Can you provide additional details on the type of chlorides (sodium, calcium, etc.), temperature, pH, etc.? Also, what type of admiralty brass are you using (composition, product form, heat treatment)? Chlorides produce de-zincification in high Zn copper alloys, but this effect is retarded by additions of Sn. Inhibited admiralty Cu may also contain P, Ar, or Sb which further improves resistance to de-zincification. In general, this type of alloy is categorized as having "fair" resistance to CaCl2 and "poor" resistance to NaCl.