Charge the trailer air brake system and push the air supply knob in. Shut the engine off. Step on and off the brake pedal several times to reduce the air pressure in the tanks. The trailer air supply control should pop out when the air pressure falls into the pressure range specified by the manufacturer.

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Charge the trailer air brake system and push the air supply knob in. Shut the engine off. Step on and off the brake pedal several times to reduce the air pressure in the tanks. The trailer air supply control should pop out when the air pressure falls into the pressure range specified by the manufacturer.






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