Page 6-11 2005 Commercial Driver's License Manual
6.5.2 - Combination Vehicle Brake Check
Do these checks in addition to Section 5.3: Inspecting Air Brake Systems.
The following section explains how to check air brakes on combination vehicles. Check the brakes on a double or triple trailer as you would any combination vehicle.
Check That Air Flows to All Trailers. Use the tractor parking brake and/or chock the wheels to hold the vehicle. Wait for air pressure to reach normal, then push in the red "trailer air supply" knob. This will supply air to the emergency (supply) lines. Use the trailer handbrake to provide air to the service line. Go to the rear of the rig. Open the emergency line shut-off valve at the rear of the last trailer. You should hear air escaping, showing the entire system is charged. Close the emergency line valve. Open the service line valve to check that service pressure goes through all the trailers (this test assumes that the trailer handbrake or the service brake pedal is on), and then close the valve. If you do NOT hear air escaping from both lines, check that the shut-off valves on the trailer(s) and dolly(ies) are in the OPEN position. You MUST have air all the way to the back for all the brakes to work.
should be in between intakevalve movement and exhaustvalve movement Yes, valves should be closed.
Closed
Closed
Closed
Closed
Closed
Closed
Closed
One for the hot water, one for the cold.
Valve shutoff classifications refer to the ability of a valve to completely stop the flow of a fluid. The classifications include "tight shutoff," which means the valve can fully stop the flow, and "loose shutoff," which indicates some minimal leakage may occur even when the valve is closed. Different valve types and designs offer varying levels of shutoff capabilities based on their intended use and operating conditions.
There should be a fuel shutoff that needs to be adjusted, but let the car idle a couple of minutes before shutting it off and the valves should cool off enough to not diesel.
should the shut off valves on the middle trailer of a set of triples be open or closed