Frequently Asked Questions

What do you check for on the plug?

A build up of metal fragments attached to the magnet.

How often do you check the Eyemag Plug?

The Eyemag Plug should be visually checked daily during the pre-trip inspection.

On a weekly basis remove the plug to ensure that vent hole is clear and check for metal fragments.

What is the grey scum?

The grey scum is very fine metallic particle that comes from oxidization or from the machining of parts.

What volume of metal fragments would determine concern about the bearing?

Any metal particles that would build up on the magnet should be brought to the attention of service personnel for further investigation.


  1. The Eye Mag plug is simple to use. Simply remove the current plug on the wheel hug and insert the Eye Mag ensuring that it is pushed all the way in.
  2. During the pre-trip inspection the driver should take a visual look at the Eye Mag to ensure there is no debris.
  3. The Eye Mag should be removed every two to three weeks for a full visual inspection.
  4. If debris is detected this will indicate a possible bearing failure and your maintenance department should be notified.
  5. …and repeat