Mason Dynamics Blog

  • Where do I find my Monarch part number?

    You need a part for your Monarch power unit but you can’t find a part number anywhere. By following the tips below, emailing us a few pictures, and with our 50 years of Monarch experience, we should have enough info to get you taken care of.

    Pictures, Pictures, Pictures!

    Email us pictures so we’re both sure your doodad and our doohickey are the same thing.

    Complete Power Unit

    If it hasn’t been painted over or removed, there should be a sticker on the reservoir with a part # like M-319-0112 or M-3551-0137, and a serial number. Engraved in every aluminum pump base, the 1.5” thick aluminum section between the motor and reservoir, is also where you can find the serial number. A previous owner or the original distributor may have modified your power unit so it’s always a good idea to email us a few pictures so we can make sure the numbers match up with what you have.


    Check the sticker or badge on the motor for a part number. If none present, take pictures.


    Engraved on the back of the pump is a three-digit part number. Removing the reservoir will expose the pump. If you don’t see these numbers, measure the center gear section for the gear thickness. DO NOT take the pump apart.


    Part number should be engraved on the top ring or cast in the plastic housing.

    Cartridge Valve

    May have engraved part number. Removing valve from the base may be required to view. If no part number is found, refer to complete power unit tips.

    Motor Start Solenoid

    Should have a sticker or be engraved with a part number.


    Not available. Best to take measurements. The complete power unit part number is helpful if available.

    Control Box

    Not available. How many wires? Single acting or double acting circuit system?

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