AIR BRAKES- CDL Practice Questions with Multiple Choice well illustrated study guide

AIR BRAKES- d




CDL Practice Questions with Multiple Choice
d d d d d d




A device which can reduce brake lag on vehicles with air brakes is.
d d d d d d d d d d d d




a.Front wheel limiting valve
d d d


b.The quick release valve
d d d


c.The relay valve
d d


d.Tractor protection valve
d d


c. The relay valve
d d d


A slack adjuster's free play needs to be adjusted if it is more than ____ when you pull har
d d d d d d d d d d d d d d d d d d


d on it.
d d




a.1 inch
d


b.¼ inch
d


c.½ inch
d


d.2 inches
d


a. 1 inch
d d


A straight truck or bus air brake system should not leak at a rate of more than ___ psi per
d d d d d d d d d d d d d d d d d d d d


minute with the engine off and the brakes released.
d d d d d d d d




a.5
b.4
c.2
d.3
c. 2
d


A straight truck or bus air brake system should not leak at the rate of more than ______ p
d d d d d d d d d d d d d d d d d d


si within 1 minute with the engine off, parking brakes released, service brakes applied.
d d d d d d d d d d d d d




a.5
b.2
c.3
d.4
c. 3
d


A supply pressure gauge tells you how much air is in the.
d d d d d d d d d d d




a.The supply air tanks
d d d


b.Trailer brake lines
d d


c.Brake chamber
d


d.Tractor brake lines
d d


a. The air supply tanks
d d d d


Air braking takes more time than hydraulic braking because.
d d d d d d d d




a.Air takes more time to flow through the lines, which is called air delay
d d d d d d d d d d d d d

, b.Brakes require heavier return springs
d d d d


c.Air brakes use different brake drums
d d d d d


d.Air takes more time to flow through the lines, which is called brake lag
d d d d d d d d d d d d d


d. Air takes more time to flow through the lines, which is called brake lag
d d d d d d d d d d d d d d


Air tanks should be drained.
d d d d




a.All of the above are correct
d d d d d


b.Manually when automatic devices fail
d d d d


c.At the end of each day or shift
d d d d d d d


d.To keep sludge from clogging the brake system valves
d d d d d d d d


a. All the above are correct
d d d d d


All air brake equipped vehicles have.
d d d d d




a.A wigwag for low air warning
d d d d d


b.A supply pressure gauge
d d d


c.Application pressure gauge
d d


d.Hydraulic backup brake system
d d d


c. Application pressure gauge
d d d


An alcohol evaporator is used on air brake systems to...
d d d d d d d d d




a.Eliminate the need to drain air tanks
d d d d d d


b.Provide lubrication
d


c.Remove moisture
d


d.Prevent freezing
d


d. Prevent freezing
d d


Applying the service brakes when the spring brakes are on will cause.
d d d d d d d d d d d




a.Controlling pressure and could make the brakes out of adjustment
d d d d d d d d d


b.Compounding pressure and could damage the brakes
d d d d d d


c.Impounding pressure and could cause the compressor to fail
d d d d d d d d


d.Confounding pressure and could cause brake lag
d d d d d d


b. Compounding pressure and could damage the brakes
d d d d d d d


Before driving a truck or bus with a dual air brake system, the pressure in the entire syste
d d d d d d d d d d d d d d d d d


m should be at least ___ psi.
d d d d d d




a.60
b.85
c.120
d.100
d. 100
d


Brake drums or discs must.
d d d d




a.Be free of oil and grease
d d d d d


b.Both B and C are correct
d d d d d


c.Not have cracks
d d


d.Not have cracks longer than ½ the friction area
d d d d d d d d