VALVE GP-BRAKE 3663832 - Caterpillar

Be sure the engine cannot be started while this maintenance is being performed. To prevent possible injury, do not use the starting motor to turn the flywheel.Hot engine components can cause burns. Allow additional time for the engine to cool before measuring/adjusting engine valve lash clearance.
Adjusting the valve lash several times in a short period indicates wear in a different part of the engine. Find the problem and make any necessary repairs in order to prevent more damage to the engine.Rapid wear of the camshaft and tappets can occur if insufficient valve lash is not corrected. Insufficient valve lash can also be an indication of faulty valve seats. The following items are reasons for faulty seats of the valves: faulty fuel injection nozzles, restrictions to the air inlet, dirty air filters, incorrect fuel setting and overloading the engine.Broken valve stems, broken pushrods, or broken spring retainers can be caused by insufficient valve lash that is not corrected. A fast increase in valve lash can be an indication of any of the following items:
Worn camshaft and tappets
Worn rocker arms
Bent pushrods
Loose adjustment screws for valve lash
Broken socket on the upper end of pushrodFuel in the lubrication oil may be a possible cause of rapid wear of the camshaft and the tappets. Dirty lubrication oil may also be a possible cause of rapid wear of the camshaft and tappets.Valve Lash Setting with Stopped Engine (Cold) Inlet and Exhaust Valve ... 0.25 mm (0.010 inch)
Remove the valve covers.
Turn the crankshaft until the No. 1 piston is at the top center on the compression stroke. Refer to, "Finding Top Center Position for No. 1 Pistion" for the correct procedure.
Illustration 1 g00526261
Valve Lash
Adjust the valve lash on the inlet valves for cylinders 1, 2, and 4. Adjust the valve lash on the exhaust valves for cylinders 1, 3, and 5.
Turn the flywheel for 360 degrees in the direction of engine rotation. The No. 6 piston will be at the top center (TC) on the compression stroke.
Adjust the valve lash on the inlet valves for cylinders 3, 5, and 6. Adjust the valve lash on the exhaust valves for cylinders 2, 4, and 6.
Hold the adjustment screw and tighten the locknut after the adjustment is complete.