kubota BH90 hydraulic leak

   / kubota BH90 hydraulic leak #1  

spo307

Gold Member
Joined
Oct 2, 2007
Messages
446
Location
Levittown & Long Eddy NY
Tractor
kubota L4400
only have around 25 hours on the backhoe, and noticed hydraulic fluid dripping from under the control levers, looks like below the valves is a releif valve of some sort. anyone know what this coould be? seal? loose? thanks
 
   / kubota BH90 hydraulic leak #2  
Pics?....

Maybe Work Port Relief Valve (if it's inline with spool)....check to make sure something didn't hit valve.....

If it's 25 hrs then warranty should cover it if it's not physical damage......

Clean up and check with good strong flashlight/and or/mirror underneath.....
 
   / kubota BH90 hydraulic leak
  • Thread Starter
#3  
It wasnt hit, there is no damage, I did notice that after driving around or parking the backhoe arm will lower by itself.
 
   / kubota BH90 hydraulic leak #4  
The return gallery in the control valve is probably pressurized of some reason...check all QD's...especially the one that connect return back to tank....also check so there is no back pressure in the return line...kinks, clogged filter (unlikely) etc...
OC_valve_spool_O_rings.jpg
 
   / kubota BH90 hydraulic leak
  • Thread Starter
#5  
SORRY QD? AND IF THERE IS BACK PRESSURE HOW DO I FIX IT THANKS
 
   / kubota BH90 hydraulic leak #6  
SORRY QD? AND IF THERE IS BACK PRESSURE HOW DO I FIX IT THANKS

Quick Disconnects.....he's talking about a QD that's not completely connected....thus blocking the return flow.....
 
   / kubota BH90 hydraulic leak #7  
SORRY QD? AND IF THERE IS BACK PRESSURE HOW DO I FIX IT THANKS

Oh sorry! QD=Quick Disconnect couplers....I dont know if you have that or not....it is common that they dont connect properly if one dont pay attention....

These orings will prevent spool from leaking externally, from the return gallery....back pressure in return should not be more than 2-300psi (Max 500psi)

If orings are blown, they will need to be replaced...how depends on valve design...on some valves spool needs to come out, other can be replaced with spool still in the housing......

Get a pressure gauge T'd onto the main pump outlet line, and check pump pressure wile running on high rpm's....all valves stay in neutral...

Can you post pic's of the valve....

Also provide complete info about your backhoe/valve make, model and we'll try to find out what/how to fix...
 
   / kubota BH90 hydraulic leak #10  
As wdchyd said, there might be a work port relief valve leaking....

Back a few months ago someone here had a DCV that was hit at the WPR (bent and cracked).....IIRC it was a Kubota and the valve leaked and creeped under pressure....
 

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