VALVES AND VALVE SEAT REFACING

TM 10-3930-638-24&P

4-2. ENGINE MAINTENANCE (cont)

b. Cylinder Head and Valves (cont).

REMARKS

ITEM

ACTION

LOCATION

STEP

VALVES AND VALVE SEAT REFACING

At 44 degree angle

Set

a. Protractor

Refacing

Clean

b. Chuck

machine

Dress

c. Grinding wheel

Grinding angle is 44 degrees

Grind lightly

Valves (6 and 7)

NOTE

Replace any valve that has a thin margin or edge. If margin on

ground valve is less than half margin on new valve, replace that

valve.

Grinding angle as shown. Use precision seat

Grind lightly

Valve seats

grinder. Take very light cuts to remove

and inserts (14)

just enough metal to obtain a smooth seat

finish.

Use Prussian Blue. Apply to valve face

a. Apply valve

Valves (6 and 7)

bluing

In cylinder head (8). Rotate valve in seat

b. Install

Check contact area on valve face and seat.

c. Remove

Bluing will be removed from valve face

where contact was made with seat. Cor-

rect and incorrect indications along with

remedial procedures are shown below

4-16