in it. The power beyond port is where the pump pressure is available on the new valve (when the sleeve is installed)

Since you are installing a new valve you will need to route the pump pressure into the power in port on the valve and the power beyond line to the next thing that needs pressure, probably back to the same block as the pressure feed but the opposite side of the block.

Then the tank line can be run from the new valve to a port on the top of the transmission or into the fill port on top of the transmission. The tank return is simply allowing the hydraulic cylinder to be moved by pressurized fluid on one side of the double acting cylinder that lift or lower the bucket. on the plow you may have had two single acting cylinders so they don’t need a tank return (I guess)

On my smaller but similar L185 there is a port on top of the transmission back under the seat on a cover bolted to the transmission. It looks like a large bolt head that take a large socket to remove it - maybe a 19 mm socket? That port is G 3/8 BSPP

 

[TheOldHokie]

For some more information on how the circuit works in general
pump generates the pressure and originally went directly to the 3 point valve that has a pressure relief valve in it.

There is probably a block installed that can be used to divert the pressure from the pump to a valve. That valve needs to then feed pressure to the next valve which will normally be the 3 point valve. The new valve should have a power beyond sleeve in it. The power beyond port is where the pump pressure is available on the new valve (when the sleeve is installed)

Since you are installing a new valve you will need to route the pump pressure into the power in port on the valve and the power beyond line to the next thing that needs pressure, probably back to the same block as the pressure feed but the opposite side of the block.

Then the tank line can be run from the new valve to a port on the top of the transmission or into the fill port on top of the transmission. The tank return is simply allowing the hydraulic cylinder to be moved by pressurized fluid on one side of the double acting cylinder that lift or lower the bucket. on the plow you may have had two single acting cylinders so they don’t need a tank return (I guess)

On my smaller but similar L185 there is a port on top of the transmission back under the seat on a cover bolted to the transmission. It looks like a large bolt head that take a large socket to remove it - maybe a 19 mm socket? That port is G 3/8 BSPP

Apparently his valve has a power beyond port in it but the conversion plug/sleeve is not installed. In that situation the PB port and the tank port are one and the same and it is being used to feed the 3pt.

That works in general and there are thousands of valves installed that way.

But when a downstream valve is operated the valve is seeing higher back pressure in the tank core than its designed to handle. That level of backpressure prevents the loader relief from protecting the pump and everything connected to it. It also subjects the tank core seals to pressure higher than designed. That can result in seal failure and external leaks.

Dan

 

[Fedup]

Apparently his valve has a power beyond port in it but the conversion plug/sleeve is not installed. In that situation the PB port and the tank port are one and the same and it is being used to feed the 3pt.

That works in general and there are thousands of valves installed that way.

But when a downstream valve is operated the valve is seeing higher back pressure in the tank core than its designed to handle. That level of backpressure prevents the loader relief from protecting the pump and everything connected to it. It also subjects the tank core seals to pressure higher than designed. That can result in seal failure and external leaks.

Dan

Your point is well made. I can't imagine how many times I've tried to explain this point to individuals in this same situation. Usually it sinks in, but not always. It doesn't help much when some ex spurt jumps in with his claims of having this or that system without power beyond and it's "been workin' that way for years, never had no problems." All that does is add to the confusion.

 

[Crumrw]

Ok, so I need a PB sleeve for this port on the valve (per koyker), and then route my tank to this port on the tractor for the hydraulic sump?

 

[TheOldHokie]

Ok, so I need a PB sleeve for this port on the valve (per koyker), and then route my tank to this port on the tractor for the hydraulic sump?

View attachment 111372
View attachment 111373

You have the concept right but I cannot confirm which of the ports is the PB port. Typically there is dome sort of identifyong marking on the casting. T for tank, and PB, BY, N, or possibly something else for whats high pressure carry over. (PB). You can clearly see a T next to the top port. Is there anything on the side port?

Dan

 

[Fedup]

Remove the existing fittings and/or plugs on the outlet side of the valve body and look inside the vacant ports. One will have an open space then a machined bore directly in line with the port's threads. The others will have just open space and rough cast surfaces. The machined bore is where the sleeve will seal.

 

[TheOldHokie]

Remove the existing fittings and/or plugs on the outlet side of the valve body and look inside the vacant ports. One will have an open space then a machined bore directly in line with the port's threads. The others will have just open space and rough cast surfaces. The machined bore is where the sleeve will seal.

Careful. In general that's the way it works but not always. For example the Prince Wolverine MB valves don't use a sleeve. They use an ordinary socket head pipe plug that screws into an innternal passage inside the T port. That inner passage connects the T and N cores and the plug isolates them. On those valves there is nothing installed in the N port and you cannot tell if the valve is setup for power beyond from the ourside. You have to look inside the T port to see of the plug is installed.

Dan

 

[Russell King]

The port in the tractor is the correct one for tank return- or at least it looks identical to the one on my tractor. You will need a 90 degree fitting in it to make the hose routing work. Or a straight fitting with a 90 degree hose end.

I don’t know what the block underneath your hand is in that picture or what the handle above it does but hopefully you know or the label is clear enough to understand.

I would say the block to the right of your hand with two hoses attached is the diverted block and one line is from the pump and the other is from the power beyond of the valve.

 

[Crumrw]

The port in the tractor is the correct one for tank return- or at least it looks identical to the one on my tractor. You will need a 90 degree fitting in it to make the hose routing work. Or a straight fitting with a 90 degree hose end.

I don’t know what the block underneath your hand is in that picture or what the handle above it does but hopefully you know or the label is clear enough to understand.

I would say the block to the right of your hand with two hoses attached is the diverted block and one line is from the pump and the other is from the power beyond of the valve.

Yes, that’s correct. It’s the diverter block. Per the koyker manual, the top port on the valve that I’m pointing at on the picture is the PB port. I think I’ve got it figured out now. Thanks y’all! I’ll report back with results.

 

[TheOldHokie]

Yes, that’s correct. It’s the diverter block. Per the koyker manual, the top port on the valve that I’m pointing at on the picture is the PB port. I think I’ve got it figured out now. Thanks y’all! I’ll report back with results.

Care to share the Koyker model info or a link to the manual?

Dan

 

[Crumrw]

Care to share the Koyker model info or a link to the manual?

Dan

https://d3otus7o5uizil.cloudfront.net/general-uploads/665708-160.pdf

 

[Crumrw]

 

[TheOldHokie]

https://d3otus7o5uizil.cloudfront.net/general-uploads/665708-160.pdf

Thanks. The PB sleeve seems to be cheap and readily available. Well worth your time and expense to correct the plumbing.

Dan

 

[Crumrw]

Thanks. The PB sleeve seems to be cheap and readily available. Well worth your time and expense to correct the plumbing.

Dan

Thanks, Dan. Can you point me to where you found the PB sleeve for purchase?

 

[TheOldHokie]

Thanks, Dan. Can you point me to where you found the PB sleeve for purchase?

Well here's a link to a site that seems to have sleeves for all of the Koyker loader valves. The first time I was there I was looking at the #8 sleeve which is $10. If you have the Model 160 loader you probably have a bigger valve and need a #10 sleeve which is $50. Take the plug out and measure the male threads to confirm size. They also have . short video describing the valve;

Dan

Power Beyond Sleeve (No. 10 or 5/8” O-ring port)

Koyker Part 673992. If used on a tractor with a closed center hydraulic system, adding a power beyond sleeve and a plug converts the loader control valve to a close center valve.

agpartsdirect.com

 

[Crumrw]

Well here's a link to a site that seems to have sleeves for all of the Koyker loader valves. The first time I was there I was looking at the #8 sleeve which is $10. If you have the Model 160 loader you probably have a bigger valve and need a #10 sleeve which is $50. Take the plug out and measure the male threads to confirm size. They also have . short video describing the valve;

Dan

Power Beyond Sleeve (No. 10 or 5/8” O-ring port)

Koyker Part 673992. If used on a tractor with a closed center hydraulic system, adding a power beyond sleeve and a plug converts the loader control valve to a close center valve.

agpartsdirect.com

Thanks, Dan. Purchased.

I have another question. Does anyone know the thread size and pattern of the rear axle housing plug I'm pointing at in the previous picture. My guess is that it's a 3/8-19 bspp, but am wondering if it might be ORB. Does anyone know for certain?