Threadlock

10g tube of Industrial Grade Threadlock.

Idea solution when rebuilding your pump .. just a drop on the thread of the magnet will ensure a properly installed magnet is held in place.

Also handy for the external nuts and bolts holding the upper and lower parts of the main casing.

Best not to use this on the threads of the valve box / diaphragms though, as you will want to avoid damaging the heads of the bolts when you come to replace or service the pump though.