Oldsmobile 2004 Silhouette - Manual (Page 340)

Brakes
Brake Fluid
Your brake master cylinder reservoir is filled with DOT-3
brake fluid. See
Engine Compartment Overview on
page 5-12 for the location of the reservoir.
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 will not work well, or will
not work at all.
So, it is not a good idea to “top off” your brake fluid.
Adding brake fluid will not correct a leak. If you add fluid
when your linings are worn, then you will 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.
5-38