Most people that press the end cap straight down will find it will not move, and reach for a screwdriver. There is a better way, and it takes about two seconds once you know it.
The white cap on a Castrol grease cartridge sits flush in the mouth of the tube, held by friction against an internal rim. Pressing straight down loads the cap evenly against that rim, which is exactly what keeps it in place. The harder you press, the more firmly it seats. That is why the usual approach gets you nowhere, and why so many cartridges end up gouged open with whatever is on the bench.
The cap is designed to shear sideways, not lift out.
The technique
- Hold the cartridge in one hand with your fingers wrapped around the tube.
- Place your thumb flat across the cap, not on the edge.
- Press down and push forward at the same time. The cap only needs to travel a millimetre or two. Listen for the click.
- That click is the leading edge dropping under the rim, which lifts the opposite edge clear of it.
- Catch the raised edge and peel the cap back towards you, the way you would open a sardine tin. It stays attached at the far side and folds out of the way.
Under the cap is the grease, ready to load.
Why it is worth doing properly
A cap that has been prised off with a screwdriver leaves plastic shards and burrs at the mouth of the tube, and those can find their way into the grease and through to the bearing. A clean open also keeps the cap intact, so the cartridge can be capped again if you do not use it all in one go.
If you have a question about Castrol greases or which product suits your application, talk to the team at ILS on 0800 10 40 11 or email orders@ils.co.nz.
