IHC 656 Hydraulic Control Valve problems

[Butch Z]

IHC 656 Hydraulic control valve will not return to center. We have replaced all the internal parts including springs. What are we missing?

 

[pete 23]

If all parts are assembled correctly, you may have overtightened the three bolts holding stack
together. Twenty foot pounds torque, max.

Of course the spring tension on detent is adjustable through that little plug and normally is close
to the plug being flush with end of actuator.

 

[BarnyardEngineering]

What do you mean "won't return to center?" You mean when the cylinder reaches end of travel? The screw in the end of the spool, you don't tighten that all the way down. You adjust that so the valve unlatches and returns to center.

Or, does it not spring back to center just in general? If so you put it together incorrectly.

 

[Butch Z]

We are using this Valve to operate a front end loader the valve will not come back to Center when handle is released detent is set at minimum. All parts are assembled per
parts Diagram F-56 hydraulic Control Valve Four Position Spring Centered Matching valve rebuilt at same time works fine

 

[BarnyardEngineering]

If you're not latching it into detent, detent adjustment has nothing to do with the problem.

Something wasn't reassembled correctly. Can't tell you what, because I can't see it from here.

 

[caterpillar guy]

Could that washer with the big step in it be on backwards for the spool so it doesn't get to center. Been a while since I had one apart.

 

[pete 23]

Valve is not designed to come back to center until cylinder it is operating has reached the end of it's stroke and pressures build in cylinder to the unlatching pressure set on valve.

From your description of problem it is rather difficult to know if you mean it will not come back to center when cylinder on loader is in mid stroke or has reached the end of it's stroke.