How To Change The Polaris PB4 Pump Seal

If your pump seal is leaking on your Polaris PB4 pump you will need a few tools to remove and then install the new seal. You are going to need a basic socket set or a set of open end wrenches, a flat head screw driver, some silicon and of course your going to need a new mechanical seal. The mechanical seal in the PB4 Booster Pump is made up of two different parts and is a bit more difficult to install then the average seal in lets say the Hayward Super Pump or the Pentair Pool Pump Series. The one thing you will have to watch for is when you go to install the new seal seat. Many people break the seal seat while they are installing it. The trick is to use a large deep socket that fits over the seal spring but meets up with the outer edge of the metal seal seat.

Disconnecting the power, removing the Polaris pump from the plumbing:

Before you can repair your Polaris PB4 motor you will have to shut the power off at the filter system, unplug the pigtail cord and then either loosen the 3/4″ PVC unions or diconnect the Polaris Booster Pump Quick disconnects by pushing them down and then pulling the Polaris pump feed hoses off of the Polaris Hose barb fittings. If you have your Polaris Pump hard piped with PVC and have unions in the plumbing, you can turn the union collars counter clockwise with a pair of channel locks, then the pump will be able to be removed from the swimming pool plumbing system.

Removing the pump housing cover, the impeller:

Once you have removed the Polaris PB4 booster pump from the swimming pool plumbing you will now want to grab your socket set and remove all of the bolts that are holding the front volute / pump housing onto the seal housing. You will need to loosen the nuts and then slide the bolts out of the pump housing. Once you remove all the nuts and bolts you will be able to remove the pump housing cover, you will now see the impeller. You will now want to tap off the center cover of the rear motor end bell and you will see a slot that is in the pump shaft. You will now want to take a flat head screwdriver and stick it into that slot. You then will want to either use your hand or a strap wrench to loosen the impeller off the shaft. You will need to hold back on the motor shaft with the flat head screwdriver while you are turning the impeller counter clockwise. You will want to keep turning the impeller until it fully spins off the motor shaft.

Removing the seal housing, then replacing the new Polaris pump mechanical seal:

Now that you have removed the impeller you will have to replace both parts of the mechanical seal. One part of the seal is inside the impeller and the other part of the seal is pressed into the seal housing. You will first need to remove the seal housing from the motor by removing the four bolts that mount it to the motor housing. Once you have remove the seal housing you will want to knock the old seal assembly out of the housing and also remove the seat from the impeller. The first thing you will want to do is now apply some silicon to the seal face and install it into the impeller. Now it is time to install the second part of the Polaris mechanic seal, yes the part with the spring, this step, people often will break the seal because they don’t know how to properly press the new seal spring into the seal housing. Before you install the new seal base, you will want to apply some silicon to the outer areas of the metal. What you will want to do next is to get yourself a deep dish socket that fits over the seal spring but matches up with the outer edge of the metal base. Now you will want to center the seal assembly over the hole its fits into and then tap the socket until the seal metal base is flush with the seal housing.

Reassembling, then reinstalling the Polaris PB4 Booster Pump:

Once you have the new seal installed you can start to reassemble the Polaris PB4 Booster pump. You will want to make sure your water sling is also good before you reattach the seal housing. Once you have the booster pump all back together you can then re-install it on to your swimming pool system.