I had the common problem of an air bubble in the compass as the oil leaked out. Thanks to this forum a fellow skipper described dismantling the compass. This I did and discovered a split in the base of the expansion bellows or cup at the bottom of the oil reservoir.
Such cups are no longer available as a spare part. However I have found a wonderful British product for repairing the flexible silicone cup, called Stormsure (
www.stormsure.com). It is a glue that sets flexibly... can be used on sails, wetsuits inflatable dinghies, etc.Being ever flexible it is perfect for an expansionary bellows and is reportedly unaffected by oils and chemicals. It is not cheap but far cheaper than a new compass. A friend in the business suggests filling with 'white oil'... the pure clear stuff not the emulsion sprayed on roses!
I have also noted the used of baby oil suggested by another skipper.
