As usual, winter — or the slow season — is the time most drillers take the time to maintain their equipment in order to get ready for the peak season. One of the main parts that usually needs attention is the mud pump. Sometimes, it is just a set of swabs to bring it up to snuff, but often, tearing it down and inspecting the parts may reveal that other things need attention. For instance, liners. I can usually run three sets of swabs before it is time to change the liner. New liners and swabs last a good long time. The second set of swabs lasts less, and by the time you put in your third set of swabs, it’s time to order new liners. Probably rods too. It’s not always necessary to change pistons when you change swabs. Sometimes just the rubber needs to be changed, saving money. How do you tell? There is a small groove around the outside of the piston. As it wears, the groove will disappear and it’s time for a new piston.
The wear groove on a piston can be a good indicator of the general health of your pump. If the wear is pretty even all around, chances are the pump is in pretty good shape. But if you see wear on one side only, that is a clue to dig deeper. Uneven wear is a sign that the rods are not stroking at the exact angle that they were designed to, which is parallel to the liner. So, it’s time to look at the gear end. Or as some folks call it, “the expensive end.”