Brake Master Cylinder - GMC 1993 Sonoma Owner's Manual

Brake Master Cylinder
Your brake master cylinder is here. It is filled with DOT-3 brake fluid.
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There are only two reasons why the brake fluid level in your master cylinder
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.
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.
you have too much brake fluid, it
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;he engir,,. The fluic
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.
Refer to the Maintenance Schedule to determine when to check your brake
fluid. See "Periodic Maintenance Inspections" in the Index.
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