Shibaura ST330, Workshop Manual

Page: 209 / 250

198
16) ENGINE OIL PRESSURE
SWITCH
Description and Lo catio n
The engine oil pressure switch , 1, is located
in the front of the eng ine cy linder head.
The o il p ressure switch is located on top of
the cy linder h ead. The engine oil p ressure
switch closes (circuit co mp leted) when
engine oil pressure is less than 29 .4 kPa.
This illuminates an indicator light on th e
instru men t pan el lights.
The engin e oil pressure switch is closed
before th e tracto r engin e is started , and is
open ed after the engine is started. If th e
indicator light fails to switch after th e
tractor is started , the oil level inside th e
engine may be low or there may be a problem
with th e o il pump or relief v alv e assembly.
Engine Oil Pressure Sw itch Testing
1. U sing an ohmmeter, touch on e test lead to
th e pressure switch termin al, 1, and th e
other test lead to the th reads o f th e switch
body, 2 .
2. Observ e the oh mmeter. Th ere should b e
little or no resistance, ind icating
continuity in the switch.
If th ere is no con tinuity, th e switch is
defectiv e an d needs rep laced.
CAUTION:
Do not use hig h pressure co mpressed air for
the following test, otherwise damag e may
occur to the oil pressure switch.
NOTE :
The follo wing test is no t a calibrated test.
The purpose of th e test is to see if th e switch
conta cts open at pressu re.
3. While the test leads are connected to th e
switch , pressurize th e switch oil p ressure
port, 3, w ith low pressure 69
～ 138 kPa
{0.7 ～ 1.4 kgf/c ㎡ } compressed air.
4. Observ e the ohmmeter. W hile air p ressure
is b eing supplied to th e oil pressure port,
th e oh mmeter should indicate high
resistan ce, or no continuity. If th ere is
continuity, the switch is d efectiv e and
needs rep laced.
Insta llatio n
1. Install th e oil pressure switch into th e
engine cy linder head and tighten to 14 .7 ～
19.6 N
･
m (1.5
～
2 .0 kgf
･
m).
2. Install t he ring terminal onto th e o il
pressure switch, and secure the terminal
with th e retaining screw, 1.
550Y
551Y
NOTE : If the oil pressure switch is too
mutch tightened , will b e broken the
support ba cket
.