drum brakes
drum max permitted service limit
What is .120
optimun angle for push-rod and slack adj. when applied
What is 90*
need to push in the locking collar to adj. or back-off this slack adj.
What is manual slack adj.
protects the air system from to much psi.
What is safety pop-off valve
color of air lines that come out and go to trailer
What is red and blue
drum max machining dimension
What is .090(CDX book .080)
a type 30 chamber with 50lbs. of air pressure applied
What is 1500 psi.
the link between the slack adj. and the push-rod
What is clevis and pin
pressure on this valve sends air psi. to both air systems
What is the foot valve
on the end of air lines and conects the air lines to the trailer
What are the gladhands
most common truck drum size
What is 16.5 inches
min. amount of air pressure to over-come the park brake spring
What is 60 psi.
has a wormshaft and meshing teeth, required by DOT and is most common in todays trucks
What are auto slacks
sends air to TPV to allow trailer to receive air for transport
What is trailer park valve
shuttles the spool valve back and fourth to open or close air passages to fill the trailer air tanks or apply the brakes
What is the TPV
drum is wider at outside edge then on the inside
What is bellmouthed
spring brake side of dual circuit brake chamber that can be replaced without changing the entire unit
What is piggy back
date when FMVSS 121 mandated ABS must be required on tractors
What is 3/1/97
allows park brake air to fill the spring brake chambers and allow the truck to roll free
What is tractor park valve
when you use the trailer hand valve only, what makes the brake lights come on when the switch is plumbed to the primary circuit foot valve
What is 2nd brake light switch
small cracks and signs of heat damage all over inside of drum
What is heat-checking
most common size of dual circuit brake chamber
What is 30/30 brake chamber
responds to increases in pushrod stroke to actuate a cone clutch
What is stroke sensing automatic slack adj.
receives a charge of air from TPV to allow full brake application
What is the bob-tail valve
the psi. that the trailer park brake valve will pop-out at to isolate the tractor from the trailer
What is 25-45 psi