CDL
Courses
LMS
English
English
Ukrainian
Russian
Polish
Login
Home
CDL
Permit
Air Brakes #4
Practice Test
Active Practice Session
Air Brakes #4
Question 1 of 25
4% complete
Question 1
Spring brakes are usually held back by ___ during normal driving.
A
Air pressure.
B
Hydraulic fluid
C
Magnetic force
Select an answer to continue.
This website uses cookies in order to offer you the most relevant information. Please accept cookies for optimal performance.
I Agree