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12 Cards in this Set
- Front
- Back
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What is the purpose of a two-way check valve? |
A valve which ensures a steady supply of air in the event of an air loss in onesystem. |
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Why should the glad hands be protected when not in use? |
to prevent dirt from damaging them |
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How do you control the trailer brakes independently? |
the hand valve & trailer supply valve |
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What are two ways of testing the emergency application of the trailer brakes? |
by closing the supply valve on the tractor or by disconnecting the supply line between thetractor and trailer with the supply valve in the open position. |
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Should the hand valve of a tractor trailer unit be used for parking? Why? |
no, Loss of pressure may result in loss of brakes |
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Blank |
B |
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What is the main purpose of the trailer supply valve? |
It controls the tractor protection valve & It serves as a link between the tractor and the trailer parking-brake systems by supplying air to the trailer reservoirs, through the supply line. |
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Name three functions of the relay emergency valve. |
The relay part of the valve relays air from the trailer reservoir to the trailer-brake chambers during a brake application, The emergency part of the valve directs trailer reservoir pressure to the trailer brakes causing an emergency application sometimes referred to as “dynamiting.”, The relay emergency valve has a one-way check valve that stops air in the reservoir from going back to the source of the supply. |
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Describe the function of the supply line |
its for emergency backup air |
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Describe the function of the service line |
it brings air to the brakes |
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What will occur if the supply line ruptures? |
Sudden loss of air pressure in the supply line triggers the relayemergency valve, which causes the trailer reservoir to deliver its air directly to the trailer brake chambers. This places the trailer brakes into emergency application. |
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What will occur if the service line ruptures? |
triggers the relay emergency valve |
