GMC 1996 Suburban Owner's Manual page 286

Checking Brake Fluid
You can check the brake fluid without taking off the cap,
Just look at the window on the brake fluid reservoir. The
fluid level should be above MIN. If it isn't, have your
brake system checked to see if there is a leak.
After work is done on the brake hydraulic system,
make sure the level is above MIN and below the top
of the window.
What to Add
When you do need brake fluid, use only DOT-3 brake
tluid
--
such as Delco Supreme 11
@
(GM Part
No. 1052535). Use new brake fluid from a sealed
container only, and always clean the brake fluid
reservoir cap before removing it.
A
CAUTION.
With the wrong kind of fluid in your brake
system, your brakes may not work well, or they
may not even work at all. This could cause a
crash. Always use
the
proper brake fluid.
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