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Hey guys, thought maybe somebody could use this info. I've seen several write-ups on adding rear SCVs but not on the factory loader backhoe 1025r, which has power beyond installed. I may have missed a post about it.

So I started out by buying a rear SCV kit from Deere (BLV10838) which I now realize is specifically for a tractor with a cab. My dealer was clueless and couldn't seem to find me any information on which kit I needed exactly. So I received the kit and took it out of the box and disassembled my tractor, only to find out the power beyond already used the hydraulic ports that I was supposed to hook into for the rear SCV.

Returned the kit to John Deere. Here's what I came up with and it was about half price anyway.

Chief open center valve from tractor supply, $145

https://www.tractorsupply.com/tsc/product/chief-1-spool-hydraulic-control-3-way-or-4-way-valve

Hydraulic fittings and hoses, ~$200

I just plugged the valve into the power beyond essentially.

I thought it came together ok, 3 point hitch lever is slightly harder to access and valve can get warm when using the tractor but a simple heat shield could fix that.

I like that it's easy to swap to the backhoe because it retains the factory power beyond.

I drew up the drag scraper that's hooked on the tractor and had my buddy build it because I was busy in the fields and wanted it done in time for me to get lawn in my yard this fall yet, really happy with how that turned out also.

Thanks to everyone that posts all the good info on here, I've learned a lot.
 

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Does 3rd SCV need power beyond?

That looks like great fab work. That being said, based on my limited understanding I think there might be a problem with the way you did this. I'm not by any means a hydraulic expert or anything, but I've read most of the threads I have been able to find on here about this. It is something I'd like to possibly eventually do on my 1025R FILB I got recently. I'm sure one of the experts on here will jump in & set me straight if I'm wrong, or maybe you can enlighten me if I'm just missing something. Right or wrong it will help my understanding of how all of this works for later down the road so I'm thankful for any further input.

At first glance it looks like you added an SCV with an inlet, return, & two outputs for the new rear ports you installed. I only see four hoses connected to it in your pictures. My understanding is that for a third SCV to work correctly in this setup & not possibly risk blowing something out you have to add an SCV that has a power beyond port & a return port on it, which in my mind would mean five hoses if you have two outputs for the new rear ports. The SCV power beyond port should hook up to the power beyond return line that's there for the backhoe like you have done with what appears to be the SCV return line. My understanding is that that is necessary for the 3 point SCV that's down the line from the power beyond backhoe hose to work correctly & not risk blowing out something. The SCV return line should go directly back to the tank return. On the threads I have seen guys have done this by putting a tee in the return line from the factory SCV.

If my understanding is correct I wonder, could the valve getting hot possibly be at least partially due to more than normal pressures in the SCV or lines due to not having it plumbed with the power beyond & tank return ports?

Like I said, I'm no expert so hopefully someone will help enlighten me further about this. Regardless, great work & initiative!:bigthumb:
 

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That looks like great fab work. That being said, based on my limited understanding I think there might be a problem with the way you did this. I'm not by any means a hydraulic expert or anything, but I've read most of the threads I have been able to find on here about this. It is something I'd like to possibly eventually do on my 1025R FILB I got recently. I'm sure one of the experts on here will jump in & set me straight if I'm wrong, or maybe you can enlighten me if I'm just missing something. Right or wrong it will help my understanding of how all of this works for later down the road so I'm thankful for any further input.

At first glance it looks like you added an SCV with an inlet, return, & two outputs for the new rear ports you installed. I only see four hoses connected to it in your pictures. My understanding is that for a third SCV to work correctly in this setup & not possibly risk blowing something out you have to add an SCV that has a power beyond port & a return port on it, which in my mind would mean five hoses if you have two outputs for the new rear ports. The SCV power beyond port should hook up to the power beyond return line that's there for the backhoe like you have done with what appears to be the SCV return line. My understanding is that that is necessary for the 3 point SCV that's down the line from the power beyond backhoe hose to work correctly & not risk blowing out something. The SCV return line should go directly back to the tank return. On the threads I have seen guys have done this by putting a tee in the return line from the factory SCV.

If my understanding is correct I wonder, could the valve getting hot possibly be at least partially due to more than normal pressures in the SCV or lines due to not having it plumbed with the power beyond & tank return ports?

Like I said, I'm no expert so hopefully someone will help enlighten me further about this. Regardless, great work & initiative!:bigthumb:
Your point that you are making is a good one.

That said, without knowing the specs of the valve that the OP installed, it is hard to tell whether or not this valve is designed to see pressure on the return/tank port.
The OEM JD rear SCV valve is designed to see pressure on the return/tank port, so this is why JD can connect their OEM rear SCV in between the main SCV and rockshaft lift valve. This is not turn for many SCV's.

So, to make my point clearly..... many SCV's are not designed to see any pressure, or minimal pressure, on the return/tank port. This is why many SCV's can be set up to be used in non-power beyond applications, and also power beyond applications. When connecting into the PB circuit on these tractors, the valve is in a power beyond application as the 3 point rockshaft valve is downstream of this valve, therefore, when lifting the 3 point, this valve will see pressure on the return/tank port. If using an SCV with a PB port, then the PB port would be connected to this line so then the PB port would see the pressure which is designed to see pressure.

If the added valve is not designed to see pressure at the return/tank port, this pressure will damage the valve and potentially cause internal bypassing of oil which could get to the work ports which could cause unexpected movement of an attachment cylinder that is connected to the work ports.

So, when installing a rear SCV, and you are going to connect it to the PB only (E.g. connect the pressure port of the rear SVC to the feed port of the tractor PB, and the return port of the rear SCV to the other PB port which is the feed port for the rockshaft valve), then the valve must be designed to see pressure on the return/tank port, OR if you do connect a rear SCV that cannot see pressure on the return/tank port, then you shouldn't use the 3 point when the the rear SCV is connected.

If you intend to add a rear SCV, you essentially have two options: One, use a valve that is designed to see pressure at the return/tank port OR, Two, use a valve that can be set up with power beyond and add a tank line to the tractor.

It is possible that the valve the OP used is capable of seeing pressure in the return/tank port, I do not know. Many valves that are designed to see pressure in the return/tank port are single section valves or solenoid controlled valves.
 

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Thank you for the clarification. I was not aware that some valves have a return line that can see pressure in this fashion. I have only seen examples that required a power beyond port & an unpressurized return port on the SCV.
 

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Thank you for the clarification. I was not aware that some valves have a return line that can see pressure in this fashion. I have only seen examples that required a power beyond port & an unpressurized return port on the SCV.
Generally, multiply section SCV's cannot be pressurized at the return/tank port.
Single section SCV's sometimes are capable of seeing pressure at the return/tank port, but as always, the specs of the valve should be verified prior to buying or installing it.
As I said in my other post, the valve that JD uses OEM for the rear SCV is capable of seeing pressure at the return/tank port. This is why they can install it the way they do.

The valve that I used on my 1025R is a multiple section valve which is not capable of seeing pressure at the return/tank port so it must be set up to be used with a PB port and then the tank port must be plumbed directly to tank.
 

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Thanks for the comments, I guess I'll see how the valve holds up. I'm not too concerned about it as I only use the valve when I'm not using the 3 point, and I can easily disconnect the valve and go to the original configuration with the pioneer QCs.

The backhoe is plumbed just like this so I never gave it a thought.

I'm having a hard time understanding how back pressure on the return would negatively affect a valve. If it's an open Center valve it would automatically be manufactured to be plumbed in series, correct?

In my mind the return port on my chief valve never sees a pressure differential. In the valve neutral position, it would be flow through; while using a cylinder with the SCV it would only be waste oil flowing to the next circuit; and if using the rockshaft and it requires say 800psi to lift your implement, it would have 800psi on both sides.

Where would you find an extra return port on the 1025?

I'm not disagreeing with anybody here just trying to learn more about it! So far it has worked really well and the downstream valves work well also.
 

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Thanks for the comments, I guess I'll see how the valve holds up. I'm not too concerned about it as I only use the valve when I'm not using the 3 point, and I can easily disconnect the valve and go to the original configuration with the pioneer QCs. If you only use the valve when not using the 3 point, then there isn't a problem because you will not pressurize the return port.

The backhoe is plumbed just like this so I never gave it a thought. The reason JD can plumb the BH this way is the 3 point is removed when the BH is attached so there isn't any way you could pressurize the tank port on the BH valve.

I'm having a hard time understanding how back pressure on the return would negatively affect a valve. If it's an open Center valve it would automatically be manufactured to be plumbed in series, correct? Actually, most valves if used in series must be set up with a PB port and tank port. They cannot handle the pressure on the tank port.

In my mind the return port on my chief valve never sees a pressure differential. In the valve neutral position, it would be flow through; while using a cylinder with the SCV it would only be waste oil flowing to the next circuit; and if using the rockshaft and it requires say 800psi to lift your implement, it would have 800psi on both sides.

Where would you find an extra return port on the 1025? You have to add it.

I'm not disagreeing with anybody here just trying to learn more about it! So far it has worked really well and the downstream valves work well also.
It is possible that the Chief valve that you have can handle pressurized oil on the N port. I cannot find any info on this valve so it is hard to know. Chief seems to be pretty good at hiding their valve information. It seems like this valve can be set up as a 3 way and 4 way valve??
 

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Ya they call it a tandem center valve. I'd post a pic of the valve schematic that came in the box but it was soaked in oil when I opened it.
 

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It is possible that the Chief valve that you have can handle pressurized oil on the N port. I cannot find any info on this valve so it is hard to know. Chief seems to be pretty good at hiding their valve information. It seems like this valve can be set up as a 3 way and 4 way valve??

So I just came across this post and I am looking to do the same thing! Correct me if I am wrong. PB feed line to pump side of SCV, return line to rockshaft on PB adapter, then the two work ports on SCV to cylinder(angle for scraper blade in my case) This is OK as long as SCV and 3-point hitch(rockshaft) are not operated at the same time? Ex. 3-point up then angle left or right then 3-point down. Once 3-point is down I assume you can still angle? TIA
 

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So I just came across this post and I am looking to do the same thing! Correct me if I am wrong. PB feed line to pump side of SCV, return line to rockshaft on PB adapter, then the two work ports on SCV to cylinder(angle for scraper blade in my case) This is OK as long as SCV and 3-point hitch(rockshaft) are not operated at the same time? Ex. 3-point up then angle left or right then 3-point down. Once 3-point is down I assume you can still angle? TIA
I'm not sure what you are calling the PB feed line and the PB adapter.

Essentially the PB on a 1 series has to QC at the rear of the tractor. The OEM intended purpose of this PB is to supply hydraulic oil to a BH.

The top PB QC at the rear of the tractor feeds hydraulic oil to the BH control valve and the bottom PB QC is the feed line to the rockshaft lift.

So, when the BH is installed on the tractor, the 3 point is removed. The BH control valve feed line is connected to the top PB QC and the tank line from the BH control valve is connected to the lower PB QC. Connecting the tank line of the BH valve to the rockshaft feed line works fine for the BH control valve since there is no way to create pressure in the rockshaft lift since the 3 point is removed.

IF the rockshaft was able to be lifted with the BH attached (which it cannot be lifted since the 3 point is removed, but just for example), this would cause pressure to build in the rockshaft feed line, which would directly create pressure at the tank port of the BH control valve which is a NO NO on most control valves. Tank ports on most control valves are only designed to see a few 100 PSI of pressure, some not that much. But keep in mind, pressurizing this line with the BH installed is not possible so JD uses this the rockshaft feed line as a tank line for the BH control valve.

Now, lets talk rear SCV. IF you use a control valve like JD's OEM optional rear SCV valve, which has only one section and is capable of pressure build up at the return port, then this type of valve can simply be plugged into the PB ports, top port will feed the rear SCV and the bottom port will be the return for the rear SCV. Connected this way, your rear SCV and 3 point can be used, not simultaneously, but both can be used with no fear of damaging the rear SCV.

On the other hand, if you use a multiple section control valve that is more popular, these valves are not capable of having pressure applied to the tank port so they have to be set up with a PB port. This means the rear SCV valve will have a pressure port fed by the top PB QC at the rear of the tractor, a PB port that will be connected to the bottom PB QC at the rear of the tractor and then it will also have a tank port. The issue is, there is no OEM on a 1 series to connect the tank line to so you have to add a fitting to connect the tank line from the rear SCV to. This is where the rear SCV install becomes a non-plug and play install. Now, it isn't hard to add a tank fitting on a 1 series. I actually showed how I added one on my 1025R when I installed my rear SCV. You can see how I did mine here. Fit Rite Hydraulics Rear SCV Installation on 1025R with OEM Power Beyond

So, to answer your question, the rear SCV and 3 point cannot be operated efficiently at the same time no matter what type of rear SCV you install since the rear SCV get the oil before the rockshaft lift, the rear SCV will take precedence. The same is true concerning using the front SCV and lifting the 3 point at the same time, not possible. When using the front SCV, the 3 point will not lift.

So, the implement hydraulic oil flows to the front SCV first, out the front SCV PB port to the top rear PB QC (if you have the PB kit on your tractor), then feeds the BH control valve (if the BH is installed), and lastly to the rockshaft lift. So, if you install a rear SCV, the oil will flow from the front SCV PB port to the rear SCV feed port, then out the rear SCV PB port to the rockshaft pressure feed.

So, the front SCV gets the oil first, then the rear SCV, then the BH of rockshaft, depending on how you do the hydraulic line install on your tractor.
 

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I'm not sure what you are calling the PB feed line and the PB adapter.

Essentially the PB on a 1 series has to QC at the rear of the tractor. The OEM intended purpose of this PB is to supply hydraulic oil to a BH.

The top PB QC at the rear of the tractor feeds hydraulic oil to the BH control valve and the bottom PB QC is the feed line to the rockshaft lift.

So, when the BH is installed on the tractor, the 3 point is removed. The BH control valve feed line is connected to the top PB QC and the tank line from the BH control valve is connected to the lower PB QC. Connecting the tank line of the BH valve to the rockshaft feed line works fine for the BH control valve since there is no way to create pressure in the rockshaft lift since the 3 point is removed.

IF the rockshaft was able to be lifted with the BH attached (which it cannot be lifted since the 3 point is removed, but just for example), this would cause pressure to build in the rockshaft feed line, which would directly create pressure at the tank port of the BH control valve which is a NO NO on most control valves. Tank ports on most control valves are only designed to see a few 100 PSI of pressure, some not that much. But keep in mind, pressurizing this line with the BH installed is not possible so JD uses this the rockshaft feed line as a tank line for the BH control valve.

Now, lets talk rear SCV. IF you use a control valve like JD's OEM optional rear SCV valve, which has only one section and is capable of pressure build up at the return port, then this type of valve can simply be plugged into the PB ports, top port will feed the rear SCV and the bottom port will be the return for the rear SCV. Connected this way, your rear SCV and 3 point can be used, not simultaneously, but both can be used with no fear of damaging the rear SCV.

On the other hand, if you use a multiple section control valve that is more popular, these valves are not capable of having pressure applied to the tank port so they have to be set up with a PB port. This means the rear SCV valve will have a pressure port fed by the top PB QC at the rear of the tractor, a PB port that will be connected to the bottom PB QC at the rear of the tractor and then it will also have a tank port. The issue is, there is no OEM on a 1 series to connect the tank line to so you have to add a fitting to connect the tank line from the rear SCV to. This is where the rear SCV install becomes a non-plug and play install. Now, it isn't hard to add a tank fitting on a 1 series. I actually showed how I added one on my 1025R when I installed my rear SCV. You can see how I did mine here. Fit Rite Hydraulics Rear SCV Installation on 1025R with OEM Power Beyond

So, to answer your question, the rear SCV and 3 point cannot be operated efficiently at the same time no matter what type of rear SCV you install since the rear SCV get the oil before the rockshaft lift, the rear SCV will take precedence. The same is true concerning using the front SCV and lifting the 3 point at the same time, not possible. When using the front SCV, the 3 point will not lift.

So, the implement hydraulic oil flows to the front SCV first, out the front SCV PB port to the top rear PB QC (if you have the PB kit on your tractor), then feeds the BH control valve (if the BH is installed), and lastly to the rockshaft lift. So, if you install a rear SCV, the oil will flow from the front SCV PB port to the rear SCV feed port, then out the rear SCV PB port to the rockshaft pressure feed.

So, the front SCV gets the oil first, then the rear SCV, then the BH of rockshaft, depending on how you do the hydraulic line install on your tractor.


Thank you! This makes a lot of sense! I mention PB adapter plate because im working on 2320 and was unaware the 1 series comes equipted with PB lines installed! Basically what I understand is if I don't want to ruin anything I should run PB line from tractor to pump side of SCV, PB line from SCV to rockshaft(back to tractor), and return line(marked N) on SCV direct to tank.
 

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Thank you! This makes a lot of sense! I mention PB adapter plate because im working on 2320 and was unaware the 1 series comes equipted with PB lines installed! Basically what I understand is if I don't want to ruin anything I should run PB line from tractor to pump side of SCV, PB line from SCV to rockshaft(back to tractor), and return line(marked N) on SCV direct to tank.
That sounds correct. That said, without knowing the specs for your valve, it is not possible to say with certainty.

Most valves are marked P-for pressure in, T for tank, the PB for the power beyond but there are variations to the markings.
 

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That sounds correct. That said, without knowing the specs for your valve, it is not possible to say with certainty.

Most valves are marked P-for pressure in, T for tank, the PB for the power beyond but there are variations to the markings.
I think that I amstarting to understand this. In order to add a single valve SCV, then I sould need 5 lines, the backhoe P and R lines To the P and T ports on the SCV, 2 working ines to the cylinder that is being controlled, and a 5th line from the SCV back to the tank. So, for the single spool SCV, there would be 5 lines, correct?

Is the line that is routed back into the tank the valves power beyond line that would normally be used to feed the next downstream valve?
 
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