You are correct the shuttle portion of valve weeps through activation. I have since discounted it as it minuscule. My defense any used tractor Kioti, Kubota New Holland all have had some small weepage of oil. Now that being said no it should not leak. I read in this forum where someone addressed this loader control valve leak and what they have done to repair it. I know one owner had valve replaced altogether. Another had troubleshooted the valve but I have since forgot the details. If someone knows the repair process I would gladly try it.
