Troubleshooting for vacuum motors used in Mytee equipment. 

ProblemPossible CauseSolution
Vacuum is not turning onVacuum may not be receiving power.Check for faulty connections between the motor, switch, relay and power cord. Secure any loose connections.
Vacuum is not producing suctionRecovery tank is full.Empty recovery tank.

External vacuum hose blockage (if there is no exhaust).

Check for blockage in the hose, starting from the cleaning tool to the machine.

Clogged filter in vacuum tank.
Clean out filter regularly.
Drain valve/cap is loose and is causing air leakage.
Tighten the drain cap/make sure valve is completely shut.

Hose cuffs are loose and causing air


Tighten all hose cuffs regularly as may loosen over time. Use a glue to prevent cuffs from coming loose (optional).

Lid on vacuum tank is loose and is causing air leakage.
Make sure the lid is tight.
Vacuum blows water out of the exhaust

Electronic shutoff is malfunctioning,

causing the vacuum to continue running even when the recovery tank is full.

Replace the electronic float switch with a ball float.
Foam building up in the recovery tank.
Use a defoamer 
Boot behind vacuum port is turned the wrong way.

Make sure this plastic boot is turned toward the right wall of the machine and not toward the ball float.

There is a loud grinding

noise coming from the vacuum. 

Debris has been sucked into the vacuum motor chamber. Usually results from dry vacuuming.
Replace the vacuum motor. To avoid repeat problem, DO NOT dry vacuum with your extractor.