[Code of Federal Regulations]
[Title 49, Volume 6]
[Revised as of October 1, 2006]
From the U.S. Government Printing Office via GPO Access
[CITE: 49CFR570.6]

[Page 195-196]
 
                        TITLE 49--TRANSPORTATION
 
                   CHAPTER V--NATIONAL HIGHWAY TRAFFIC
                    SAFETY ADMINISTRATION, DEPARTMENT
                            OF TRANSPORTATION
 
PART 570_VEHICLE IN USE INSPECTION STANDARDS--Table of Contents
 
          Subpart A_Vehicles With GVWR of 10,000 Pounds or Less
 
Sec.  570.6  Brake power unit.

    (a) Vacuum hoses shall not be collapsed, abraded, broken, improperly 
mounted, or audibly leaking. With residual vacuum exhausted and a 
constant 25 pound force on the brake pedal, the pedal shall fall 
slightly when the engine is started, demonstrating integrity of the 
power assist system. This test is not applicable to vehicles equipped 
with full power brake system as the service brake performance test shall 
be considered adequate test of system performance.
    (1) Inspection procedure. With engine running, examine hoses 
visually and aurally for conditions indicated. Stop engine and apply 
service brakes several times to destroy vacuum in system. Depress brake 
pedal with 25 pounds of

[[Page 196]]

force and while maintaining that force, start the engine. If brake pedal 
does not fall slightly under force when the engine starts, there is a 
malfunction in the power assist system.