[Code of Federal Regulations]
[Title 49, Volume 5]
[Revised as of October 1, 2002]
From the U.S. Government Printing Office via GPO Access
[CITE: 49CFR570.6]

[Page 176]
 
                        TITLE 49--TRANSPORTATION
 
                            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 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.