ROCKER ARM AS 3855474 - Caterpillar

3406B (7FB, 8TC, 4MG, 5YG, 3ZJ, 5KJ, 2EK) Truck EnginesStepped up enforcement of two laws aimed at improving air quality in the State of California may soon result in citations issued to owners of vehicles emitting excessive black smoke while operating within state boundaries. All heavy-duty diesel powered trucks, regardless of their state registration, will be subject to these enforcement practices.
California Air Resources Board (CARB) Snap Idle Test
In 1988, California enacted Senate Bill SB 1997 creating Section 44011.6 in the California Health and Safety Code. This section authorizes CARB, in conjunction with the California Highway Patrol (CHP), to issue citations to owners or operators of vehicles that emit excessive smoke or have emission control system components that have been tampered with or are malfunctioning.
Owners of cited vehicles are required to have them repaired immediately and to pay a civil penalty of $800 for the first violation. If repair is made within 45 days, $500 will be refunded. The penalty for second and subsequent violations within 12 months is $1800. There is no refund for the second or subsequent violation, and subsequent violators must submit to a mandatory post-repair test. CARB has authority to fine up to $1500 per day for each day the vehicle is in violation, and subsequent violators with outstanding unpaid citations may be subject to vehicle impoundment.
The method used to determine compliance with Health and Safety Code Section 44011.6 is a no-load "snap idle" test with exhaust smoke measured in percent opacity using a light extinction type smoke meter. The smoke meter most commonly used is a Wager Model 650A.
The CARB Snap Idle test is simple to perform. With the vehicle stationary, and the engine at normal operating temperature at low idle, the engine is accelerated rapidly to high idle speed three times to "clear out the stacks". Then, with the smoke meter in place, the procedure is repeated. The average of the two closest peak opacity readings is the smoke number used for comparison to the smoke standard.
Before the test is performed, it is very important to make sure the Fuel Ratio Control (FRC) is "cocked" or activated. Most FRC's require both oil pressure and boost to cock. If the snap idle test is performed in the field by a CARB inspection team, the engine should be kept running to avoid deactivating the FRC. If the engine is shut down, operate the engine to develop 5-10 psi boost before a smoke test is performed.
The current smoke standard is 55% for pre-1991 model year heavy-duty diesel vehicles, and 40% for 1991 and newer vehicles. The proposed standard is 40% for all 1974 and newer model year heavy-duty diesel vehicles unless an exemption is obtained. Vehicles exempt from the 40% standard, must still meet the 55% standard.
Air Quality Management Districts (AQMD) Lug Test
The AQMD have initiated a separate program authorized under California Vehicle Code, 42001.2 to regulate smoke emissions. While centralized in the South Coast Air Basin region, program enforcement can be conducted by state and