Most personal equipment needs little maintenance other than careful drying out. Zips of suits are prone to clogging with mud and should be washed out before drying. Oversuits can be patched when dry if needed using glued patches. Wetsuits often require the cutting out of a damaged section and its replacement though this is fiddly, better to protect it in the first place. If leather boots are used they will require slow drying and treatment with dubbin if they are to last more than a few trips in wet caves.
Helmets require more care.
Helmets are designed to absorb impact by deformation of the cradle and by delamination of the shell in the case of fibreglass helmets. Normal caving usage subjects helmets to wear far in excess of 'normal' use and they should be replaced even if undamaged on a regular basis. Not all caves are cold and wet, but strangely all are dark. Lighting is essential. The choice is between electric sets and carbide lamps.