Backhoe Problem with BH75 backhoe

[astavakra]

Long time lurker. I have purchased two new tractors and various equipment over the past 10 years because of recommendations from this site. This site has also helped me out with various questions and problems through searches. I couldn稚 find this one though. I know just enough about hydraulics to be dangerous, but old enough to know I don稚 know everything. So, hopefully there is an expert out there who has seen this.

Kubota L3400 308 hrs. / BH75 Backhoe has approximately 100 hrs. Purchased in 2007. UDT Super used and has been changed with filters according to manufacturers specifications. Backhoe has been kept undercover outside. Every fall after use I wash it and lube all exposed metals and grease. The hoe has not been used in 10 months. It has not been in a flood. The supply and outlet hoses are always connected together when not in use. The tractor is stored in a heated garage.

Problem. Neither one of the stabilizers/riggers will lift, the controls are frozen when trying to raise the stabilizers. It will raise or lift the hoe, but it will not lower it. When the hydraulic lines from the hoe are hooked up to the tractor the FEL will not work properly. The other controls on the hoe are free but will not work.

What I have done. I have disconnected the hoses from the stabilizers and valve body/control unit. No change. I have disconnected the linkage from the control unit and tried it directly. Still frozen.
My gut tells me there is a problem in the control unit. Am I missing something? If the control unit is damaged it must be from water. So how did water get into it? The last time I used it was last year to clean out some ditches. Some mud did get on the stabilizers, but this has happened many times before.

The retail for a control unit rebuild kit for just the stabilizers is $650 and a new unit is $2300. If it is water damage I am not inclined to fix it without knowing the cause.

Thank-you for your time. If it is the control unit/valve body I will post pics when I take it apart.

 

[powerstroke444e]

Sounds like your return line or power beyond is not hooked up all the way. Or your 3pt hitch lever is all the way up causing it to dead head? Move every hydraulic lever on the hoe and tractor listen and make sure they are all in neutral. Check quick couplers make sure they work.
It the levers don't move on how then you need to take apart the bottoms and clean and grease the springs and balls in the valve.

Welcome to tbn

 

[sandyc]

I have a 2620 with a bh65 and you have to "lock out" the three point hitch lift......is yours in the up position perchance?

 

[astavakra]

1. I hooked the tractor back up to the backhoe and checked everything. No change. The riggers still would not go back up and the left one was in the on position. FEL did not work properly at idle.

2. Removed valve body/control unit from backhoe. I first pulled the left rigger cap and was sprayed in the face with hydraulic fluid/water. I was surprised. I told you I was dangerous. The right rigger cap I wisely placed a rag over it when removing it was under pressure too. I did not remove valves, they moved freely once the caps were off. The caps were filled with a yellow cream like substance which I assume was water and fluid. The inside of the caps are corroded as well as the lower part of the spring.

3. For my own curiosity I removed the caps for the other functions. There was no fluid in any of them.

4. I reinstalled valve body/control unit on backhoe and hooked it up to the tractor. Everything now works as it should.

The water/fluid in the rigger cups apparently caused a hydro lock. The water had to have come into the system from the rigger rams, because there was no fluid in any of the other cups.
I will have to be more careful when digging to not get any mud on the riggers.

I am sad in a way that it is fixed. I was kinda looking forward to placing the backhoe in my front yard and using the bucket as a flower pot and the seat as a bird feeder. I certainly would have been the envy of some of my neighbors. Oh well.
Thanks for the help. It is comforting to know there is a place to come during these small trials.

I was going to attach pics, but it takes forever to upload.

 

[workinallthetime]

i have a bh75 on my b3030, almost 500 hours. it is not uncommon for me to run the thing in the creek with the rigger plates sumerged along with part of the ram. my bh lives on the tractor and the 2 are hardly ever seperated, im have no idea what caused your issue but in the future you might make a habbit of pairing the 2 up a little more often so they do not get seperation anxiety in the future.

 

[astavakra]

I am sure you are correct. The backhoe does miss the companionship and sharing with the tractor. I take the blame and responsibility of keeping them separated.

There is a good sized brook on the property and I was hesitant about using the tractor in it, but you have given me some ideas about maybe trying to build a waterfall.

When putting the hoe up I will now bleed both riggers and make sure I cycle them a few dozen times. Also I will change the filters more often, especially with this HST.

I think the pics should come up now.
007 L/rigger cup
008 R/rigger cup
009 Valve body

 

[Beltman60]

now you get to have the fun of re-plumbing all those lines :laughing:

 

[Wshovlin]

I bought my Kubota B7800 with backhoe BH75 and Loader LA402 about two weeks ago with 630 hours. I'm happy with it so far but I've noticed that the backhoe seems to be weeping some fluid which shows up on the surface and bottom of the backhoe control block unit. By this I mean the area below the joystick control unit. It only amounts to a few drops and seems to cover the hoe control block with slick surface of fluid and appears to stop after use. I found no apparent hose leaks and I'm wondering if it is fairly normal for the control block to just weep a small amount of fluid? Any thoughts on this?

 

[sandyc]

There should be no fluid leaking at all.

 

[rbargeron]

There are quite a few hydraulic fittings in the block of valves and it's crowded - but there's probably one that needs tightening up.