[Mark_GentryLand]

The hydraulics are hissing from the triple valves (where one plugs in the hoses). It robs power slightly, more noticeably when high rpm. The hissing stops and power restored when I press the first SCV lever slightly forward. As soon as I let go of the lever, the hissing returns. I'm thinking that a valve is not seating properly. Are there adjustments to the SCV levers?

Hissing sound is similar when operating the loader very slowly. 900 hours. Hissing sound goes away also when I mover the loader fast.

 

[Kennyd]

Welcome to DT!

I am not clear if this is the mid or rear SCV's, but I attached pics of both.

I suspect the linkages and or cables are causing the valves not to center properly and the hissing you are hearing is the PRV (pressure relief valve) activating since the fluid has no place to go.

There are adjustment on the cables, you might take the end off of the valve and make sure the levers operates smoothly. The cables can get rusty on the inside, and linkages can get dry. My go-to choice is Fluid Film to lube everything.

 

[jd110]

Another thing to check is under the detent cap(#16 first pic) is a screw in the center of the valve spool that holds the return spring to the spool. I have seen some of these screws back out and cause the valve not to neutralize properly. Jus make sure you relieve pressure on valve by working lever back and forth after engine is shut off. Then remove 2 item number 5 screws to remove detent cap and expose the center bolt. If the bolt is loose, there is your culprit.