Chevrolet Silverado 4500HD/5500HD/6500HD Owner Manual (GMNA-
Localizing-U.S.-12102101) - 2019 - crc - 10/2/18
Vehicle Care
311
switch will close and activate the
relay, which will turn on the
backup pump.
Under normal operating conditions,
noise of the fluid flowing through the
booster may be heard whenever the
brake is applied. This is normal and
should be no reason for concern.
If braking performance or pedal
response becomes very poor, even
when the pedal is strongly applied,
this may indicate the presence of air
in the hydraulic system or fluid
leakage. Safely stop the vehicle as
soon as possible and have the
vehicle serviced right away.
Brake Fluid
The brake master cylinder reservoir
is filled with GM approved DOT 3
brake fluid as indicated on the
reservoir cap. See
for
the location of the reservoir.
Checking Brake Fluid
With the vehicle in P (Park) on a
level surface, the brake fluid level
should be between the minimum
and maximum marks on the brake
fluid reservoir.
There are only two reasons why the
brake fluid level in the reservoir may
go down:
.
Normal brake lining wear. When
new linings are installed, the
fluid level goes back up.
.
A fluid leak in the brake
hydraulic system. Have the
brake hydraulic system fixed.
With a leak, the brakes will not
work well.
Always clean the brake fluid
reservoir cap and the area around
the cap before removing it.
Do not top off the brake fluid.
Adding fluid does not correct a leak.
If fluid is added when the linings are
worn, there will be too much fluid
when new brake linings are
installed. Add or remove fluid, as
necessary, only when work is done
on the brake hydraulic system.
{
Warning
If too much brake fluid is added, it
can spill on the engine and burn,
if the engine is hot enough. You
or others could be burned, and
the vehicle could be damaged.
Add brake fluid only when work is
done on the brake hydraulic
system.
When the brake fluid falls to a low
level, the brake warning light comes
on. See
Brake fluid absorbs water over time
which degrades the effectiveness of
the brake fluid. Replace brake fluid
at the specified intervals to prevent
increased stopping distance. See