If your cell caps are leaking, the battery is either overfilled or overcharged. There should be an air gap at the top of the cell to allow for expansion, but if too much water is added, the cell will overflow. The other cause of overflow is too high a charge voltage, causing the acid to boil over. On a 6 volt, the terminal voltage on a fully charged battery with the engine running at a fast idle shouldn't be above 7.5 volts.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!