Step 1

The piston rod oil seals retain oil in the power frame and prevent dirt, water, or other contaminants from entering the power frame by way of the piston rods. The fluid end and liners must be first removed as outlined in the previous sections to provide access to the seals.

Step 2

Rotate the oil seal nut counter clockwise until it is unscrewed from the frame, then slide off the end of the piston rod. A spanner wrench is normally used to rotate they type of nut, but a screwdriver and mallet will also work.  

Step 3

Pull the oil seal carrier out of the pump frame and slide off the piston rod. It may be necessary to insert a screwdriver or other pointed tool into one of the holes in the seal carrier to help pry out of the frame.  

Step 4

Remove the plastic washer from the power frame. The seals may now be removed from the carrier and discarded.  

Step 5

To rebuild, insert new seals in the carrier, taking care to insure they are oriented as shown. Never attempt to resuse seals that have been removed from the pump. Replace the plastic washer if it shows signs of deformation or damage.  

Step 6

Wrap tape or other material over the exposed piston rod threads to protect the new seal lips from damage. Replace the seal washer, then slide the seal carrier over the protected threads and into the pump frame. Care must be taken to insure the seal lips are not folded when passing over the ends of the piston rod.

Step 7

Once the washer and seal carrier are in place, install the oil seal nut and tighten until bottoms out. Do not overtighten as it can damage the plastic seal washer.

Step 8

Remove protective covering from piston rod threads, then rebuild fluid end as outlined in the previous sections. Torque all fasteners as outline in the Fastener Torque Requirements section of this manual.