Page 70 - Mechanic Diesel - TT

MECHANIC DIESEL - CITS

• Bucket-type OHC heads
• Lubricate buckets and install them in the head prior to installing the cam
• Adjust the valve clearance before installing the head on the engine
• Valve lash must be enough to allow heat to dissipate from valve to valve seat

Safety with Cylinder Heads and Valves
Keep these 10 safety precautions in mind when working with cylinder heads, valves, valve springs, camshafts,
and rocker arms.
1 Always wear safety glasses around the shop. Wear the glasses at all times while in the shop, even while

looking up specifications, reviewing procedures, or working on cylinder head components. Get in the habit of
keeping the safety glasses on at all times.
2 The edges of the cylinder head may be very sharp because of the machined surfaces. Be careful not to cut
your fingers when handling the cylinder head.
3 During cleaning, pieces of carbon and soot are usually removed from the valves and cylinder heads. Be
careful not to breathe in the carbon dust.

4 When valves and valve springs are being removed or installed, the valve springs are depressed and under
high pressure. Make sure the valve spring compressor is secured correctly on the valve so the spring will not
slip under pressure. Your eyes and face may be injured if you are hit by a spring that has slipped out of the
grasp of the tool.

5 Make sure that any electrical tools used for cleaning valves or cylinder heads are grounded correctly.
Never use an electrical tool while standing in wet are as in the shop
Back to Safety
6 Often the top edges of used lifters are very sharp. This is caused by the cam lobe wearing on the top of the
lifter. Be careful not to cut your fingers on these sharp edges when removing lifters.
7 When installing a camshaft, be careful not to pinch your fingers between the cam bearings and the cylinder
block holes.

8 Make sure that all tools used for working on the camshaft and valves drive mechanisms are clean and free of
dirt and grease.
9 When grinding valves or using other electrical equipment, never string an extension cord across the floor.
10 Many of the bolts and nuts require high torque specifications. Always use the correct Torque wrench, and
know the torque specifications when working with cylinder heads.

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CITS : Automotive - Mechanic Diesel - Lesson 11 - 14 CITS : Automotive - Mechanic Diesel - Lesson 11 - 14