reversing valve trane

replaced rev valve in a trane water source heat pump told to replace cause coil half cold an hot on top i only weighed in 1 lb r22 c alls for three was gonna use the comp to pull the rest in but my pressures are equalized in heat mode an cool mode 150 suction an head pressure do i need the full charge to make the rev valve make a full stroke

Yes, you always need the correct charge.

Perhaps the valve was over heated when installed?

no used thermal trap it was just undercharge