Four. Three externally, visible seals and one internal, non-replaceable sealed inside the main body. After replacing the three external seals, torque the solenoid, if you have oil coming out the bottom, the internal seal is leaking and solenoid replacement is necessary.
Solenoid torque is one of the most common reasons for solenoid failures, either the correct tool wasn’t used for removal or it was over-torqued. The solenoid cap, which is pressed onto the main body, determines the coil to armature clearance. The larger the clearance, the more voltage it takes to energize the solenoid. Only use the correct tool to remove and install a solenoid and do not exceed specified torque.
With all these points in mind, the question is: How much time does it take to test a solenoid versus replacing it?