Single Car Test includes eight tests: Leakage Test, Sensitivity/Insensitivity Test, Brake Application/Release Test, Graduated Application/Release Test, Emergency Application Test, Passenger Emergency Valve Test, Guard's Emergency Valve Test, and Slack Adjuster Check.

Coaches brought for Schedule 'C' maintenance are subjected to Single Car Test along with other maintenance activities.

Full service brake application requires a brake pipe pressure reduction of 1.0 to 1.5 kg/cm².

Minimum brake application requires a brake pipe pressure reduction of 0.5 to 0.8 kg/cm².

When brake pipe pressure rises to 4.85 kg/cm² during release, the brake cylinder is completely drained and brakes are fully released.

The double release valve provides for accelerated manual brake release, particularly useful during shunting operations.

Insensitivity test checks that brakes do not apply when BP pressure drops at a very slow rate of 0.3 kg/cm² in 60 seconds.

During hydraulic testing, the auxiliary reservoir must withstand 16 kg/cm² pressure for 5 minutes without leakage or bulging.

The cut-off angle cock uses a stainless steel ball that rotates on nitrile rubber seats.

The intermediate piece blanks all ports on the common pipe bracket except those required for a particular make of distributor valve.

During brake release, the brake cylinder pressure should fall from maximum to 0.4 kg/cm² within 15 to 20 seconds.

During full service application, the brake cylinder pressure should rise from 0 to 3.6 kg/cm² within 3 to 5 seconds.

During leakage test, the drop in brake pipe pressure should not exceed 0.2 kg/cm² in one minute.

The distributor valve is overhauled once in five years or on completion of 8 lakh km, whichever is earlier, or if there is specific trouble.

The drop in brake pipe pressure is observed on the airflow meter in the locomotive cabin.

Pulling the chain vents air from the control pipe, causing BP to exhaust through the PEAV's 4 mm choke, resulting in partial brake application.

PEASD is the manually operated pilot vent valve connected to the alarm chain inside coaches.

A 5 mm choke controls the rate of brake pipe exhaust when the guard operates the emergency valve.

A 3 mm choke is fitted at the outlet port of the check valve to ensure uniform filling of auxiliary reservoirs in all coaches.

Check valve allows air flow in one direction (towards auxiliary reservoir) and prevents reverse flow, maintaining AR pressure.

The auxiliary reservoir is continuously charged from the feed pipe at 6 kg/cm² pressure.

The 'e' dimension (distance between protection tube end and mark on adjuster spindle) represents the available adjustment capacity and should be 375 ± 25 mm.

For 16.25 tonne bogie coaches, the 'A' dimension should be 22 +2/-0 mm.

For 13 tonne bogie coaches, the 'A' dimension (distance between control rod head and barrel head) should be 16 +2/-0 mm.

All BP angle cocks are kept open except the rear end cocks to maintain system pressure throughout the train.

In closed position, the ball rotates and closes the inlet while the outlet air is vented through the vent hole.

When the handle is parallel to the cock body, the inlet and outlet ports are connected through the ball, allowing air to pass.

Cut-off angle cocks are provided at both ends of each coach to facilitate coupling and uncoupling of air hoses.

Dirt collector is placed in the brake pipe and feed pipe lines to remove dust particles through centrifugal action and filtration.

During single car test, the brake cylinder piston stroke should be between 85 to 130 mm when brakes are applied.

The distributor valve limits the maximum brake cylinder pressure to 3.8 ± 0.1 kg/cm² for full service or emergency application.

Slack adjuster automatically maintains correct clearance between brake blocks and wheels through its 'A' dimension.

Every coach fitted with air brake system has two brake cylinders for actuating the brake rigging.

The distributor valve is the most important functional component as it senses pressure changes and controls brake application and release.

Feed pipe coupling heads are painted white and have "FP" embossed on them.

Brake pipe coupling heads are painted green and have "BP" embossed on them for easy identification.

Brake application takes place when the pressure in the brake pipe is reduced by venting air through the driver's brake valve.

The feed pipe is charged to 6 kg/cm² pressure throughout the train length and continuously charges the auxiliary reservoir.

During normal running condition, the brake pipe is charged to 5 kg/cm² pressure throughout the length of the train.

The air brake system uses compressed air generated by the locomotive compressor to operate the brakes throughout the train.