GMC 2010 T-Series, Owner'S Manual

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Parking Brake Burnish Procedure
All vehicles which have hydraulic brakes will have a
parking brake. It is recommended that the parking brake
be burnished as part of the new vehicle break-in. The
parking brake will work best after it has been burnished
following these instructions:
1. Making sure that there is no other traffic around,
get the vehicle speed up to 20 mph (32 km/h) and
pull up to apply the parking brake. Let the vehicle
come to a complete stop. Apply the base brakes
and disengage the parking brake.
2. Repeat the burnishing procedure in Step 1 a total
of 10 times.
3. Between stops, drive the vehicle about
2 ½ miles (4 km).
Notice: Driving with the parking brake on can
damage the transmission and brake system parts.
Verify that the parking brake is fully released and
the brake warning light is off before driving.
Air Suspension
The vehicle may have the Hendrickson HAS Series
single-axle air suspension which is designed for a
single-axle on-highway use. This feature is available in
19,000 lb (8 613.3 kg), 21,000 lb (9 525.4 kg) and
23,000 lb (10 432.6 kg) capacities.
Rear Air Suspension Dump Control
If the vehicle is equipped with the Hendrickson HAS
Series single-axle air suspension, you may have this
control. The air suspension dump control allows the
operator to lower the deck height approximately
4.5 inches (11.5 cm) from the normal frame height.
The switch to deflate and
inflate the air suspension
is located on the
instrument panel.
Press the bottom of the switch to deflate the air
suspension and lower the deck height. Press the top
of the switch to return the suspension to normal deck
height.
An indicator light will come on and stay on whenever
the switch is in the dump position.
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