I have a l3800 and trying to add a bh77 backhoe. I removed the power beyond hose and ran lines to the backhoe. If someone has a tractor backhoe combination like this could you verify where the hoses connect on the backhoe. I now have a long hose that runs from the loader control valve and connects to the female quick connect that is mounted securely on the backhoe. The other hose runs from the block under the foot rest and terminates above the rear axle and is connected to the backhoe via a long hose from the backhoe that has a male connector. Hydraulics don’t work but it will jiggle when I hit the controls. Are the connections like the ones on your tractor or do I have them reversed or something. Oil level is at top of window. I put all new quick connections on as I suspected fluid not returning. The hoe worked a few weeks ago when I bought it off another L3800.
Bh77 backhoe hydraulic question
- Thread starter Rameyver
- Start date
Take a picture of the FEL value where you removed the hose and connected the new hose and a picture of the hydraulic block where you removed the hose and connected the other new hose. This will allow us to know if you have the hoses connected correctly.
Last edited:
From a user on TBN, he posted the BH77 install instructions BH77 install instructions CLICK HERE. You can download them from there. Starting on page 10 is the hydraulic line install for BH4988 kit which is for your L3800.
I am new to the BH77 world, but I've recently purchased one and completed the install yesterday. I am having the exact same issues as mentioned above in this thread. What was the final outcome of this issue? Sorry to be digging up threads from 2019, Thanks in advance for the help.
TheOldHokie
Well-known member
Lifetime Member
Equipment
L3901/LA525, B7200DT/B1630, G2160/RCK60, G2460/RCK60
I assume you also have a koader on that tractor? Post pictures of where your two backhoe hoses are connected to the tractor's hydraulic system.
Dan
Dan
TheOldHokie
Well-known member
Lifetime Member
Equipment
L3901/LA525, B7200DT/B1630, G2160/RCK60, G2460/RCK60
Yes when the hoses are looped everything works as it should for the front loader. When I hook it up to the BH77 and try the front loader everything works as it should as well. Fluid is going into the backhoe and back out as it should. Whenever I try any controls on the BH77 the cylinders try to move but they’re locked in position. They won’t even move when the tractor is off and there’s no pressure. I can’t figure out how to get it unstuck. It’s like all the cylinders are frozen or something’s wrong with the control valve.
TheOldHokie
Well-known member
Lifetime Member
Equipment
L3901/LA525, B7200DT/B1630, G2160/RCK60, G2460/RCK60
You seem to have the tractor side hooked up correctly so the hoe should work when connected. I am thinking you may have the hoe hooked up backwards.
Looking at the couplets on the rear which hose goes to the loader valve and where is it connected to the backhoe valve?
Dan
After troubleshooting for several days and making a trip to my local Kubota dealership yesterday I’m still stumped. The dealership guys crawled all over the tractor and triple checked the lines and hook ups and found no issues. We even compared all the lines to a brand new bh77 on the lot. I’ve attached pics in case anyone wants a look.
Service guys told me it seems to be “dead heading” and they couldn’t figure out why. They said look at the pressure relief valves and that was probably the issue. I took all of them off this morning, cleaned, inspected, and reinstalled them with no changes in my problem. My next step is to remove the entire control valve unit but I really don’t want to go down that road. I might just take it back to the dealer and wait 3+ weeks until they can take a look at it then.
Any advice is greatly appreciated. Thank you all in advance.
Attachments
TheOldHokie
Well-known member
Lifetime Member
Equipment
L3901/LA525, B7200DT/B1630, G2160/RCK60, G2460/RCK60
Relief valves operate when the pump is deadheaded to prevent damage They do not cause a pump to deadhead so my confidence in your " dealership guys" is not very great.
I have forgotten the specifics of this thread and will have to refresh my memory.
Dan
TheOldHokie
Well-known member
Lifetime Member
Equipment
L3901/LA525, B7200DT/B1630, G2160/RCK60, G2460/RCK60
This may seem redundant but humor me. You have a male and female coupler on the back of the tractor.
The male coupler is connected to a hose thst goes where?
The female coupler is connected to a pipe that goes where?
When the hose is looped to the pipe does the 3pt work correctly?
Dan
I know….I feel like it’s a simple problem but I can’t seem to figure it out.
Male coupler from tractor comes from front end loader hydraulic block and is plugged into female receiver on bh77. Female receiver on tractor comes from lower hydraulic block on right side of tractor below brakes and is plugged into male end on bh77. When everything is connected all cylinders on bh77 will not move and they act like there’s pressure there but something is stopping the flow “dead head”. The font end loader works perfectly when the bh77 is hooked up. No issues at all. When the bh77 is disconnected and looped into itself the front end loader works perfectly……
Sorry for the problem, it’s driving me nuts.
TheOldHokie
Well-known member
Lifetime Member
Equipment
L3901/LA525, B7200DT/B1630, G2160/RCK60, G2460/RCK60
OK. sounds like the tractor side is correct sndcworking asvit should.
So here is my analysis:
If the loader works when the hoe is hooked up the power beyond loop through the valve center is not deadheaded.
If operating the backhoe valve deadheads the PB supply to the BH something is wrong at the backhoe valve. My suspicion is you have the supply and return ports reversed at the backhoe valve and you are backfeeding the valve via the tank port.
Trace both of the backhoe hoses back to the valve and make sure theyvare connected to the correct ports on the valve. DO NOT GUESS.!!! Verify the connections match the instructions and post pictures of the connections with the ports labeled. iN and OUT so we can confirm.
Dan
See pic below. Spent all evening tracing hoses and double checking everything on the control valve.
The “IN” line in the picture goes to the female bh77 connector which in turn runs to the power beyond connection on the FEL block (left side hose hook up)
The “OUT” line in the picture has a male connector, goes into the female receiver on the tractor. That runs down to the hydraulic block below the brake pedals. It’s connected to the farthest left port (see pics)
Attachments
TheOldHokie
Well-known member
Lifetime Member
Equipment
L3901/LA525, B7200DT/B1630, G2160/RCK60, G2460/RCK60
You have still not verified the hose connections at the backhoe valve..
Here is a picture of the backhoe valve lifted from the BH77 WSM. Plufg your backhoe couplers in and then start at the ports on the backhoe valve and follow each hose individually all the way back to the end points on the tractor.
Verify the loader valve is connected to the P port - e.g. lower port on the backhoe valve.
Verify the hydraulic block is connected to the T port - e.g. upper port on the backhoe valve.
Last edited:
OP, have you put the 3ph control in it's mid-range? The hoe has to exhaust through the 3pt valve, and if it's dead-headed the fluid has no where to go.
TheOldHokie
Well-known member
Lifetime Member
Equipment
L3901/LA525, B7200DT/B1630, G2160/RCK60, G2460/RCK60
He says the loader is working fine so the neutral circuit is open to tank. Dollars to donuts he has T and P reversed on the backhoe valve.
Dan
Last edited:
Alright here it is……I can finally get some sleep again.
TheOldHokie was right again…. I swapped my hoses and everything stared working as it should. I still don’t understand why it’s functioning properly because it is plumbed opposite of how I read the manual but oh well. I’m moving on to actually get some work done now.
Just want to state again, took my tractor and bh77 to the dealership and had 3 mechanics craw all over it for 2 hrs and they couldn’t figure it out. Even compared it to the brand new bh77 on the lot and everything “matched up”.
I want to extend a sincere thanks to all that follow these forums and help everyone out. It’s been really helpful to get quality advice from people that know what they’re talking about.
Once again, OldHokie I hope to buy you some lunch one day for the help. You deserve much more than that for your wisdom. I’m in your debt for sure. Thanks again.