Message text written by INTERNET:fogbro1@bellatlantic.net
>Dave,
Would you explain your answer, both parts, please. I don't understand why a
faulty valve would cause the pressure to drop when o/d is engaged
Ed Woods
<
Let me explain my theory.
Peter had a problem related to a too small ball in his actuation valve. If
this too small ball caused any deformation in the aluminum housing that
serves as the valve body then when the valve ball is raised allowing the
fluid to pass to the operating cylinders AND there is a newly developed
leak allowing pressure to leak down then the O/d will not fully engage even
though the pressure reads fine under a simple test (O/D not engaged). The
ball is raised by the 1/4 in rod which is raised by a cam on the operating
shaft. The shaft and cam are in the unpressurized reservoir and the rod
passes through a tight fitting hole in the casing. When the ball is raised
pressure is allowed to pass past the ball to the pistons. Pressure is also
present at the rod as it protrudes from the casing at that point. It the
tight fitting hole has been opened up (due to the wrong size ball being put
in there) there could be enough leakage that the pump could not keep up.
Another cause would be bad O-rings on the pistons allowing leakage. This
problem would also show it self as good oil pressure with O/D off and low
pressure with O/D engaged.
Could be a long shot, but, who knows?
Dave
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