New Holland CX720 Repair Manual page 1686

4. Use a seat cutter to correct any seat eccentricity, or
clean up of pits and grooves. Ensure after any re-
work that seat width is within specified limits.
Rotate a new or refaced valve in the seat using engi-
neering blue, ensure all the blue is transferred to the
valve head protrusion, If any blue remains below or
around the seat raise or lower the seat accordingly,
Fig. 3, in the following manner.
Lower, the valve seats (1) Fig. 3, by removing mate-
rial from the top of seat using a, 30 ° grinding wheel
for exhaust valves and a 15 ° grinding wheel for in-
take valves.
Raise, the valve seats (2) Fig. 3, by removing ma-
terial from the bottom of seat using a, 60 ° grinding
wheel for exhaust valves and a 45 ° grinding wheel
for intake valves.
5. Critical valve points, Fig. 4:
1. Valve Land Edge
2. Valve Head
3. Valve Face Angle
4. Valve Face
5. Valve Stem
6. Valve Tip
6. Valve Guides
Using a telescopic gauge, and micrometer, measure
the valve guide bore clearance, and ensure it does
not exceed,
0.114 mm (0.0045 in), on the intake valve stem,
0.140 mm (0.0055 in),
on the exhaust valve stem, Fig. 5.
NOTE: Production cylinder heads may have one or more
machined, oversize valve guide bores, or valves installed,
0.015 in (0.38 mm). Such cylinder heads have 15 or
VO15OS stamped on the cylinder head exhaust manifold
side adjacent to the valve concerned.
7. Using reamer set, 295006 (NA-FNH02136), ream
out the valve stem guide, with three reamer and pilot
combinations as follows:-
When going from a standard valve stem to an over-
size, always use reamers in sequence
38 mm (0.015 in) oversize reamer, and 0.076 mm
(0.003 in) oversize pilot.
POWER PRODUCTION - ENGINE
2 4/7/2006
B.10.A / 140
3
TA6010016
4
TA6010017
5
TA6010018