N.J. Admin. Code § 13:20-33.47

Current through Register Vol. 56, No. 24, December 18, 2024

Section 13:20-33.47 - Commercial vehicle inspection: service brakes (including service brake equalization and service brake pedal reserve

(a) The inspection for motor vehicle service brake pedal reserve shall be performed as set forth in this section. "Pedal reserve" is the amount of total pedal travel left in reserve when the pedal is depressed to the brake applied position. The service brake pedal reserve test does not apply to air brake systems.

(b) With the motor vehicle stationary and the service brake pedal depressed under a moderate foot force (that is, a force of 25 pounds for power brakes and 50 pounds for other brakes), there shall be a minimum of one-fifth of the total average pedal travel (as per the motor vehicle manufacturer's specifications) remaining. The motor vehicle engine shall be running when power brakes are tested. In the event that the adequacy of the service brake pedal reserve on a motor vehicle equipped with disc brakes is in question, the pedal reserve shall be tested when the brakes are applied while the motor vehicle is being driven. The service brake pedal reserve test is not required for motor vehicles equipped with full power (central hydraulic) brake systems or for motor vehicles with brake systems designed to operate with less than one-fifth pedal travel.

(c) With the service brake pedal depressed to the brake applied position for 10 seconds under a foot force of approximately 125 pounds, there shall be no perceptible decrease in pedal height and, if the motor vehicle is so equipped, no illumination of the brake system failure indicator light. If a motor vehicle is so equipped, the brake system failure indicator light shall be in proper operating condition.

(d) Brake hoses shall not be mounted so as to contact the vehicle body or chassis. Brake hoses shall not be cracked, chafed, or flattened. Protective devices, such as "rub rings," are not to be considered part of the brake hose.

(e) Hydraulic or air brake line tubing shall be specially designed for automotive hydraulic or air brake line use. Tubing designed for gasoline or oil lines is not acceptable for use as hydraulic or air brake lines.

(f) If the motor vehicle inspection report indicates that a motor vehicle was previously rejected for service brakes or service brake equalization, at least one front wheel of the motor vehicle shall be removed so that it can be determined whether the internal parts of the brake are in proper condition. Any wear, breakage, or malfunctioning of the brake system which would adversely affect the safe operation of the motor vehicle shall be cause for rejection.

(g) The brake drum diameter or disc brake rotor thickness shall be measured. If the brake drum is embossed with a maximum safe diameter dimension or the brake rotor is embossed with a minimum safety thickness dimension, the drum or disc shall be within such specification. These dimensions will be found on motor vehicles manufactured after January 1, 1971, and may be found on motor vehicles manufactured prior to that date. If the drums and discs are not so embossed, the drums and discs shall be within the manufacturer's specifications.

(h) The brake lining or pad shall be visually examined, and the height of the rubbing surface of the lining or pad over the rivet heads shall be measured. The bonded lining or bonded pad thickness over the shoe surface shall be measured at the thinnest point of the lining or pad.

(i) The thickness of a riveted lining or pad on each brake shall be not less than 1/32 of an inch over the rivet heads. The thickness of a bonded lining or pad shall be not less than 1/32 of an inch over the brake shoe or shoe plate. Brake linings and pads shall not have cracks or breaks that extend to rivet holes except minor cracks that do not impair attachment. Drum brake linings shall be securely attached to brake shoes. Disc brake pads shall be securely attached to shoe plates.

(j) Backing plates and caliper assemblies shall not be deformed or cracked. Brake system parts shall not be broken, misaligned, missing, binding, or show evidence of severe wear. Automatic adjusters and other parts shall be assembled properly and installed correctly.

(k) The vacuum brake hoses shall be examined visually and aurally with the motor vehicle engine running. The hoses shall not be collapsed, abraded, broken, improperly mounted, or audibly leaking.

(l) The motor vehicle engine shall be turned off and the service brake applied several times to destroy vacuum in the system. The brake pedal shall be depressed with 25 pounds of force and, while maintaining such force, the engine started. The brake pedal shall fall slightly under force when the engine starts. This test is not applicable to motor vehicles equipped with full power (central hydraulic) brake systems, as the service brake performance test shall be considered an adequate test of system performance for such motor vehicles.

(m) After insuring that the tires are properly inflated, a Type 1, Type 2, or Type 3 brake performance test shall be conducted:

1. Type 1: If the brakes are tested on a drive-on platform or roller-type brake tester, the results shall show some brake force produced by each wheel brake and the total brake force shall be equal to at least 43.5 percent of the gross vehicle weight. This is equivalent to a deceleration of 14 feet per second, which shall produce a stop from a speed of 20 miles per hour in 30 feet. The braking force on a front wheel or on a rear wheel shall not be less than 65 percent of the braking force developed on the other front wheel or rear wheel, respectively. The service brake shall have a minimum front to rear brake ratio of 40 percent and a maximum front to rear brake ratio of 95 percent. The allowable front brake bias margin shall be 25 percent. The allowable rear brake bias margin shall be 15 percent, except that for motor vehicles having a GVWR of 7,000 pounds or more but less than 10,001 pounds, the allowable rear brake bias margin shall be 25 percent.

2. Type 2: The brakes may be tested with an approved accelerometer/inertia navigation type tester to determine whether the motor vehicle can stop from a speed of 20 miles per hour in 30 feet.

3. Type 3: If a drive-on platform brake tester or roller-type brake tester or an accelerometer/inertia navigation type tester is not utilized, the brakes shall be road tested on a level, dry, smooth, hard surface that is free of loose material, oil, or grease to determine whether the motor vehicle is able to stop from a speed of 20 miles per hour in 30 feet or less without swerving out of a 12-foot wide lane. If the private inspection facility performs a road test of the brakes, a diagram of the test location shall be provided to the Private Inspection Facility Licensing Unit of the Motor Vehicle Commission at the address specified in N.J.A.C. 13:20-44.4(a).

(n) If a motor vehicle is equipped with air brakes, the low pressure warning system and air brake components shall be tested for proper operation. This test includes the following:

1. The low pressure warning system. The engine shall be turned off when there is sufficient air pressure so that the low pressure warning signal is not illuminated. The electrical power shall be turned on and the brake pedal shall be depressed and released to reduce the air tank pressure. The low air pressure warning signal shall become illuminated before the air pressure drops to less than 60 pounds per square inch in the air tank (or, in dual air systems, in the tank with the lower air pressure).

2. Operation of automatic spring brakes. The motor vehicle wheels shall be chocked, the parking brake released when there is sufficient air pressure to do so, and the engine turned off. The brake pedal shall be depressed and released to reduce the air tank pressure. The parking brake knob shall pop out when the air pressure falls to the manufacturer's specification, which is usually in a range of between 20 to 40 pounds per square inch. This shall cause the spring brakes to engage.

3. Rate of air pressure increase. With the motor vehicle engine idling at the motor vehicle manufacturer's specification, the air pressure shall increase from 85 pounds per square inch to 100 pounds per square inch within 45 seconds in dual air systems. If the motor vehicle is equipped with larger than minimum air tanks, the rate of increase may be longer as per the manufacturer's specifications. In single air systems on pre-1975 model year motor vehicles, typical specifications are an air pressure rate of increase from 50 to 90 pounds per square inch within three minutes with the engine at an idle speed of 600 to 900 revolutions per minute.

4. Air leakage rate. With a fully-charged air system (typically 125 pounds per square inch), the engine shall be turned off, the service brake shall be released, and the air pressure drop shall be timed. The loss rate shall be less than two pounds per square inch in one minute for single vehicles, or less than three pounds per square inch in one minute for combination vehicles. Ninety pounds per square inch or more shall then be applied to the brake pedal. After the initial pressure drop, the air pressure shall not fall more than three pounds per square inch in one minute for single vehicles, nor more than four pounds per square inch in one minute for combination vehicles.

5. Governor cut-in and cut-out pressure. The air compressor shall start pumping at approximately 100 pounds per square inch and shall stop pumping at approximately 125 pounds per square inch as per the manufacturer's specifications. The motor vehicle engine shall be operated at a fast idle. The air governor shall cut-out the air compressor at approximately the manufacturer's specified pressure. The air pressure indicated on the air pressure gauge(s) shall stop rising. With the engine idling, the brake pedal shall be depressed and released to reduce the air tank pressure. The air compressor shall cut-in at approximately the manufacturer's specified cut-in pressure, and the air pressure shall begin to rise.

N.J. Admin. Code § 13:20-33.47

Amended by 48 N.J.R. 810(a), effective 5/16/2016