WinGD RT-flex50DF, Maintenance Manual, Page: 325 / 586

Maintenance
3403 − 4/A1
Winterthur Gas & Diesel Ltd.
1/ 2
Top Surface Check
Tools:
1 Feeler gauge 94122
1 Template 94366A
1 Template 94366B
1. General
Each time you remove a piston, you must do a check of the top surface of the piston
head for damage (burn scars).
The causes of burn scars are as follows:
D Poor combustion
D Worn nozzles
D Heavy local carbon particles on top of the piston head etc.
Note: You can also do this check with the piston installed.
2. Procedure − Piston
Removed
1) Put the template (94366B, Fig. 1 ) in
position on the top piston ring.
2) Turn the template (94366B) around the
axis of the piston head.
3) Use the feeler gauge (94122) to
measure the depth of the burn scar(s).
4) Remove the template (94366B).
Note: You can also use a depth gauge to
measure the depth of the burn
scar(s).
5) If the burn scars are less than 10 mm,
do step a ) and step b ):
a) Use an applicable tool to grind the
burn scars.
b) Use emery paper to make sharp
edges smooth.
6) If the burn scars are more than 10 mm,
do step a ) to step c ):
a) Remove the piston head, refer to
3403 − 3, paragraph 1 and
paragraph 2 .
b) Do the procedure to surface weld
and repair the piston head to its
original thickness.
c) Assemble the piston (refer to
3403 − 3, paragraph 3 ).
Note: Before you start the engine, find
the cause of the burn scars.
Piston
2016
94366B
018.587/09
10 mm
Fig. 1
Piston
Ring