See the attached file for sizing a pump for your application. If you are looking to replace your existing pump, the part number should be stamped into the suction side of the pump. If you can't find a part number, the gear plate thickness is the last 3 numbers of the part number. For example if the gear plate measures 1/4" (.25") then the pump would be a -250. There are four common Q pump styles, but if you need something different we also stock some other less common styles. The four common ones are:
12171-XXX For use with DC motors. Bearings bled to reservoir (pump mounted inside tank)
12172-XXX For use with AC motors. Bearings bled to reservoir (pump mounted inside tank)
12173-XXX For use with DC motors. Bearings bled to suction (can be used on units with the pump mounted externally like a M-326)
12174-XXX For use with AC motors. Bearings bled to suction (can be used on units with the pump mounted externally like a M-326)
If you are unsure of which pump you need or have any questions feel free to give us a call!
Monarch/Bucher 12173 “Q” Pump
Bearings bled to suction
Pressure o ring
Tank o ring
1 needle bearing
4 pump to base mounting screws
Note: Does not come with rear pump o ring #00116. All 12173 pumps should have this o ring in place or they will weep oil where the pump meets the base. It can be swapped from the old pump to the new pump.
Commonly used on units such as M-326 and other units with an externally mounted pump.