What motors it replaces: The 117478 is able to replace motor 117549 and is more powerful than the 117549 (549 airwatts compared to 483). 117478 is 0.18 inch taller than the 117549.When to replace: The signs that a 117478 Lamb motor needs to be replaced include: mini breaker popping, electrical smell, excessive blue sparks seen from motor top, you only hear a click, motor shuts down on its own but works later, or its life of 900-1,200 hours has been used up. (If you don't hear a click, then your relay most likely needs to be replaced and your motor may be fine). Five percent of the time, the minibreaker will go bad as well as the motor. If this happens, replace the motor and then evaluate the mini breaker.
How to replace: It is not difficult to replace the 117478 Ametek Motor. There are three bolts and a couple of wires. All of our customers are amazed at how easy it is. NOTE: There is no core trade-in. Used motors are thrown away. Click here to read and print out our step-by-step motor replacement instructions. Note that if the unit bolts into metal brackets then the ground wire can be snipped. If plastic then attach the ground wire to the ground from the power cord or anywhere to metal on the unit.Replacing motor brushes: The Lamb 117478 vacuum motor has carbon motor brushes that can be replaced. This should be done before a motor is "on its last legs." Read more about changing the motor brush on the detailed motor brush how-to page. If you are ready to replace your motor brushes, here is a link to the Ametek 117478 Motor Brush. You will need to buy two.