Isuzu N-Series. Manual - part 318
6A-14 ENGINE MECHANICAL
2. Use a bench press (3) to gradually apply pressure
to the attachment and press the valve seat insert
into place.
Caution:
Do not apply an excessive amount of pressure with the
bench press. Damage to the valve seat insert will result.
3. The valve should be lapped before final assembly
to ensure a good valve seal.
Above works refer to “Valve Seat Insert Correction”
section in this manual.
Valve Seat Insert Correction
1. Remove the carbon from the valve seat insert sur-
face.
2. Use a valve cutter (15
°, 45°, and 75° blades) to
minimize scratches and other rough areas. This
will bring the contact width back to the standard
value. Remove only the scratches and rough ar-
eas. Do not cut away too much. Take care not to
cut away unblemished areas of the valve seat sur-
face.
Notice:
Use an adjustable valve cutter pilot.
Do not allow the valve cutter pilot to wobble inside the
valve guide.
3. Apply abrasive compound to the valve seat insert
surface.
4. Insert the valve into the valve guide.
5. Turn the valve while tapping it to fit the valve seat
insert.
6. Check to see if the valve contact width is correct.
7. Check to see if the valve seat insert surface is in
contact with the entire circumference of the valve.
Reassembly
1. Spring Lower Seat
N6A0134E
N6A0135E
Valve Seat Angle
Degrees
45
°
N6A0136E
N6A0137E