§393.41 Parking Brake Systems

Question 1: May the "park" position of a CMV's transmission be used as a parking brake to comply with the §393.41?

Guidance: No. The "park" position of the transmission is only a locking device used to lock the transmission.

Question 2: Does §393.41 prohibit air brake systems from being equipped with a means to release the spring brakes for purposes of towing disabled vehicles in emergency situations?

Guidance: No, provided the brakes are designed and maintained so they cannot be released unless adequate energy is available to make immediate reapplication of the brakes when the brake system is operable.

Question 3: Are parking brakes required on every CMV manufactured before March 7, 1990?

Guidance: No.