JUKI MF-7900 Series Engineer's Manual page 65

Adjustment procedures
1. Inspection and replacement
Loosen setscrews ❸ in the oil filter cap and remove oil filter
cap ❷ .
Draw out oil filter ❶ to inspect it. When it is clogged with dust,
replace it with a new one.
After the replacement, fix oil filter cap ❷ with setscrews ❸ in
the oil filter cap.
(Caution) When removing the oil filter cap ❷ , lubricating oil
collected in oil filter ❶ will leak out. So, be careful.
2. Oil circulation identification
(1) In case the oil does not come out from oil circulation identifi-
cation window ❹ even when oil filter ❶ is replaced with a new
one, remove four setscrews ❻ in the oil pan ❺ , remove oil
pan ❺ , and tilt the machine head to the rear up to the position
where pipe connecting joint screw  can be removed.
(2) Oil sucked up from gear pump ❼ passes oil pipe ❽ and enters
oil filter ❶ from pipe connecting joint screw ❾ . When the lubri-
cation oil does not rise to oil circulation identification window ❹ ,
The hole in pipe connecting joint screw ❾ may be clogged with
dust. So, check it.
(Caution) When there is any foreign material in oil pan ❺ , re-
move it.
Results of Improper adjustment
◦ In case oil cannot be observed
from oil circulation identifica-
tion window ❹ even when the
sewing speed is 2,500 sti/min or
over, the machine will be in dan-
ger of seizure if the operation is
continued.
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