Usage:
Valve Lash
Preparing To Check Adjustment
- 1. Stop the engine. Allow it to cool at least 20 minutes.
- 2. Remove the flywheel housing timing cover(s).
REMOVING TIMING COVER(S)
- 3. Wipe dirt from the base of the valve covers.
- 4. Remove the valve covers.
- 5. Move the compression release lever to the START position.
COMPRESSION RELEASE LEVER
- 6. Bar the flywheel counterclockwise. Align the "TDC 1-6" timing mark with the timing pointer on the flywheel housing.
Numbering Of Cylinders
Checking Adjustment:
- 1. Observe the rocker arms for cylinder No. 1. Determine if the piston is on compression or exhaust stroke.
Compression stroke: Both intake and exhaust valves are closed.
Exhaust stroke: Intake valve is closed, exhaust valve is opened.
- 2. With NO 1 CYLINDER ON COMPRESSION STROKE, check the lash of the following valves: Adjust if necessary.
- 3. Bar the flywheel counterclockwise one revolution. Align the "TDC 1-6" timing mark with the timing pointer on the flywheel housing.
- 4. With NO. 1 CYLINDER ON EXHAUST STROKE, check the lash of the following valves; adjust if necessary.
Adjusting Valve Lash
- 1. Loosen the locknut on the adjusting screw.
LOOSENING LOCKNUT
- 2. Hold the locknut and turn the adjusting screw to obtain the proper lash.
ADJUSTING VALVE LASH
- 3. Hold the adjusting screw and tighten the locknut.
- 4. Recheck the lash.
Valve Rotators
Checking Rotation
After checking all valve clearances, and before installing the valve covers:
- 1. Start the engine.
- 2. Move the governor control to low idle position.
- 3. Watch the serrations on each valve retainer. Each valve retainer should turn slightly each time the valve closes.
If it is suspected a valve is not rotating, contact your Caterpillar dealer. Repairs must be made to prevent burning the valve.
If all valves rotate, proceed as follows:
- 4. Stop the engine.
- 5. Inspect and install valve cover gaskets. Install new gaskets if necessary.
- 6. Install the valve covers.
- 7. Install the flywheel housing timing cover.
Exhaust Bypass Valve Breathers
Remove both exhaust bypass valve breathers and wash them in clean kerosene.
CHECK VALVES FOR ROTATION
REMOVING BREATHER ELEMENT