I heard that.
My 1445 does not have a charging valve.
I do have a charge pump which keeps the VSP pump full of fluid.
I believe the the newer PT hyd systems have an accumulator which is used with the brake system, and probably has a charging valve to pressurize the accumulator to a static/working pressure..
Is the valve below similar to what you are talking about.
Excerpt:
DESCRIPTION
This integrated package features a MICO Accumulator
Charge Valve and a Haldex W900 Gear Pump to accomplish
the accumulator charge function. The function of a dual
accumulator charge valve is to control the pressure in redundant
accumulators used in two or more brake circuits. When
the pressure in either accumulator decays to the specified
low limit a charge cycle is initiated. The flow rate at which the
accumulators charge is constant throughout the charging
cycle . The charging cycle is complete when the pressure
in both accumulators reaches the specified high limit. The
brake circuits are protected from pressure spikes at startup
by an internal pressure relief valve. Excess flow from the
valve may be used for steering, cooling or implement
functions. A relief valve is required for these function
http://www.mico.com/sites/default/files/documents/images/84-463-001.jpg?1346850702