master cylinder tank wet ?

[rustytoolss]

My 62 plymouth has an after market power disc brake conversion. It has the master cylinder with the plastic tank and 2 caps. The tank is always slightly wet. Are the tanks or cap known for fluid leakage ? or are the other reasons for the tank being damp all the time ??

 

[1STMP]

Wet on the top, I would suspect the cap seals.
Wet on the bottom, check the tank to cylinder
grommets. The tank may also have a hairline
crack. Wipe it down to dry it off, and have
someone pump the brakes and see if you
can tell where the leak is coming from.