Chevrolet 2000 Cavalier Owner's Manual page 275

Brakes
Brake Fluid
There are only two reasons why the brake fluid level in the
reservoir might go down. The first is that the brake fluid goes
down to an acceptable level during normal brake lining wear.
When new linings are put in, the fluid level goes back up.
The other reason is that fluid is leaking out of the brake
system. If it is, you should have your brake system fixed,
since a leak means that sooner or later your brakes won't
work well, or won't work at all.
Your brake master
cylinder reservoir is on
the driver's side of the
engine compartment.
-
It is filled with DOT 3
brake fluid.
So, it isn't a good idea to "top off" your brake fluid.
Adding brake fluid won't correct a leak. If you add fluid
when your linings are worn, then you'll have too much
fluid when you get new brake linings. You should add
(or remove) brake fluid, as necessary, only when work is
done on the brake hydraulic system.
CAUTION:
If you have too much brake fluid, it can spill on
the engine. The fluid will burn if the engine is hot
enough. You or others could be burned, and your
vehicle could be damaged. Add brake fluid only
when work is done on the brake hydraulic system.
When your brake fluid falls to a low level, your brake
warning light will come on. See "Brake System Warning
Light" in the Index.
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