Application: Tractor protection valves are commonly mounted at the rear of the cab. The purpose of the Tractor Protection valve is to protect the tractor air brake system in the event of a trailer breakaway or severe air leak. They are also used to shut off air to the trailer before disconnecting the lines.
What controls the tractor protection valve?
The TPV is also called a ‘towing vehicle’ protection valve. The TSV has a red colored, eight-sided knob and is controlled by the driver. The driver opens (pushes in) the TSV when a trailer is being towed and closes it (pulls out) when there is no trailer present.
When the tractor protection valve is opened it allows air to?
When the pressure in the supply line reaches 45 psi, the service line port of the tractor protection valve opens. This allows application air pressure to travel down the service line to the trailer when a brake application is made.
Where are the shut off valves on a tractor trailer?
These valves permit closing the air lines off when another trailer is not being towed. You must check that all shut-off valves are in the open position except the ones at the back of the last trailer, which must be closed.
Why do you need a tractor protection valve?
The purpose of the Tractor Protection valve is to protect the tractor air brake system in the event of a trailer breakaway or severe air leak. They are also used to shut off air to the trailer before disconnecting the lines.
At what PSI do air brakes lock up?
If the pressure in the air system pulls below 60 psi, the parking brake knob will pop out and set the parking brakes. This is a safety feature so the truck will stop, because if the pressure falls too low, the service brakes will not work. The other system component stops the vehicle when you push on the brake pedal.
At what pressure must the tractor protection valve operate to pass inspection?
Between approximately 20-40 PSI on a tractor-trailer combination vehicle, the tractor protection valve and parking brake valve should close (pop out). On other combination vehicle types and single vehicle types, the parking brake valve should close (pop out).
What color is the supply line on a tractor trailer?
Generally these lines are color coded where the service line is blue and the supply line is red. If the trailer connectors are not color coded, then both are usually black or silver and the emergency line will connect to the receptacle closest to the driver’s side on the front of the trailer.
What gear should the tractor engine be in after you have uncoupled?
15. You want to inspect the trailer support. You should place the tractor transmission in which gear after you have uncoupled the trailer? Neutral.
What is the emergency air line for?
Emergency air line:
The emergency line (also called the supply line) has two purposes: (1) To supply air to the trailer air tanks, and (2) to control the emergency brakes on combination vehicles. Loss of air pressure in the emergency line causes the trailer emergency brakes to come on.
What is the blue air line on a tractor trailer?
The blue line is the service brake line. This allows the trailer brakes to be applied when driving. The green line is the electrical connector.
Where are the shut off valves?
Locating the proper valve
Basements – the shut-off valve is typically located near the front foundation wall. The main water may come through the concrete floor or through the wall. The valve is typically within three to five feet of where the main water enters.
Which shutoff valve is open and closed?
All shut-off valves should be open. The valves at the back of the last trailer should remain closed. … Only the valves on the back of the first trailer should be closed.
When backing a tractor under a trailer you should?
|When backing a tractor under a trailer you should ___________.||Always use the lowest reverse gear.|
|After the trailer has been coupled to the tractor, the tractor protection control valve should be placed in what posistion?||Normal position.|