What is the only automatic brake handle position that allows the air brake system to recharge?

What is the only automatic brake handle position that allows the air brake system to recharge?

• A. Service
• B. Emergency
• C. Full Service
• D. Release

Answer: (D)

Air brake recharge only happens when the brakes are not being applied. In the Release position, the brake valve stops sending air to the brake chambers and allows the compressor to fill the reservoirs and lines again. When you move to a service or emergency position, air is directed to the brake chambers to push the pistons and apply the brakes, which uses up the stored air and prevents charging until you return to Release. The Full Service position also applies the brakes, so it doesn’t allow recharge either. So the only position that permits the system to recharge is Release.

Air brake recharge only happens when the brakes are not being applied. In the Release position, the brake valve stops sending air to the brake chambers and allows the compressor to fill the reservoirs and lines again. When you move to a service or emergency position, air is directed to the brake chambers to push the pistons and apply the brakes, which uses up the stored air and prevents charging until you return to Release. The Full Service position also applies the brakes, so it doesn’t allow recharge either. So the only position that permits the system to recharge is Release.