190105d flashcards

Question 1

Trailer Service Lines

Answer 1

-Carries service air pressure from the tractor (from dual circuit valve or trailer hand valve) to apply trailer service brakes.
-If the trailer service line is separated, air is only lost when a brake application is made

Question 2

Trailer Supply Line

Answer 2

• The trailer supply line carry supply air from the tractor service reservoirs (through the trailer supply and tractor protection valve) to charge the trailer reservoir
  -Supply line separates, trailer emergency brakes automatically apply.
  -Air pressure falls below 50psi trailer supply valve pops out and closes leak
  -tractor protection valve closes off the service line and warning lights warn operator of low pressure.

Question 3

Relay Emergency Valve (Charging)

Answer 3

-acts as relay valve to apply, release and regulate braking pressure to the trailer service brakes.
-emergency application of brakes in even of decoupling of trailers.

Question 4

Dynamiting brakes

Answer 4

directing full trailer/tractor reservoir pressure to brake chambers.

Question 5

Releasing brakes

Answer 5

only when supply line is restored to at least 60 PSI, or air pressure is drained from the trailer reservoir.

Question 6

Pre CMVSS & CMVSS 121

Answer 6

prior to 1975(pre) anything after is cmvss121 brake systems

Question 7

Trailer spring brake valve

Answer 7

automatically applies spring brakes in supply line failure**
-prevents compounding
-

Question 8

Trailer Spring brake control valve (SR-5)

Answer 8

-acts as a relay and quick release valve for the spring brakes
-prevents compounding
-prioritizes spring brake release over filling reservoirs
-allows for faster spring brake release by using store service air
-automatically applies spring brakes when supply pressure is lost

Question 9

SR-5 check valves

Answer 9

B- maintains pressure

Question 10

sr-5 pressure protection valve

Answer 10

opens and closes to maintain 85psi supply pressure not allowing spring brakes to automatically apply

Question 11

Shut off Valve

Answer 11

operate towing vehicle as single unit, supply line must be shut off to prevent escape of supply air from glad hands

Question 12

Quick Release

Answer 12

air exhausted at back of trailer instead of flowing to supply valve.
- reduces lag time

Question 13

Pilot Relay valve

Answer 13

reinforce multiple signal pressure on multiple trailer combinations
- uses supply air to overcome cracking pressure loss to signal relay valve.
-equalizes signal pressure

Question 14

Convertor dolly

Answer 14

only trailer that doesn’t require spring brakes

Question 15

Relay emergency (Non- charging)

Answer 15

-noting happens before 45PSI.
-no check valves.
-get signal from PPV

Question 16

Pressure protection Valve

Answer 16

ensures brakes are released before reservoir is filled on just the converter dolly

Question 17

Trailer release valve (synchro valve)

Answer 17

Holds button in at 85psi