[Code of Federal Regulations]
[Title 49, Volume 5]
[Revised as of October 1, 2007]
From the U.S. Government Printing Office via GPO Access
[CITE: 49CFR393.78]

[Page 429-430]
 
                        TITLE 49--TRANSPORTATION
 
                      DEPARTMENT OF TRANSPORTATION
 
PART 393_PARTS AND ACCESSORIES NECESSARY FOR SAFE OPERATION--Table of 
Contents
 
              Subpart G_Miscellaneous Parts and Accessories
 
Sec.  393.78  Windshield wiping and washing systems.

    (a) Vehicles manufactured on or after December 25, 1968. Each bus, 
truck, and truck-tractor manufactured on or after December 25, 1968, 
must have a windshield wiping system that meets the requirements of 
FMVSS No. 104 (S4.1) in effect on the date of manufacture. Each of these 
vehicles must have a windshield washing system that meets the 
requirements of FMVSS No. 104 (S4.2.2) in effect on the date of 
manufacture.
    (b) Vehicles manufactured between June 30, 1953, and December 24, 
1968. Each truck, truck-tractor, and bus manufactured between June 30, 
1953, and December 24, 1968, shall be equipped with a power-driven 
windshield wiping system with at least two wiper blades, one on each 
side of the centerline of the windshield. Motor vehicles which depend 
upon vacuum to operate the windshield wipers, shall have the wiper 
system constructed and maintained such that the performance of the 
wipers will not be adversely affected by a change in the intake manifold 
pressure.
    (c) Driveaway-towaway operations. Windshield wiping and washing 
systems need not be in working condition while a commercial motor 
vehicle is

[[Page 430]]

being towed in a driveaway-towaway operation.

[70 FR 48054, Aug. 15, 2005]