Replace your existing grease cap with a Bearing Buddy to ensure a safe, easy way to monitor and control the level of grease in your axle hub. To adjust the amount of grease in the hub, use a grease gun to add more through the appropriate fitting. Adding grease moves the Bearing Buddy spring-loaded piston outward 1/8".
The O-ring inside the barrel of the Bearing Buddy maintains a seal from the outside. The interior of the Bearing Buddy is pressurized, preventing water from entering the barrel and diluting the grease.
An automatic pressure-relief feature is built into the Bearing Buddy. When the device is full, grease will seep around the edges of the piston and into the barrel. This prevents overfilling that can damage the inner seal.
You can manually check the grease level in your Bearing Buddy by pressing on the edge of the piston. If you can rock or move the piston, the hub is properly filled.