Reversing flow on bh77

[L3902dotido]

I think I might have my hydraulic flow reversed on my new to me install L3902/BH77.

The stabilizers don't go up and down just wants to go into overpressure sound and I can't lift the boom. It seems to want to extend though.

I made a long hose from power beyond on loader and put a male end in it and plugged into bh77. Short hose female disconnect on tractor side(long hose on bh,77) to the place on hydraulic block where the original power beyond hose was ran.

Can anyone confirm this is backwards or if it will hurt string if I try to reverse flow at bh77? It has little to none hydraulic power. I can hear it going into overpressure relief when I try to activate stabilizers but they don't move. It seems to have a flow problem. It's sitting at an odd angle now, initial hookup to tractor was a fail

 

[L3902dotido]

Guns try to write current routing clearer. Loader pb port 10 foot hose with make quick disconnect plugged into female on bh 77.

Male bh77 (long lose hose) going to hydraulic block under footrest

 

[nbryan]

If loader pb port is pressure and flow "source" then the other needs to be a return path to the hydraulic sump, no?
I'm not getting it clear from your description (I own a different line/model) but can you confirm the block under footrest is return, not pressure? If both are pressure sources then those symptoms kinda make sense.
I'm prob going to get corrected by an actual L3902 owner who actually has a clue!

 

[TheOldHokie]

If loader pb port is pressure and flow "source" then the other needs to be a return path to the hydraulic sump, no?
I'm not getting it clear from your description (I own a different line/model) but can you confirm the block under footrest is return, not pressure? If both are pressure sources then those symptoms kinda make sense.
I'm prob going to get corrected by an actual L3902 owner who actually has a clue!

The block has three ports.

1. Ùpper right is pump pressure out to loader
2. Upper left is power beyond ptessure return from loader
3. Bottom center is tank return from loader.

To hook up the backhoe disconnect upper left hose on block and reroute to IN port on backhoe. This is pressure return from loader valve to hoe. Connect tank return on hoe to pressure return port on block.

The 3pt position control lever must be in the full down position when the hoe is connected. If its up you will deadhead the backhoe valve.

Dan

 

[BAP]

If you don’t have it, here is a link to the Assembly Instructions for the BH77 posted on the Kubota Books website. It shows and tells you how to hook up the hydraulics.

https://www.kubotabooks.com/AutoIndex/index.php?dir=Backhoes/&file=BH77%20Assembly%20Instruction.pdf

 

[L3902dotido]

Is the short female coupling hose on bh77 the "in" from loader? Then the loose longer make on bh77 the return? 3 point is all the way down, but the factory does have a stopper there I could remove to push it down further.

 

[L3902dotido]

I think I've got my hoses bass ackwards

 

[TheOldHokie]

I think I've got my hoses bass ackwards

Careful - in Kubota speak the tractor "outlet" hose connects to the backhoe "inlet" hose and vice versa. When looking at a diagram of just one side you need to keep that context in mind.

You know the loader power beyond hose is the tractor "outlet" hose. You need to determine which hose on the backhoe is inlet. That should be labeled on the backhoe valve.

Dan

 

[L3902dotido]

The screenshot up side labove shows the bh77 female coupler as the outlet hose. It should be going back to the block under foot rest. I've got my loader hose plugged in there in to the female end on hoe

 

[L3902dotido]

They were reversed it's fixed

 

[TheOldHokie]

They were reversed it's fixed

Simple eh???

Dan

 

[Lil Foot]

They were reversed it's fixed