"Power Beyond" hydraulic question

[flyboyx]

ok, so....i have this kubota L275 with a factory bf400 loader. i recently added power steering and remote outlets to run the jd48 backhoe pictured.



i have a problem running the backhoe when the loader is connected. i have them hydraulically connected in parallel. since the loader is power beyond, i suppose this control block dumps the hydraulic pump pressure back to the sump instead of sending pressure to the hoe. i can disconnect the pressure port to the loader and the backhoe works fine. i suppose i could put a ball shut off valve in the pressure line on the loader to solve my dilemma, but i am hoping someone knows more about power beyond systems than i do and can suggest a way to hook the loader/backhoe/power steering up so it can all be used together.

here is a photo of my connections. you can see the integral power steering block in the system.



one idea that i thought of would be to cap off the pressure line going to the rear outlets, connect that to the downstream side of the loader so my backhoe will be in series. if anyone has an idea how to make it work better, please let me know.

 

[Ductape]

Your tractor's hydraulics need to be plumbed in series only. Generally the circuit will go through the loader, then backhoe, then to the 3 point. The only lines that can be Tee'd are the return lines going back to the sump. When plumbed in parallel the hydraulic pressure will always take the path of least resistance...... which is why you are having a problem now.

 

[kennyd]

Your tractor's hydraulics need to be plumbed in series only. Generally the circuit will go through the loader, then backhoe, then to the 3 point. The only lines that can be Tee'd are the return lines going back to the sump. When plumbed in parallel the hydraulic pressure will always take the path of least resistance...... which is why you are having a problem now.

Welcome to TBN Flyboyx

What Ductape wrote is 100% correct. You need to use the PB port from the loader valve to feed the IN port on the remote valve, then the PB port on the remote valve to feed the 3PH. The OUT ports are low pressure and carry "waste oil" from the work ports-they are the only ones that can be Tee'd.

 

[flyboyx]

hey, thank you guys for the reply. thats what i was afraid of. so...the bf400 has one pressure line and two returns for some reason. one dumps into the hydraulic block beside the seat and the other drops into the top of the mid transmission case. does it matter which one of those returns i use as the pressure line for my hoe?

i was thinking to cap off the pressure line that i have teed(top of photo), disconnect the lower return and run that as the pressure line back to the hoe. that would be in series but would it work that way?

 

[kennyd]

hey, thank you guys for the reply. thats what i was afraid of. so...the bf400 has one pressure line and two returns for some reason. one dumps into the hydraulic block beside the seat and the other drops into the top of the mid transmission case. does it matter which one of those returns i use as the pressure line for my hoe?

i was thinking to cap off the pressure line that i have teed(top of photo), disconnect the lower return and run that as the pressure line back to the hoe. that would be in series but would it work that way?

Two returns? Is one marked PB or BYD on the valve?

 

[Ductape]

flyboyx, logic would dictate that the line going back to the hydraulic block is power beyond (pressure), and powers your 3 point hitch....... and the line returning to the middle of the trans case is an unpressurized return to the sump. BUT..... as Kenny indicated, it would be best to see if the ports on the valve are marked or attempt to get a schematic to be sure.

 

[flyboyx]

yes, i agree that the return line that runs to the hydraulic block under the seat is there to operate the three point hitch. i haven't noticed any labels on the ports but i will check it out when i get back home from my trip this weekend. probably the safest course of action would be to use the return to the three point to power my remotes. i wish someone had some suggestions on how i could accomplish this without that area of my tractor looking like it was hillbilly engineered. i didn't really want to cut my factory loader lines or screw them up in any way.

if i can come up with a way to connect that upper return directly to my remote outlet, i can have the return remote feed directly into the return port under the seat. no tee fittings would be required. another advantage is that when i don't have my hoe hooked up, i will be able to plug the remote outlets back into each other to complete the circuit and they will stay clean

 

[Ductape]

Yeah, as I said earlier, the norm is to go from the pump through the loader. PB out of the loader to the backhoe remotes, then the PB (or out) from the backhoe back to the hydraulic block and to the three point. The return line coming out of the loader (and the third, unpressurized line out of the backhoe if it has one) just returns to the sump (these are the only lines that can be Tee'd). This how my tractor is plumbed also. The remotes for the backhoe MUST be plugged into each other when the hoe is not connected....... not just to keep them clean, but to keep your hydraulic pump from dead heading. Alot of tractors, especially older tractors, aren't protected by a pressure relief valve. My old Yanmar was like this. Running the tractor without the circuit complete for a couple seconds can either shear the key on the hydraulic pump (if you're lucky) or destroy the hydraulic pump. Until you're sure there is a pressure relief, NEVER start your tractor with your rear remotes disconnected.

 

[rbargeron]

Not sure about yours but many loader control valves can be configured with or without power-beyond. On a 2-spool Cross valve I have the fitting in the PB port can be removed and replaced with a plug to eliminate the PB function. With that change, and with remotes plugged together when not in use, your control valves could be plumbed in series and then it should work. As always, prompt cheerful refund if info is bogus.

 

[kennyd]

yes, i agree that the return line that runs to the hydraulic block under the seat is there to operate the three point hitch. i haven't noticed any labels on the ports but i will check it out when i get back home from my trip this weekend. probably the safest course of action would be to use the return to the three point to power my remotes. i wish someone had some suggestions on how i could accomplish this without that area of my tractor looking like it was hillbilly engineered. i didn't really want to cut my factory loader lines or screw them up in any way.

if i can come up with a way to connect that upper return directly to my remote outlet, i can have the return remote feed directly into the return port under the seat. no tee fittings would be required. another advantage is that when i don't have my hoe hooked up, i will be able to plug the remote outlets back into each other to complete the circuit and they will stay clean

Yeah, as I said earlier, the norm is to go from the pump through the loader. PB out of the loader to the backhoe remotes, then the PB (or out) from the backhoe back to the hydraulic block and to the three point. The return line coming out of the loader (and the third, unpressurized line out of the backhoe if it has one) just returns to the sump (these are the only lines that can be Tee'd). This how my tractor is plumbed also. The remotes for the backhoe MUST be plugged into each other when the hoe is not connected....... not just to keep them clean, but to keep your hydraulic pump from dead heading. Alot of tractors, especially older tractors, aren't protected by a pressure relief valve. My old Yanmar was like this. Running the tractor without the circuit complete for a couple seconds can either shear the key on the hydraulic pump (if you're lucky) or destroy the hydraulic pump. Until you're sure there is a pressure relief, NEVER start your tractor with your rear remotes disconnected.

I to believe the "upper" hose is just a tank line-so it will do nothing for you. You need the line that feeds the 3PH to feed the backhoe valve and remotes.

And if I may be blunt...as far as "looks" and "hillbilly engineering" go? You already have a JD hoe on a Kubota tractor

 

[flyboyx]

And if I may be blunt...as far as "looks" and "hillbilly engineering) go? You already have a JD hoe on a Kubota tractor

HAHAHAHA!!!!:laughing::laughing: that's funny schiz! yes its green, but it was a really good deal that i couldn't pass up.

i have come up with a pluming plan. i will post a photo after i get it together and try it out. now that i know for sure(from all of your advice) that it needs to be in series i can work with it. i just spent 20 minutes on discounthydraulics.com sourcing fittings. unfortunately, they have a 20.00 minimum and as hard as i try, i can't come up with more than 16.00 worth of parts(dang-it!)

 

[kennyd]

HAHAHAHA!!!!:laughing::laughing: that's funny schiz! yes its green, but it was a really good deal that i couldn't pass up.

i have come up with a pluming plan. i will post a photo after i get it together and try it out. now that i know for sure(from all of your advice) that it needs to be in series i can work with it. i just spent 20 minutes on discounthydraulics.com sourcing fittings. unfortunately, they have a 20.00 minimum and as hard as i try, i can't come up with more than 16.00 worth of parts(dang-it!)

Thanks for taking that well:thumbsup:

As for DHH, get some Bulkhead Fittings or some Protective Sleeving?

 

[flyboyx]

The remotes for the backhoe MUST be plugged into each other when the hoe is not connected....... not just to keep them clean, but to keep your hydraulic pump from dead heading. Alot of tractors, especially older tractors, aren't protected by a pressure relief valve. My old Yanmar was like this. Running the tractor without the circuit complete for a couple seconds can either shear the key on the hydraulic pump (if you're lucky) or destroy the hydraulic pump. Until you're sure there is a pressure relief, NEVER start your tractor with your rear remotes disconnected.

thank you ductape. fortunately, my tractor has pressure relief. it isn't very visible in the photo i posted above, but it is the last component on the far right side behind the lines. before i had the loader, i had to plug the remotes together in order for the three point to work.

 

[Ductape]

Just wanted to let you know what the worst case scenario might be. Let us know how it turns out once you get your plumbing rearranged. You've obviously got a good handle on it. :thumbsup:

 

[flyboyx]

on my way back home from new york this evening i sketched out a diagram and took a couple of photos from my tractor and loader manuals. as posted above, this photo is my setup now:



here is the diagram i drew on my flight tonite:



this diagram is to be viewed with the two male elbows toward the bottom right going into the hydraulic block on the tractor. the flare fittings on the left connect to the factory loader lines.

here is a pic from my bf400 loader manual:



this one is from the section in my l275 owners manual that deals with hydraulics.



in the hand drawn diagram above, i have the pluming set up to run through the loader first, remotes/back hoe second, and three point last. i did this at ductape's suggestion in the first reply above. my question is....: is it really necessary to run through the loader first? my backhoe is also power beyond and since everything is in series, does it really matter? my reasoning for asking is i am a little concerned about that third line from the loader that dumps off onto the mid case. the loader diagram lists that as the "return line". however, i know that if i were to tie into that(i have no intention of doing so) i won't have a complete circuit to my three point. i am a little worried if the loader gets first crack at the hydraulic fluid, that third line may somehow effect the flow rate to the hoe. any thoughts?

 

[kennyd]

It does not really matter which valve gets the fluid first, but it is common for the FEL valve to be first in the "loop". In a PB type setup, all valves have equal access to the available flow from the pump. Say you have 10 gpm total flow, that is available at the first or last valve-unless a upstream valve is using some of it. Since you won't be using the loader and hoe at the same time, it does not matter.

 

[flyboyx]

well, i re-plumbed my hydraulic system. i went from parallel to series as you folks suggested. everything works great. now i am thinking about adding another control valve to run a spare cylinder for a few various tasks. anyway, here is a pic.

 

[kennyd]

well, i re-plumbed my hydraulic system. i went from parallel to series as you folks suggested. everything works great. now i am thinking about adding another control valve to run a spare cylinder for a few various tasks. anyway, here is a pic.

Good news.. looks great!:thumbsup:

 

[Ductape]

I agree...... you did a nice job on the plumbing. Now that you have the hydraulics mastered, might as well add a couple spools to it....... then you can have a hydraulic top link AND tilt !

 

[flyboyx]

I agree...... you did a nice job on the plumbing. Now that you have the hydraulics mastered, might as well add a couple spools to it....... then you can have a hydraulic top link AND tilt !

i agree, i would like to. i want to add a grapple to my loader and i would like to have a spool to run a jack hammer on the end of my hoe. do any of you guys have an idea where i can find a power beyond control valve at a reasonable price? i have a random dual control valve that i purchased at an auction a couple of years ago. how do i know if it is power beyond? i can snap a pic of it and the data plate if that helps.

brian