How to Replace Bushings & Bearings for Mag Drive Pumps
A bushing in the impeller of a magnetic drive pump may suffer damage over time. This damage is likely the result of three possible problems.
The first is the pump was run dry, causing the bushing to overheat and expand. We have written about the risks involved in dry running a pump.
A second scenario is if the pump was starved. This means the pump was trying to put out more liquid than what was coming in. In this case, the impeller and bushing would move forward and rub against the front housing. The front end of the bushing will wear and become damaged over time. It is also not uncommon to see wear marks on the front housing as well.
The third is the presence of solids in the liquid. Solids will wear out the bushing, possibly causing small fragments to fall off the bushing.
When a bushing does wear down, it is not always necessary to buy a new pump, a new wet end kit, or a new impeller. Often, all that is needed is to buy a new bushing and the know-how of how to install the bushing in the impeller.
The first step is to remove the damaged bushing. To remove the bushing, push it out. This is easily done with an arbor press.
The second step is to take the new bushing and press it into the impeller. Using your arbor press, set the new bushing into place. If there is difficulty pressing the bushing in, use a lubricant. If you are installing a Ryton/Teflon/Carbon or mica Teflon bushing, the bushing has to be bored out to size after installation. The carbon, ceramic, hastelloy, and silicone carbide do not require being bored out.
To determine the size, find the pump model's pump manual which will give this dimension. These pump manuals can be found on each product page of the March website. For any other questions, feel free to contact us any time!