155425-1420 ZEXEL 9 421 616 458 BOSCH ANEROID CAPSULE 9421616458 1554251420 1157281110

The purpose of the air induction system is to provide clean air to the engine in an efficient, unrestricted, silent manner while the exhaust system discharges exhaust gases as quickly and as silently as possible with minimum backpressure. Engine horsepower and efficiently will be reduced if either the air inlet or exhaust becomes restricted. Good maintenance practice cannot be over emphasized. AIR CLEANERS: Regular service intervals, along with close visual inspection of the air cleaner, are necessary for proper cleaning of the engine inlet air. The service interval will vary with the weather and working conditions. Where dust conditions are severe, it will be necessary to service the air cleaner frequently. In damp weather and other conditions of little or no dust, the service interval can be extended.To extend the service life of the element, the exhaust and air cleaner inlet pipes should be arranged so that exhaust and/or oil fumes do not enter the engine air cleaner.Visual inspection of the gaskets and seals is important in keeping dust from by-passing the air cleaner. Any dirt allowed to enter, accelerates wear throughout the engine. If the condition of any of the replaceable seals and gaskets is questionable, replace them. If the sealing ends of the filter element or the element pleats are damaged. replace the element.Extra filter elements should be kept on hand for replacement or for use in the air cleaner while the element that was removed is being cleaned.When equipped with a dry-type air cleaner, a service indicator similar to the one shown is available. The air cleaner service indicator is connected to the air inlet pipe between the air cleaner and the manifold. It contains a red marked piston, which gradually rises with restriction to the air flow. When the entire piston is visible it will lock in this position. This indicates a need for air cleaner service. The piston will remain in this position whether or not the engine is running. After servicing the air cleaner, reset the piston by depressing the plunger in the bottom of the indicator.Excessive engine exhaust smoke and/or loss of power may indicate the need for servicing the air cleaner. Never service the air cleaner while the engine is running.(See your truck manufacturer's operator's books for maintenance intervals and instructions.) Air cleaner restriction at high idle should not exceed 25 inches (635 mm) of water.Valve Lash
Make valve lash adjustment with engine stopped.Top dead center (TDC) of the No. 1 piston on the compression stroke is the reference point. The No. 1 piston is at TDC compression stroke when the timing mark on the crankshaft damper or the pulley is aligned with the timing pointer, and No. 1 and No. 2 exhaust and inlet valves are closed. (The rocker arms are free.) To Adjust The Valve Lash
1. Adjust lash for No. 1 and No. 2 exhaust and inlet valves. a. Loosen valve adjusting screw locknut.b. Turn adjusting screw to allow a clearance gauge to pass between the top of