
Fig. 47Trim the Cylinder Opening Side with Reamer
Fig. 49 Detach the Piston Ring
Fig. 48 Check How the Piston Matches the Piston Pin
Fig. 50 Remove the connecting rod off the piston
(1) .Standard diameter, standard type of dimension groups refers
to table 4:
(2) .Maximal diameter, standard type: 78.93mm
(3) .Extra dimension 0.50 (type): 79.43mm
If the diameter is bigger than the maximal value, all the 4 cylinders
shall be re-bored. Replace the cylinder block if necessary.
5. Trim the bulge of cylinder upper part
Remove the bulge generated by abrasion and the combustion
residue around the cylinder opening. If the abrasion is smaller than
0.2mm, refine the cylinder opening side with a reamer (Fig. 47).
6. Check how the piston matches the piston pin, and try to move
the piston forward and backward. If the move occurs, replace the
whole set of piston and piston pin (Fig. 48).
7. Detach the piston ring (Fig. 49)
(1) Remove the 2 compression rings with the piston ring expander.
(2) Remove the oil ring and the liner ring by hand. The piston ring
must be located in proper sequence.
8. Remove the connecting rod off the piston, press the piston pin
out of the piston with the dedicated servicing tools, and take out the
connecting rod (Fig. 50). Do not deform the piston by pressing it.
Make sure the piston and the pin come from the same original kit.
Locate the piston, piston pin, the ring, the connecting rod and the
bearing shell in proper sequence.
9. Clean the piston, clear the carbon deposit with scraper, and
wash the piston completely with solvent and brush.
10. Check the clearance to decide the cylinder servicing dimen-
sions.
(1) Check the oil film clearance of piston
There’re 3 dimension groups, named as group “1”, “2” and “3” of standard piston diameter.
37
Содержание JL481Q
Страница 1: ......
Страница 9: ...5 Fig 3 Components Assembly Drawing of MR479Q MR479QA Engine ...
Страница 10: ...6 Fig 4 MR479Q MR479QA Engine and Its Power System ...
Страница 11: ...7 Fig 5 Assembly Drawing of Engine and Its Auxiliaries MR479Q MR479QA ...
Страница 12: ...8 Fig 6 Electronic Control Fuel Injection System in Engine MR479Q MR479QA ...
Страница 13: ...9 Fig 7 Front view of Engine JL481Q MR481QA ...
Страница 14: ...10 Fig 8 Sectional elevation of Engine JL481Q MR481QA ...
Страница 15: ...11 Fig 9 Electronic Control Fuel Injection System in Engine JL481Q MR481QA ...
Страница 21: ...17 Fig 13 Exterior Feature of JL481Q Engine Power Me N m Torque Pe Kw ge g kwh Fuel Consumption Ratio ...