PUMP 2990920 - Caterpillar

To prevent possible injury, do not use the starter to turn the flywheel. Hot engine components can cause burns. Allow additional time for the engine to cool before measuring valve clearance.
This engine uses high voltage to control the fuel injectors.Disconnect electronic fuel injector enable circuit connector to prevent personal injury.Do not come in contact with the fuel injector terminals while the engine is running.
The engine valve lash must be within specifications prior to adjusting the lash for the compression brake. Refer to Testing and Adjusting, "Engine Valve Lash - Inspect/Adjust" for the correct procedure for inspection of the engine valve lash.Note: Adjustment of the lash for the compression brake must be performed while the engine is cold. If the engine is warm, allow the engine to cool prior to performing the following adjustments.
Illustration 1 g01525810
(1) Locknut
(2) Adjustment screw
Illustration 2 g01525809
(3) Brake piston
(4) Valve bridge Use the following procedure to adjust the compression brake on cylinders one, three and five.
Position the number one piston to the top center position of compression stroke. Refer to Testing and Adjusting, "Finding Top Center Position for No. 1 Piston".
Turn adjustment screw (2) clockwise until the brake piston (3) touches valve bridge (4).
Turn adjustment screw (2) counterclockwise until the nut has turned one full rotation.
Use a feeler gauge to ensure that the brake lash is set at 0.9 0.2 mm (0.035 0.008 inch).
Tighten the locknut (1) to a torque of 50 10 N m (37 7 lb ft). Do not allow the adjustment screw to turn while you are tightening the adjustment locknut. Recheck the valve lash after tightening the adjustment locknut. Use the following procedure to adjust the lash on cylinders two, four, and six.
Position the number six piston to the top center position of compression stroke.
Turn adjustment screw (2) clockwise until the brake piston (3) touches valve bridge (4).
Use a feeler gauge in order to verify the brake lash of 0.9 0.2 mm (0.035 0.008 inch). The brake lash is measured between brake piston (3) and valve bridge (4).
Tighten locknuts (1) to a torque of 50 10 N m (37 7 lb ft). Do not allow adjustment screw (2) to turn while you are tightening locknut (1). Recheck the valve lash after tightening the locknut.