I believe a 3/8 Allen is the right tool.
You need a 3/8 Allen Wrench
3/8
You need a 3/8" Allen wrench to remove them.
3/8"
3/8"
It takes a FA12A Allen wrench.
Depending where it was built, a 3/8 Allen key or 15 mm regular wrench.
It should be a 3/8" Allen wrench.
3/8
Remove the two slider/anchor pins using a 3/8" Allen wrench and the caliper will come off.
the caliper bolts require a 3/8" Allen wrench. You can buy these as a socket at just about any parts store.
All Cavaliers from '94 to '03 used 3/8 Allen key on calipers.