New Jersey Administrative Code › Title 13 - LAW AND PUBLIC SAFETY › Chapter 20 - ENFORCEMENT SERVICE › Subchapter 32 - INSPECTION STANDARDS AND TEST PROCEDURES TO BE USED BY OFFICIAL INSPECTION FACILITIES › Section 13:20-32.47 - Service brakes (including service brake equalization and service brake pedal reserve) requirements, all vehicles; commercial vehicle inspection at official inspection facilities

Current through Register Vol. 56, No. 14, July 15, 2024
(a) The inspection for commercial 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 commercial 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 vehicle engine shall be running when power brakes are tested. In the event that the adequacy of the service brake pedal reserve on a 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 commercial vehicle is so equipped, no illumination of the brake system failure indicator light. If a 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) 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.
(g) The vacuum brake hoses shall be examined visually and aurally with the commercial motor vehicle engine running. The hoses shall not be collapsed, abraded, broken, improperly mounted, or audibly leaking.
(h) After ensuring that the tires are properly inflated, a brake performance test shall be conducted as part of the inspection. The brakes shall be tested on a drive-on platform tester or any other brake performance tester approved by the Chief Administrator. 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.
(i) If a commercial 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 commercial 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 commercial 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; and
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.