bobcat 334 excavator no hydraulics????

[camshawn]

Friend has just got a 334 excavator, pulled a few blackberry bushes and the hydraulics just stopped. Fluid was a little low so he topped it up. engine shows no fault codes. Any ideas?
no blown fuses, interlock down causes light to light on control panel.
Cam

 

[lt190b]

does the blade opperate without the interlock down normally? and now it does not? if so it may be the coupling between the engine and hydraulic pump. lt190b

 

[brain55]

Yep sounds like the pump coupler. We had one that the drive would slide back on the pump shaft until it wasn't engaged anymore.

Brian

 

[camshawn]

Thanks for your responses. I was afraid that would be the problem. The blade does not move at all. Does anyone know how to get into the interlock control, there are several screws on the bottom but as it is not my machine, I am reluctant to take it apart. Is the hydraulic fluid controlled through a solenoid or is it a valve? Cam

 

[SSdoxie]

The blade is mechanical linkage control. The interlock has no control of function over the blade, if the blade does not move up or down the pump is not turning. Remove the pump and check the coupler as advised above. Remote possibility the main relief or flushing valve spool in the control is stuck wide open but pump coupler is the more common found cause.
If the blade is functioning and interlock light goes on/off with the left arm rest, problem is not in the switch on the arm rest so DO NOT take it apart. The switch sends signal to the main controller which turns the light on & off plus sends a signal to a electric solenoid which opens to send pilot oil pressure to the rest of the control valve. Either the solenoid is stuck or the, connection problem in wire from controller to the solenoid, or the accumulator has failed.

 

[camshawn]

Thanks Dennis
I have been working this Morning and Don is working as well so no action until later today.
We wil check the coupling and the pilot solenoid as first steps. As the machine is new to him, he will most likely get the selling dealer (20 min running, mostly unloading and driving to the blackberries) out if we can not get it without too much bother. I should be able to hear the interlock SV click as Don operates the interlock bar.
Cam

 

[yellowdogsvc]

I have to add that it is wonderful to have someone as knowledgeable as Doxie come in and comment.
Hope you get it figured out quickly. Good luck!

 

[camshawn]

Thanks for all your input.
Clicking when moving the interlock is pointing towards the pump coupling. defeated by darkness last night.
Cam

 

[camshawn]

Coupler gone on motor end, patched enough to move it back to whence it came.
Thanks again, Cam

 

[SSdoxie]

Thanks for letting us know.