Current through Register 2024 Notice Reg. No. 38, September 20, 2024
The following additional brake requirements shall apply to
school buses and farm labor vehicles:
(a) Air Brakes--Type 1 school buses having 10
or more rows of seats and manufactured after January 1, 1970, and prior to
April 1, 1977, shall be equipped with full compressed air brakes. Type 1 school
buses equipped with air brakes and manufactured after January 1, 1953, shall
have at least two reservoirs connected in series. On all school buses
manufactured on or after July 1, 1970, the air-actuated devices outside the
service and emergency brake systems shall also be provided with a reservoir
equal to at least six times the total volume at full travel of all auxiliary
devices supplied by the reservoir. The reservoir requirement for the
air-actuated devices outside the service and emergency brake systems shall not
apply to school buses manufactured on or after March 1, 1975, in compliance
with FMVSS 121 (49 CFR
571.121).
(b) Warning Devices--Type 1 school bus brake
systems shall have warning devices as follows:
(1) Air brakes shall have a buzzer or other
audible warning signal and a visual, air-operated, flag-type warning device,
both used exclusively for the brake system. Both devices shall give a
continuous warning when the air supply pressure in the first reservoir to
receive air from the compressor, or any service reservoir, drops below a fixed
pressure as specified by Vehicle Code Section 26506. The flag-type device is
not required on vehicles manufactured on or after March 1, 1975, in compliance
with FMVSS 121 (49 CFR
571.121).
(2) Vacuum brakes shall have a buzzer or
other audible warning signal and a visual, vacuum-operated, flag-type warning
device, both used exclusively for the brake system. They shall provide
continuous warning to the driver when the vacuum in the supply system drops to
8 inches of mercury and less. The requirement for the flag device shall not
apply to vehicles manufactured with a dual or split type service brake system
powered by power-assist vacuum chambers.
(3) The visual warning devices required in
(1) and (2) shall be readily visible to the driver when seated in the normal
driving position.
(4) Override
switches are prohibited for audible warning devices required in (1) and
(2).
(5) The requirements in (1)
and (2) for warning devices to be used exclusively for the brake system shall
not be construed to prohibit multichannel warning devices that monitor other
vehicle systems in addition to the brake system if such devices provide a clear
brake system warning that cannot be activated by any of the other monitored
vehicle systems.
(c)
Brake System Modification--Brakes on Type 1 school buses may be modified only
with the written approval of the school bus chassis manufacturer or by using
brake system options of a type available from the bus manufacturer and
represented by the bus manufacturer as suitable for use on the specific model
school bus. Modifications shall not render the brake system in violation of the
provisions of this title or of any other law or regulation. Modifications shall
not render inoperative any item of brake-related equipment nor diminish any
aspect of performance of a brake system manufactured in compliance with FMVSS
121, except as permitted by written ruling of the National Highway Traffic
Safety Administration.
(1) Air system cleaning
devices, such as automatic condensate drains and air dryers, are not considered
a modification of the brake system if they are installed in accordance with the
component manufacturer's instructions.
(2) A conversion from an air brake chamber
that has an air applied parking brake or emergency stopping system function to
a brake chamber that has a spring applied parking brake or emergency stopping
system function, or vice versa, is not considered a modification if the
conversion is made in accordance with the substitute component manufacturer's
instructions.
(3) Any advisory
recommendations by the component manufacturer shall be considered mandatory.
The instructions shall be retained by the school bus operator for reference by
California Highway Patrol personnel for comparison with the completed
installations.
(d)
Service Brake System--Type 1 school buses manufactured on and after January 1,
1968, shall comply with the following requirements:
(1) Foot Pedal Travel--The travel of
hydraulic brake foot pedals shall not exceed 60 percent of the available travel
when measured statically at the minimum pedal force required for compliance
with Vehicle Code Sections 26454 on stopping distance.
(2) Air or Vacuum Reservoirs--The combined
volume of all service reservoirs shall be at least 12 times the combined volume
of all service brake chambers at maximum travel of the pistons or
diaphragms.
(3) Check Valves--Brake
systems safeguarded by the check valve referenced in Section
1245(b) of this
title shall meet the following requirements:
(A) Air Brake System--At least half of the
required air reservoir capacity shall be safeguarded to prevent the stored air
from being depleted by any failure or leakage in the connection to the source
of compressed air. Air supply for the service brakes shall be protected so that
failure of the air-actuated devices outside the service brake system will not
drop the service brake supply system pressure to less than 60 pounds per square
inch.
(B) Vacuum Brake System--The
required vacuum brake system reservoir capacity shall be safeguarded to prevent
the stored vacuum from being depleted by any failure or leakage in its
connection to the source of vacuum. The supply of vacuum for all devices or
systems other than the brake system shall be drawn from between the brake
system check valve and the source of vacuum.
(e) Emergency Stopping System--Type 1 school
buses manufactured after January 1, 1968, shall comply with the following
emergency stopping system requirements:
(1)
The brakes shall be capable of being applied, released, and reapplied by the
driver but shall not be capable of being released from the driver's seat after
any reapplication unless energy is available for an immediate
reapplication.
(2) The brakes shall
be manually applied and released under modulated control by the driver to
maintain directional stability during a complete emergency stop.
(3) Failure or malfunction of any part in
either the emergency stopping system or the service brake system shall not
leave the vehicle without operative brakes capable of stopping the vehicle
loaded up to the manufacturer's gross vehicle weight rating within the
requirements of California Vehicle Code Section 26508(k)(3).
This provision does not apply to a failure in the
mechanical parts of the wheel brake assemblies or the brake pedal and linkage
to the brake valve or master cylinder.
(4) School buses manufactured on or after
March 1, 1975, in compliance with FMVSS 121 (49 CFR 571.121) and
maintained in compliance with that standard, shall be deemed in compliance with
this subsection.
(f)
Reservoir Capacity--The reservoir capacity of school buses and farm labor
vehicles shall be sufficient to complete one operation of the doors after the
engine has stopped and the brakes have been fully applied.
1. Amendment
of subsections (b)(2) and (d)(3)(A) filed 6-9-82; effective thirtieth day
thereafter (Register 82, No. 24).
2. Amendment of subsection (b)(1)
filed 4-16-86; effective thirtieth day thereafter (Register 86, No.
16).
3. Repealer and new section filed 5-14-92; operative 6-15-92
(Register 92, No. 20).
4. Editorial correction of printing error in
subsection (e)(3) (Register 92, No. 29).
5. Change without
regulatory effect amending subsection (d)(3)(B) and NOTE filed 5-11-95 pursuant
to section 100, title 1, California Code of
Regulations (Register 95, No. 19).
Note: Authority cited: Sections 31401 and 34508, Vehicle
Code. Reference: Sections 31401 and 34508, Vehicle
Code.
