gauges with cloudy oil

[pescador775]

I may be possible to refill the gauge with alcohol and water but I would choose something else. The gauge numerals or disc may have been painted. First, determine what is inside. If it is oil, after draining, clean the gauge dome with rubbing alcohol to remove oil residue. Silicone oil will not support growth of microorganisms but the solvents in the silicone may damage the gauge face over time. Mineral oil or glycerin would be safer. Of all these, glycerin is the only substance which is completely stable. It will not oxidize even in presence of pure oxygen unless a catalyst is used.