Tip & How-To about Zoeller M53 Mighty Mate Iron Body, Poly Base Automatic Sump Pump 1/3 HP

Fixing a Zoeller M53 Sump Pump that won't turn on. Turns on by tapping or shaking.

Just wanted to share my fix story. A couple of years ago I had a problem with my zoeller sump pump to turning on but it would if I ever so lightly tapped it or the discharge pipe. Naturally I suspected the switch and replaced it with the same results. I ended up zip tying a piece of foam to the float and bingo! This worked great for awhile until the foam loosened and got stuck. So back to the drawing board. I noticed on a parts list that zoeller recommends changing the float arm when replacing the switch. Put in a new float arm and it works great! No foam needed. I never thought to replace it in the first place because the old one moved fine but when compared to the new arm the new one is much smoother. I was able to remove the old arm with channel lock pliers and the new piece is press fit with some loctite #609 that came with it. Hope this helps!

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Zoeller Pump M57

The only "easy fix" may be a stuck float switch. First make sure the outlet where the pump is plugged in works. Plug something into the outlet such as a work light to confirm the outlet is live. The float switch may be stuck in the OFF position. Giggle the float arm up and down several times to see if the pump comes on.> You can spry wd40 into the switch where the arm enters. If this does not work, the pump probably needs servicing.

Apr 07, 2014 | Zoeller Sump Pump, 3/10 HP - M57

1 Answer

my Zoeller M57 pump has stopped working. It won't even turn on...is there a reset switch or some other easy fix for this?

These Zoeller pumps are very good quality> I suspect that the float switch is not working, which is why the pump is not turning on.You may try giggling the float arm that is attached to the switch. You can also try spraying some WD 40 into the switch where the arm enters. Zoeller does have replacement parts for their pumps. Review their website for your pump parts.

50 Series Zoeller Pump Company

Apr 07, 2014 | Zoeller Sump Pump, 3/10 HP - M57

1 Answer

Fixed! Zoeller M53 won't turn on. Will turn on with a slight tap.

I had the same problem of pump not turning on unless I tapped the pipe to create a vibration. I took the float off and cleaned the grime / buildup. The buildup changed the buoyancy of the float (made it heavier) such that it did not float high enough to trigger the switch. Once cleaned, the float floats much higher above the water line and triggers the switch.

Apr 04, 2012 | Zoeller M53 Mighty Mate Iron Body, Poly...

1 Answer

My Zoeller M53 Sump Pump Shorted out since the gasket seems to have partially rotted after 2 years Itis not used that often. I opened the wrong area of the pump and drained part of the oil. WHAT TYPe Oil and how much do i put bak in the pump. Thanks

If your seal or gasket failed and water penetrated into the motor cabinet how certain are you that whatever you have done has actually remedied the underlying issue of the pump being grounded?

A new M53 is ~$125 - $150 and the oil is not something you can walk into the hardware store and pick up off the shelf. I'd want to be certain you have fixed the ground first. Having worked on these in the past it is unlikely you are going to fix anything wrong with the winding, especially for less than a new unit.

If all is OK and the oil is all you need ask around at local pump repair shops for 10 or 20 weight non-detergent pump oil...they should know what you want and if they sell it, you should be all set. As for the amount, pour it in slowly until you see the winding is fully submerged. You need to leave room at the top to allow for thermal expansion of the oil.


Aug 29, 2011 | Zoeller M53 Mighty Mate Iron Body, Poly...

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