Drive Train - Tayana 37 Operation & Maintenance Manual

* Hint: Very often the Yanmar 3QM30 engine can be bled simply by loosening the
bleed screw on top of the engine oil filter and the bleed screw on top of
the injection pump. Try it.

2. Drive Train

(d) Follow the fuel line from the pump to the engine fuel filter
and locate the vent plug on top. Loosen plug two or three
turns.
(e) It is advisable to have some large rags on hand to catch oil
that will be expelled from this point in the course of
bleeding.
(f) Begin operating the manual lever. This may take several
minutes as the filters will need to fill up (as well as the
lines). Operate the manual lever until fuel flows freely from
the filter plug with no signs of air bubbles.
(g) Loosen the bleed screws on the injection pump.
(h) Operate pump again until fuel flows freely with no air
bubbles.
(i) Re-tighten the vents beginning with the lowest point (the
filter, the head locking screw, and the governor vent
screw).
(j) Wipe up any spills at this time.
(k) Slacken the union nut at the injection-nozzles.
(l) Move throttle to full rpm and check to see if the "stop"
control is in "run" position.
(m) Crank engine with starter motor until fuel flows from each
injector.
NOTE: Do not run starter motor
continuously. It normally takes 30
to 60 seconds of cranking to completely
bleed the injector lines.
20 seconds of cranking with about
a two-minute rest between periods
will be easier on the starter,
motor, and battery than steady cranking.
(n) Re-tighten injector lines, wipe spills .
(o) Re-set throttle position and proceed with normal start-up.
(p) Allow sufficient running time to recharge battery.
V-16