Regional Haul Model Operator's Manual - Peterbilt Motors Company
Regional Haul Model Operator's Manual - Peterbilt Motors Company
Regional Haul Model Operator's Manual - Peterbilt Motors Company
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USING THE PARKING BRAKE<br />
(2) Trailer Air Supply<br />
Control (Red)<br />
(1) Parking Brake Control<br />
(Yellow)<br />
STARTING AND OPERATING THE VEHICLE<br />
To release the trailer brakes ONLY:<br />
• Push IN the Red knob on the dash. The truck or tractor<br />
will remain parked.<br />
Combination (Tractor/Trailer) Parking Brake Control Valves<br />
The parking brakes act on the rear wheels only. They are<br />
spring-applied, with air pressure used to release them.<br />
Release air is supplied by both the front and rear circuit<br />
reservoirs through a double check valve.<br />
To release the truck or tractor parking brakes ONLY:<br />
02394<br />
• Push IN the Yellow knob on the dash. Your trailer will<br />
remain parked.<br />
Below 60 psi (414 kPa) the Yellow parking brake valve<br />
remains OUT (ON position). If air pressure is not restored<br />
above 60 psi (414 kPa), the knob will automatically return<br />
to the OUT position if you attempt to push it in. See page<br />
42 for more information.<br />
To release the full combination of brakes:<br />
• Push IN BOTH knobs on the dash.<br />
• In the event that air pressure is reduced below a safe<br />
level: the low air warning light will come on first; if air<br />
pressure continues to drop, the parking brake valve<br />
will pop OUT, automatically applying the spring<br />
brakes.<br />
CAUTION: Do not try to put the vehicle in<br />
motion before pressure in the system<br />
reaches 100 psi (689 kPa) because the<br />
wheels are locked by the spring brake action.<br />
•Unnecessary stress and possible brake malfunction<br />
could occur if the vehicle is forced to<br />
move before the air system reaches 100 psi<br />
(689 kPa).<br />
•Below 60 psi (414 kPa) the parking brake valve<br />
button remains in the applied (ON) position. If<br />
air pressure is not restored, the button will<br />
automatically return to its initial position.<br />
– 104 – Y53-6033 <strong>Regional</strong> <strong>Haul</strong> (R05/10)