brake help please

Depends on the condition. Always smart to get as much of the old rusty fluid out as you can before installing clean fluid. I assume you have inspected the wheels. For drums, fold back the rubber dust covers and look for leaking brake fluid. If so, replace the wheel cylinders. In that case, blow out the tubes. On my A-bodies I have done this in a general brake re-furb, so flushed all tubes w/ ethanol and air. Installed new parts and silicone brake fluid, so might never need to touch it.