N.M. Admin. Code § 6.40.2.9

Current through Register Vol. 35, No. 23, December 10, 2024

Section 6.40.2.9 - BUS CHASSIS STANDARDS

A. AIR CLEANER

(1) The engine intake air cleaner system shall be furnished and properly installed by the chassis manufacturer to meet engine manufacturer's specifications.

(2) All diesel engine air filters shall include a restriction indicator of the latching type that retains the maximum restriction developed during operation of the engine. The indicator should include a reset control so the indication can be returned to zero when desired.

B. ALTERNATIVE FUELS

(1) Chassis shall meet all BUS CHASSIS STANDARDS.

(2) Chassis shall meet all applicable 49 CFR 571 federal motor vehicle safety standards (FMVSS).

C. AXLES: The front and rear ends, including suspension assemblies, shall have a gross axle weight rating at ground at least equal to that portion of the load as would be imposed by the chassis manufacturer's maximum gross vehicle weight rating.

D. BRAKES

(1) The braking system shall include the service brake and a parking emergency brake.

(2) Buses using air in the operation of the brake system shall be equipped with warning signals, readily audible and visible to the driver, that will give a continuous warning when the air pressure available in the system for braking is 60 psi (pounds per square inch) or less. An illuminated gauge shall be provided that will indicate to the driver the air pressure in pounds per square inch for the operation of the brakes.

(3) Any brake system with a dry reservoir shall be equipped with a check-valve or equivalent device to ensure that in the event of failure or leakage in its connection to the source of compressed air, the stored dry air shall not be depleted by the leakage or failure.

(4) Buses using a hydraulic-assist brake shall be equipped with warning signals, readily audible and visible to the driver, that will provide continuous warning in the event of a loss of fluid flow from primary source and in the event of discontinuity in that portion of the vehicle electrical system that supplies power to the backup system.

(5) The brake lines and booster-assist lines shall be protected from excessive heat and vibration and installed in a manner, which prevents chafing.

(6) All brake systems shall be designed to permit visual inspection of brake lining wear without removal of any chassis components.

(7) All type C and type D school buses shall be equipped with air brakes.

E. BUMPER, FRONT

(1) All school buses shall be equipped with a front bumper. The front bumper shall be furnished by the chassis manufacturer as part of the chassis on all types of chassis unless there is a specific arrangement between the chassis manufacturer and body manufacturer that the body manufacturer will furnish the front bumper.

(2) Unless energy absorbing bumper is used, the front bumper shall be of pressed steel channel or equivalent material at least 3/16-inch thick and not less than 8-inch wide (high) and shall extend beyond forward-most part of the body, grille, hood, and fenders and shall extend to outer edges of the fenders at the bumper's top line.

(3) Front bumper, except breakaway bumper ends, shall be of sufficient strength to permit pushing a vehicle of equal gross vehicle weight without permanent distortion to the bumper, chassis, or body.

(4) If tow eyes or hooks are furnished they shall be attached so as not to project beyond the front bumper. Tow eyes or hooks attached to the frame chassis may be furnished by the chassis manufacturer. This installation shall be in accordance with the chassis manufacturer's standards.

(5) The bumper shall be designed or reinforced so that it will not deform when the bus is lifted by a chain that is passed under the bumper (or through the bumper if holes are provided for this purpose) and attached to both tow eyes. For the purpose of meeting this standard, the bus shall be empty and positioned on a level, hard surface and both tow eyes shall share the load equally.

(6) The exhaust system on vehicles equipped with a power lift unit may be routed to the left of the right frame rail to allow for the installation of a power lift unit on the right side of the vehicle.

F. CLUTCH

(1) Clutch torque capacity shall be equal to or greater than the engine torque output.

(2) A starter interlock shall be installed to prevent actuation of the starter if the clutch is not depressed.

G. COLOR

(1) Chassis, including wheels and front bumper, shall be black. Body cowl, hood, and fenders shall be in national school bus yellow. The flat top surface of the hood may be non-reflective national school bus yellow. Activity school buses may be team colors.

(2) Demountable rims, if used, may be, silver, gray or black as received from the wheel manufacturer. Wheels may be polished aluminum, chrome or of a team color on activity buses only.

H. COOLING SYSTEMS (ENGINE): Engine cooling system shall be sufficient capacity to properly maintain engine-operating temperature to manufactures specifications at the rated horsepower.

I. DRIVE SHAFT: Drive shafts shall be protected by a metal guard or guards around the circumference of the drive shafts to reduce the possibility of its whipping through the floor or dropping to the ground if broken.

J. ELECTRICAL SYSTEM

(1) Battery

(a) Storage battery shall have minimum cold cranking capacity rating equal to the cranking current required for 30 seconds at 0 degrees Fahrenheit (-17.8°C) and a minimum reserve capacity rating of 120 minutes at 25 amps. Higher capacities may be required depending upon optional equipment and local environmental conditions.

(b) Since all batteries are to be secured in a sliding tray in the body, chassis manufacturers shall temporarily mount the battery on the chassis frame, except that van conversion or cutaway front-section chassis may be manufacturer's standard configuration. In these cases, the final location of the battery and the appropriate cable lengths shall be according to the design objectives, or as mutually agreed upon by the chassis and body manufacturer. In all cases, however, the battery cable provided with the chassis shall have sufficient length to allow some slack. Battery storage area shall be secured with a locking system or release system that shall be accessible from the driver's compartment.

(2) Alternator

(a) All type A-II buses up to 15,000 lbs. GVWR shall have a minimum 60-ampere alternator.

(b) Types A-II buses over 15,000 lbs. GVWR and all types C and D buses shall be equipped with a heavy-duty truck or bus-type alternator, having a minimum output rating of 130 amperes. Alternators of 130 through 145-ampere design shall produce a minimum of 50 percent amperes output at engine idle speed.

(c) All buses equipped with an electrical power lift shall have a minimum 130-ampere alternator.

(d) Direct-drive alternator is permissible in lieu of belt drive. Belt drive shall be capable of handling the rated capacity of the alternator with no detrimental effect on other driven components.

(3) Wiring

(a) All wiring shall conform to current applicable recommended practices of the society of automotive engineers (SAE). All wiring shall use a standard color and number coding and each chassis shall be delivered with a wiring diagram that illustrates the wiring of the chassis.

(b) Chassis manufacturer shall install a readily accessible terminal strip or plug on the body side of the cowl, or in an accessible location in the engine compartment of vehicles designed without a cowl, that shall contain the following terminals for the body connections:

(i) main 130 amp body circuit

(ii) tail lamps

(iii) right turn signal

(iv) left turn signal

(v) stop lamps

(vi) back up lamps

(vii) instrument panel lights (rheostat controlled by headlamp switch)

(4) Circuits

(a) An appropriate identifying diagram (color and number coded) for electrical circuits shall be provided to the body manufacturer for distribution to the end user.

(b) Headlight system must be wired separately from the body-controlled solenoid.

(5) Daytime running light

(a) Exterior low-beam headlights and taillights may be provided with a switch to automatically operate said lamps when the vehicle's ignition is engaged. This switch, if furnished, shall not engage while the starter is engaged. If this switch designed to provide reduced illumination under normal operating conditions, a means whereby the headlights and taillights can be engaged at full power shall be provided.

(b) Chassis manufacturer shall provide a means for body manufacturer to include the taillights in the daytime running light (DRL) circuit.

K. ENGINE FIRE EXTINGUISHER (optional equipment): Manufacturer may provide an automatic fire extinguisher system in the engine compartment.

L. EXHAUST SYSTEM

(1) Exhaust pipe, muffler and tailpipe shall be outside the bus body compartment and attached to the chassis so as not to damage any other chassis component.

(2) Tailpipe shall be constructed of a corrosion-resistant tubing material at least equal in strength and durability to 16-gauge steel tubing.

(3) Chassis manufacturers shall furnish an exhaust system with tailpipe of sufficient length to exit the rear of the bus at the left side of the bus body no more than 18-inches forward of the front edge of the rear wheelhouse opening. If designed to exit at the rear of the bus, the tailpipe shall extend at least five inches beyond the end of the chassis frame. If designed to exit to the side of the bus, the tailpipe shall extend at least 48.5-inches (51.5-inches if the body is to be 102-inches wide) outboard from the chassis centerline.

(a) On types C and D vehicles, the tailpipe shall not exit beneath a fuel fill or emergency door exit.

(b) Type A chassis may be furnished with the manufacturer's standard tailpipe configuration.

(4) Exhaust system on a chassis shall be properly insulated from the fuel tank connections by securely attached metal shield at any point where it is 12-inches or less from tank or tank connection.

(5) Muffler shall be constructed of corrosion-resistant material.

M. FENDERS, FRONT-TYPE C VEHICLES

(1) Total spread of outer edges of front fenders, measured at fender line, shall exceed total spread of front tires when front wheels are in straight-ahead position.

(2) Front fenders shall be properly braced and free from any body attachments.

N. FRAME

(1) Frame or equivalent shall be of such design and strength characteristics as to correspond at least to standard practice for trucks of the same general load characteristics which are used for highway service.

(2) Any secondary manufacturer that modifies the original chassis frame shall guarantee the performance of workmanship and materials resulting from such modification.

(3) Frames shall not be modified for the purpose of extending the wheelbase.

(4) Holes in top or bottom flanges or side units of the frame, and welding to the frame, shall not be permitted except as provided or accepted by chassis manufacturer.

(5) Frame lengths shall be provided in accordance with design objectives, except where body and chassis manufacturer are the same or have established mutual design criteria for the vehicle.

O. FUEL TANK

(1) Fuel tank or tanks having a minimum 30-gallon capacity with a 25-gallon actual draw shall be provided by the chassis manufacturer. The tank shall be filled and vented to the outside of the body, in a location where accidental fuel spillage will not drip or drain on any part of the exhaust system. Vehicles with a wheel base of 193-inches and larger shall be equipped with fuel tank or tanks of minimum 60-gallon capacity with a 50-gallon actual draw.

(2) No portion of the fuel system, which is located outside the engine compartment, except the filler tube, shall extend above the top of the chassis frame rail. Fuel lines shall be mounted to obtain maximum possible protection from the chassis frame.

(3) Fuel filter with replaceable element shall be installed between the fuel tank and engine.

(4) Fuel tank installation shall be in accordance with design objectives and all federal motor vehicle safety standards in effect on the date of manufacture of the bus. Fuel tank(s) may be mounted between the chassis frame rails or outboard of the frame rails on either the left or right side of the vehicle.

(5) The actual draw capacity of each fuel tank shall be 83% of the tank capacity.

(6) Unless specific agreement has been made between the body and chassis manufacturers, fuel tanks and filler spouts shall not be located in spaces restricted by design objectives.

(7) Installation of alternative fuel systems, including fuel tanks and piping from tank to engine, shall comply with all applicable fire codes and applicable federal motor vehicle safety standards in effect on the date of manufacture of the bus. Installation of LPG tanks shall comply with national fire protection association (NFPA) 58.

P. HEATING SYSTEM: The chassis engine shall have plugged openings for the purpose of supplying hot water for the bus heating system. The openings shall be suitable for attaching 3/4-inch pipe thread/hose connector. The engine shall be capable of supplying water having a temperature of at least 170 degrees Fahrenheit at a flow rate of 50 pounds/per minute at the return end of 30 feet of one inch inside diameter automotive hot water heater hose. (School Transportation Manufacturing Technical Committee Standard No. 001 - Standard Code for Testing and Rating Automotive Bus Hot Water Heating and Ventilating Equipment.)

Q. HORN: Bus shall be equipped with horn or horns of standard make with each horn capable of producing a complex sound in bands of audio frequencies between 250 and 2,000 cycles per second and tested in accordance with SAE J-377.

R. INSTRUMENTS AND INSTRUMENT PANEL

(1) Chassis shall be equipped with the following instruments and gauges. (lights in lieu of gauges are not acceptable, except as noted):

(a) speedometer;

(b) odometer which will give accrued mileage (to seven digits), including tenths of miles;

(c) voltmeter; ammeter with graduated charge and discharge, with ammeter and its wiring compatible with generating capacities, is permitted in lieu of voltmeter;

(d) oil pressure gauge;

(e) water temperature gauge;

(f) fuel gauge;

(g) upper beam headlight indicator light;

(h) brake indicator gauge light indicator in lieu of gauge is permitted on vehicle equipped with hydraulic-over-hydraulic brake system;

(i) turn signal indicator light;

(j) start indicator light where appropriate.

(2) All instruments shall be easily accessible for maintenance and repair.

(3) Instruments and gauges shall be mounted on the instrument panel so that each is clearly visible to the driver while seated in a normal driving position.

(4) Instrument panel shall have lamps of sufficient candlepower to illuminate all instruments and gauges and shift selector indicator for automatic transmission.

(5) Multi-function gauge (MFG)

(a) The driver must be able to manually select any displayable function of the gauge on a MFG whenever desired.

(b) Whenever an out-of-limits conditions occurs, which would be displayed on one or more functions of a MFG, then the MFG controller should automatically display this condition on the instrument cluster. This should be in the form of an illuminated tell-tale warning light as well as having the MFG automatically display the out-of-limits indications. Should two or more functions displayed on the MFG go out-of-limits simultaneously, then the MFG should automatically sequence between those functions continuously until the condition(s) is corrected.

(c) The use of a MFG does not relieve the requirements for audible warning devices, where required.

S. OIL FILTER: An oil filter with a replaceable element shall be provided and connected by flexible oil lines if not a built-in or an engine-mounted design. The oil filter shall have a capacity of at least one (1) quart.

T. OPENINGS: All openings in the floorboard or firewall between chassis and passenger compartment, such as for gearshift selector and parking brake lever, shall be sealed.

U. PASSENGER LOAD

(1) Actual gross vehicle weight (GVW) is the sum of the chassis weight, plus the body weight, plus the driver's weight, plus total seated pupil weight.

(a) For purposes of calculation, the driver's weight is 150 pounds.

(b) For purposes of calculation, the pupil weight is 120 pounds per pupil.

(2) Actual gross vehicle weight (GVW) shall not exceed the chassis manufacturer's GVWR for the chassis nor shall the actual weight carried on any axle exceed the chassis manufacturer's GVWR.

(3) Manufacturer's (GVWR) shall be furnished in duplicate (unless more are requested) by manufacturers to the state agency having pupil transportation jurisdiction. The state agency shall, in turn, transmit such ratings to other state agencies responsible for development or enforcement of state standards for school buses.

V. POWER AND GRADE ABILITY: Shall not exceed the manufacturer's recommended standards for the vehicle size. A maximum speed limiter shall be set at 75 miles per hour. A lower setting is permissible at the request of the school bus owner. A cruise control mechanism may be installed on school activity buses only.

W. RETARDER SYSTEM (OPTIONAL EQUIPMENT): Retarder system, if used, shall maintain the speed of the fully loaded school bus at 19.0 mph or 30 km/hr on a 7% grade for 3.6 miles or 6 km.

X. SHOCK ABSORBERS: The bus shall be equipped with double-action shock absorbers compatible with manufacturer's rated axle capacity at each wheel location.

Y. STEERING GEAR

(1) The steering gear shall be approved by the chassis manufacturer and designed to ensure safe and accurate performance when the vehicle is operated with maximum load and at maximum speed.

(2) If external adjustments are required, steering mechanism shall be accessible to accomplish same.

(3) No changes shall be made in the steering apparatus, which are not approved by the chassis manufacturer.

(4) There shall be a clearance of at least 2-inches between the steering wheel and cowl, instrument panel, windshield, or any other surface.

(5) Power steering is required and shall be of the integral type with integral valves.

(6) The steering system shall be designed to provide a means for lubrication of all wear-points, if wear-points are not permanently lubricated.

Z. SUSPENSION SYSTEM: A soft ride suspension system, (taper leaf) low friction parabolic springs, vari-rate and two stage steel leaf rear springs shall be provided on type C and D buses where lift equipment is required.

(1) The capacity of springs or suspension assemblies shall be commensurate with chassis manufacturer's GVWR rating.

(2) Leaf rear springs shall be a progressive rate or multi-stage design. Front leaf springs shall have a stationary eye at one end and shall be protected by wrapped leaf in addition to the main leaf.

AA. THROTTLE: The force required to operate the throttle shall not exceed 16 pounds throughout the full range of accelerator pedal travel.

BB. TIRES AND RIMS

(1) Tires and rims of the proper size and tires with a load rating commensurate with chassis manufacturer's gross vehicle weight rating shall be provided. The use of multi-piece rims and/or tube-type tires shall not be permitted on any school bus ordered after the effective date of these standards. Rims on activity buses may be chrome or of a team color.

(2) Dual rear tires shall be provided on type A-II, type C, and type D school buses.

(3) All tires on a vehicle shall be of the same size, and the load range of the tires shall meet or exceed the GVWR as required by 49 CFR 571.120(FMVSS).

(4) If the vehicle is equipped with a spare tire and rim assembly, it shall be the same size as those mounted on the vehicle.

(5) If a tire carrier is required, it shall be suitably mounted in an accessible location outside the passenger compartment. Exception: On type A vehicles, spare tire and carrier may be mounted behind the last seat at the rear of the bus if adequately secured and mounted in such a way as not to interfere with the emergency exit.

CC. TRANSMISSION

(1) Automatic transmissions shall have no fewer than three forward speeds and one reverse speed. The shift selector shall provide a detent between each gear position when the gear selector quadrant and shift selector are not steering column mounted.

(2) In manual transmissions, second gear and higher shall be synchronized except when incompatible with engine power. A minimum of three forward speeds and one reverse speed shall be provided.

(3) An electronic control or similar device may be installed to ensure that automatic transmissions cannot accidentally be moved out of the neutral or park gear position while the driver is not in the driver's seat.

(4) A two-speed axle is not permitted.

DD. TURNING RADIUS

(1) 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, curb to curb measurement.

(2) A chassis with a wheelbase of 265-inches or more shall have a right and left turning radius of not more than 44 1/2 feet, curb to curb measurement.

EE. UNDERCOATING: The chassis manufacturers or their agent shall coat the undersides of steel or metallic-constructed front fenders with a rust-proofing compound for which compound manufacturers have issued notarized certification of compliance to chassis builder that the compound meets or exceeds all performance and qualitative requirements using modified tests.

FF. VEHICLE INTERLOCK SYSTEM: School buses equipped with a power lift shall meet 49 CFR 571.403 and 571.404(FMVSS).

N.M. Admin. Code § 6.40.2.9

7-01-96; 6.40.2.9 NMAC - Rn, 6 NMAC 9.2.10 & A, 7-31-2000; A, 07-15-2003; A, 11-15-2005; A, 12-30-2010