Section R13-13-106. Minimum Standards for School Bus Chassis  


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  • The chassis of a school bus introduced to Arizona on or after May 31, 2008 shall meet the requirements of this Section. The chassis of a school bus introduced to Arizona before May 31, 2008 shall meet

    the  requirements   of  this   Section  or  shall  be  maintained   in accordance with the manufacturer’s original specifications.

    will activate when the air loss in the service-brake system reaches 20 to 40 pounds per square inch.

    1.

    Air cleaner: An engine intake air cleaner shall be installed

    g.

    A school bus using a compressed-air or hydraulic-

     

    in the school bus that meets engine specifications defined

     

    assist service-brake system shall be equipped with a

     

    by the school bus manufacturer.

     

    signal located in the school bus driver's compart-

    2.

    Axles: The front and rear axles and suspension assem-

     

    ment  that  emits  a  continuous  audible  or   visible

     

    blies shall have a gross axle weight rating consistent with

     

    warning to the school bus driver when:

     

    that stated by the chassis manufacturer on a notice located

     

    i.      The air pressure available in a compressed-air

     

    in the school bus driver's compartment.

     

    braking system is 60 pounds per square inch or

    3.

    Back-up alarm: If installed, an alarm that emits a warning

     

    less, or

     

    sound when the school bus is backing shall conform to

     

    ii.     There is a loss of fluid flow from the main

     

    the following:

     

    hydraulic pump or loss of electric source pow-

     

    a.      The alarm-signaling device shall be of electronic,

     

    ering the back-up system in a hydraulic-assist

     

    solid state design and shall emit an audible sound of

     

    system.

     

    a minimum of  97 dB(A) measured at  4  feet,

    h.

    A school bus using a compressed-air service-brake

     

    access from the source of the sound.

     

    system shall be equipped with one or two illumi-

     

    b.     The alarm-signaling device shall be wired into the

     

    nated gauges located in the school bus driver's com-

     

    backup light circuits and shall emit sound automati-

     

    partment that show the pounds per square inch of

     

    cally when the gear shift lever is in “reverse” posi-

     

    compressed air available for the operation of the

     

    tion.

     

    brake.

     

    c.      The alarm-signaling device shall be attached to the

    i.

    A compressed-air brake system with a dry reservoir

     

    school bus chassis or body behind the rear axle.

     

    shall have a one-way valve that will prevent the loss

    4.

    Brakes:

     

    of compressed air between the dry reservoir and the

     

    a.      A school bus with a manufacturer-designed passen-

     

    source of compressed air.

     

    ger capacity of 60 or less shall be equipped with a

    j.

    A brake system with a wet reservoir shall have a

     

    service-brake system that uses compressed air or

     

    valve located at the bottom of the wet reservoir that

     

    hydraulic assist.

     

    operates automatically or can be operated remotely

     

    b.     A school bus with a manufacturer-designed passen-

     

    or manually to eject the moisture from the reservoir.

     

    ger capacity greater than 60 shall be equipped with a

    k.

    Compressed-air or hydraulic-assist brake lines and

     

    service- brake system that uses compressed air.

     

    booster-assist lines shall be installed in a manner

     

    c.      In addition to the service-brake system, a school bus

     

    that prevents heat, vibration, and chafing damage.

     

    shall be equipped with a parking-brake system to

    l.

    The brake systems of Types C and D school buses

     

    keep the school bus from moving when parked.

     

    shall be installed so the chassis components can be

     

    d.     The service brakes in a compressed-air system shall

     

    visually inspected to detect brake lining wear with-

     

    be adjusted using the following criteria:

     

    out removal of any of the chassis components.

    Type     Outside Diameter of Air Chamber

    Brake Adjustment Limit

    5.        Front bumper: The front bumper shall be positioned at the forward-most part of the school bus and extend to the outer edges of the school bus.

    6.        Child alert notification system: A school bus may be

    6            4 1/2 inches             1 1/4 inches

    9            5 1/4 inches             1 3/8 inches

    12          5 11/16 inches         1 3/8 inches

    16          6 3/8 inches             1 3/4 inches

    20          6 25/32 inches         1 3/4 inches

    24          7 7/32 inches           1 3/4 inches

    30          8 3/32 inches           2 inches

    36          9 inches                   2 1/4 inches

    e.         The service brakes in a “long stroke” clamp type brake system shall be adjusted using the following criteria:

    equipped with an electronic or mechanical child alert notification system. If a school bus is equipped with a child alert notification system, the device shall be installed in a manner that does not interfere with any other existing operating or electrical component. A child alert notification system in a school bus shall not have an override or bypass capability.

    7.        Clutch: The clutch torque capacity shall be equal to or greater than the engine torque output.

    8.        Color: The chassis, including wheels and front bumper, shall be painted black. The hood and fenders shall be painted National School Bus Yellow as described in R13- 13-107(6).

    Type        Outside Diameter of Air Chamber

    Brake Adjustment Limit

    9.        Cooling system: A school bus shall be equipped with a cooling system that maintains the engine temperature operating range required to prevent damage to the school bus engine.

    12           5 11/16 inches      1 3/4 inches

    16           6 3/8 inches          2 inches

    20           6 25/32 inches      2 inches

    24           7 7/32 inches        2 inches 24*     7 7/32 inches           2 1/2 inches

    30           8 3/32 inches        2 1/2 inches

    *For 3" maximum stroke type 24 chambers

    f.         The service-brake system in a compressed-air sys- tem shall contain an emergency-brake system that

    10.     Drive shaft: Each section of the drive shaft to the rear driving axle shall be protected by a metal guard around its circumference to reduce the possibility of the drive shaft penetrating through the school bus floor or dropping to the ground.

    11.     Electrical system:

    a.         Battery:

    i.         The battery shall have a minimum cold-crank- ing capacity rating equal to the cranking current required by the engine for 30 seconds at F.

    and a minimum reserve capacity rating of 120 minutes at 25 amperes.

    ii.        The battery shall have a higher capacity than specified in subsection (11)(a)(i) if optional equipment installed on the school bus requires the higher capacity.

    iii.      Because all batteries are to be secured in a slid- ing tray in the bus body as required by R13-13- 107, chassis manufacturers shall mount batter- ies temporarily on the chassis frame, except that a van conversion or cutaway front-section chassis may be secured in accordance with the manufacturer's standard configuration. How- ever, in all cases the battery cable provided with the chassis shall have sufficient length to allow some slack, and shall be of sufficient gauge to carry the required amperage.

    b.        Alternator:

    i.         All alternators shall conform to the recom- mended practices of Standard J180, January 2002 (no later amendments or editions) pub- lished by the Society of Automotive Engineers, Inc., 400 Commonwealth Drive, Warrendale, PA 15096-0001, which is incorporated by refer- ence and on file with the Department.

    ii.        All Type A-2 and Type B buses with a GVWR of 15,000 pounds or less shall have an alterna- tor with a minimum of 130 amps.

    iii.      All Type A-2 and Type B buses with a GVWR over 15,000  pounds,  and all Type C and D buses shall be equipped with a heavy-duty truck or bus-type alternator meeting Standard J180, which is incorporated by reference in subsection (b)(i), having a minimum output rat- ing of 130 amps, and shall produce a minimum current output of 50% of the rating at engine idle speed. The alternator may be either pad- mounted or hinge-mounted.

    iv.       Buses equipped with an electrically powered wheelchair lift or air conditioning may be equipped with a device that monitors the elec- trical system voltage and advances the engine idle speed when the voltage drops to, or below, a pre-set level.

    v.        A belt-driven alternator shall be capable of han- dling the rated capacity of the alternator with no detrimental effect on any other driven com- ponents.

    vi.       A direct-drive alternator may be installed instead of a belt-driven alternator.

    vii.     If the school bus is equipped with an air condi- tioning system, the alternator shall have a mini- mum charging rate of 160 amperes per hour.

    viii.    The alternator on a school bus shall contain a regulator to control the voltage to the battery.

    c.         Wiring:

    i.         All wiring shall conform to the recommended practices of Standard J1292, October 1981 (no later amendments or editions), published by the Society of Automotive Engineers, Inc., 400 Commonwealth Drive, Warrendale, PA 15096- 0001, incorporated by reference and on file with the Department.

    ii.        All wiring shall use a standard color or number coding and each chassis shall contain a wiring diagram that details the wiring of the chassis.

    iii.      The chassis shall be equipped with a connec- tion to provide electrical power to the school bus. The connection shall be located on the chassis cowl or on the engine compartment of a school bus designed without a chassis cowl. The connection shall contain terminals for the main 100 ampere body circuit, tail lamps, right- turn signal, left-turn signal, stop lamps, backup lamps, and instrument panel lights. The instru- ment panel lights shall have a rheostat control.

    12.     Engine horsepower: The gross vehicle weight rating of a school bus shall not exceed 185 pounds for each engine horsepower as published by the manufacturer on a notice located on the school bus engine.

    13.     Exhaust system:

    a.         The exhaust pipe, muffler, and tailpipe shall be located under the school bus body and attached to the chassis.

    b.        The tailpipe shall be constructed of corrosion- resistant tubing material at least equal in strength and durability to 16-gauge steel tubing.

    c.         The exhaust system on a gasoline-powered chassis shall be insulated from the fuel tank and fuel tank connections by a shield at any point where the exhaust system is 12 inches or less from the fuel tank or fuel tank connections.

    14.     Frame:

    a.         A school bus frame shall be of a design and strength capable of supporting the gross vehicle weight of the school bus.

    b.        A school bus frame shall not be altered for any pur- pose.

    c.         Holes in top or bottom flanges of frame rails are not permitted except as provided by the manufacturer. There shall be no welding to the frame rails except by the chassis or body manufacturer or the manufac- turer's certified agent.

    d.        The school bus frame shall not be cracked, loose, sagging, or broken.

    e.         Brackets securing the cab or the body of the school bus to the frame shall not be loose, broken, or miss- ing.

    f.         The frame rail flanges shall not be bent, cut, or notched, except as specified by the manufacturer.

    g.        All accessories mounted to the school bus shall be secured as specified by the manufacturer.

    h.        Holes shall not be drilled in the top or bottom rail flanges, except as specified by the manufacturer.

    15.     Front fenders of a Type C school bus: The outer edges of the front fenders shall be wider than the outer edges of the front tires when the front wheels are in the straight-ahead position.

    16.     Fuel system:

    a.         A school bus shall contain a fuel tank with a mini- mum 30-gallon capacity, with a minimum dispersion of 25 gallons of fuel to the engine. The fuel tank shall be vented to the outside of the school bus body so fuel spillage will not contact any part of the exhaust system.

    b.        On a Type B, Type C, or Type D school bus, no por- tion of the fuel system that is located outside of the engine compartment, except the filler tube, shall extend above the top of the chassis frame.

    c.         A fuel filter with replaceable element shall be installed between the fuel tank and engine.

    d.        The fuel line that supplies fuel to the engine shall be located at the top of the fuel tank.

    17.     Horn: A school bus shall be equipped with at least one horn capable of producing a sound level between 82 and 102 dB(A) when tested according to the Standard J377, March 2001 (no later amendments or editions) published by the Society of Automotive Engineers, Inc., 400 Com- monwealth Drive, Warrendale, PA 15096-0001, incorpo- rated by reference and on file with the Department.

    18.     Instruments and instrument panel:

    a.         The chassis shall be equipped with the following instruments:

    i.         Speedometer;

    ii.        Odometer  that  will give  accrued  mileage to seven digits, including tenths of miles;

    iii.      Voltmeter or ammeter;

    iv.       Oil pressure gauge;

    v.        Water temperature gauge;

    vi.       Fuel gauge;

    vii.     Upper beam head lamp indicator;

    viii.    Brake system signal as required by R13-13- 106(4)(f);

    ix.       Turn signal indicator; and

    x.        Air pressure or hydraulic gauge.

    b.        The instruments shall be mounted on the instrument panel in the school bus driver's compartment and visible to the school bus driver while seated in the driver's seat.

    c.         The instrument panel shall be equipped with a rheo- stat switch that controls the illumination to the instrument panel and the gear shift selector indica- tor.

    19.     Oil filter: A replaceable element or cartridge-type oil fil- ter shall be provided with a minimum capacity that meets or exceeds the capacity recommended by the manufac- turer of the school bus engine.

    20.     Openings: All openings in the floorboard and in the fire wall between the chassis and passenger  compartment shall be sealed.

    21.     Splash guards:

    a.         A school bus shall be equipped with rear fender splash guards constructed of flexible rubberized material.

    b.        The splash guards shall be wide enough to cover the tire tread width, installed close enough to the tire tread surface to control side-throw of road surface material, and extend to within 8 inches of ground level.

    22.     Steering system:

    a.         Power steering is required on all school buses manu- factured after January 1, 1984.

    b.        Bracing extending from the center of the steering wheel to the steering wheel ring shall not be cracked or missing.

    c.         The distance of movement of the steering wheel between two points of resistance shall not be greater than the following when measured with the engine running:

    d.        There shall be clearance of at least 2 inches between the steering wheel and any object in the driver's compartment.

    e.         A non-adjustable steering column shall be fastened in a fixed position. An adjustable steering column shall be equipped with a locking mechanism.

    f.         The steering gear housing shall not have loose or missing mounting bolts. There shall not be cracks in the gear housing or its mounting brackets.

    g.        The connecting arm on the steering gear power source shall not be loose.

    h.        The steering wheel shall turn freely in both direc- tions.

    i.         The steering system shall have a means for lubrica- tion of all wear-points.

    23.     Suspension:

    a.         Shock absorbers:

    i.         A school bus shall be equipped with front and rear double-acting shock absorbers. Replace- ments to shock absorbers shall be made accord- ing to the specifications of the manufacturer's part number as stamped on the shock absorber.

    ii.        If a school bus is manufactured with tandem rear axles, rear shock absorbers are not required.

    b.        Suspension system:

    i.         Capacity of suspension assemblies shall be commensurate with the chassis manufacturer's gross vehicle weight rating.

    ii.        If leaf-type rear springs are used, they shall be a progressive rate or multi-stage design.

    24.     Tires and wheels:

    a.         Tires and wheels shall have an accumulated load rat- ing at least equal to the gross vehicle weight rating.

    b.        Dual rear tires shall be provided on all school buses that have a gross vehicle weight rating of more than 10,000 pounds.

    c.         Each tire on a particular axle shall be the same size.

    d.        All tires on a school bus shall be bias or all tires on a school bus shall be radial and shall not differ more than one size between front and rear axles.

    e.         On a Type C or D school bus, a spare tire, if present, shall be in a carrier mounted outside the passenger compartment.

    25.     Transmission: The school bus transmission shall have no fewer than three forward speeds and one reverse speed.

    26.     Turning radius:

    a.         A chassis with a wheelbase of 264 inches or less shall have a right and left turning radius of not more than 42 1/2 feet, as measured to the edge of the front tire at the outside of a circle as the school bus moves within the circle.

    b.        A chassis with a wheelbase of more than 264 inches shall have a right and left turning radius of not more than 44 1/2 feet, as measured to the edge of the front tire at the outside of a circle as the school bus moves within the circle.

    27.     Weight:

    Steering wheel diameter

    Power steering

    Manual steering

    a.         The gross vehicle weight of a school bus shall not exceed the chassis manufacturer's gross vehicle weight rating for the chassis as recorded on a notice

    16 in. or less          6 3/4 inches       4 1/2 in.

    18 in.                     7 1/8 inches       4 3/4 in.

    20 in.                     7 7/8 inches       5 1/4 in.

    22 in.                     8 5/8 inches       5 3/4 in.

    located in the school bus driver's compartment.

    b.        To calculate the gross vehicle weight of a school bus, add the chassis weight, the school bus body weight, the school bus driver's weight, and the total seated passenger weight.

    i.         For the purpose of calculation, the school bus driver's weight is 150 pounds.

    ii.        For the purpose of calculation, the passenger weight is 120 pounds per seated passenger.

    c.         The weight distribution of a school bus on a level surface that is fully loaded according to the gross vehicle weight rating shall not exceed the front axle gross weight rating or rear axle gross weight rating as recorded on a notice located in the school bus driver's compartment.

Historical Note

Adopted effective February 16, 1996 (Supp. 96-1).

Amended by final rulemaking at 7 A.A.R. 2906, effective June 13, 2001 (Supp. 01-2). Amended by final rulemak-

ing at 14 A.A.R. 2110, effective May 8, 2008 (Supp. 08- 2). New Section R13-13-106 recodified from R17-9-106 with Section cross-references revised, at 20 A.A.R. 2083, effective July 25, 2014 (Supp. 14-3). Amended by final

rulemaking at 21 A.A.R. 3211, effective January 24, 2016

(Supp. 15-4).