[Code of Federal Regulations] [Title 49, Volume 4] [Revised as of October 1, 2002] From the U.S. Government Printing Office via GPO Access [CITE: 49CFR393.46] [Page 1067] TITLE 49--TRANSPORTATION CHAPTER III--FEDERAL MOTOR CARRIER SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION PART 393--PARTS AND ACCESSORIES NECESSARY FOR SAFE OPERATION--Table of Contents Subpart C--Brakes Sec. 393.46 Brake tubing and hose connections. All connections for air, vacuum, or hydraulic braking systems shall: (a) Be adequate in material and construction to insure proper continued functioning; (b) Be designed, constructed, and installed so as to insure, when properly connected, an attachment free of leaks, constrictions, or other defects; (c) Have suitable provision in every detachable connection to afford reasonable assurance against accidental disconnection; (d) Have the vacuum brake engine manifold connection at least three- eighths inch in diameter. (e) If installed on a vehicle on or after January 1, 1981, meet requirements under applicable subsections of FMVSS 106 (49 CFR 571.106). (f) Splices in tubing if installed on a vehicle after March 7, 1989, must use fittings that meet the requirements of SAE Standard J512-OCT 80 Automotive Tube Fittings or for air brake systems SAE J246--March 81 Spherical and Flanged Sleeve (Compression) Tube Fittings as found in the SAE Handbook 1985 edition. [33 FR 19735, Dec. 28, 1968, as amended at 44 FR 25457, May 1, 1979; 53 FR 49400, Dec. 7, 1988]