One problem related to brake fluid leak has been reported for the 2002 Chevrolet S10. The most recently reported issues are listed below.
Brake line failure on 2002 chevy s-10 crew cab. One brake line began leaking. Dealer suggested replacing two lines. When repair was being completed a third brake line began to leak. The parts are not readily available from gm and the dealer said it could take months to get. Waiting to see if a local shop can manufacture the third line. I was told that the lines corroded due to brine used on roads during winter. I saw an article stating that the NHTSA is investigating other gm trucks between 1999 and 2003 for this very same problem but the s-10 is not listed as having an issue. I was fortunate that I caught it early by seeing a puddle of fluid under my truck. The brake light did not come on. I do not feel very confident about the remaining lines that have not been replaced.