6.4
Section 6
Lubrication System
Testing
The Oil Sentry™ pressure monitor is a normally
closed type switch. It is calibrated to open (break
contact) with increasing pressure and close (make
contact) with decreasing pressure within the range of
3.0/5.0 psi
.
Compressed air, a pressure regulator, pressure gauge,
and a continuity tester are required to test the switch.
1. Connect the continuity tester across the blade
terminal and the metal case of switch. With 0 psi
pressure applied to the switch, the tester should
indicate continuity (switch closed).
2. Gradually increase the pressure to the switch.
The tester should indicate a change to no
continuity (switch open) as the pressure
increases through the range of 3.0/5.0 psi.
The switch should remain open as the pressure is
increased to 90 psi maximum.
3. Gradually
decrease
the pressure to the switch.
The tester should indicate a change to continuity
(switch closed) as the pressure decreases through
the range of 3.0/5.0 psi; approaching 0 psi.
If the switch does not operate as specified,
replace the switch.
Reduction Gear Units
On engines with a reduction gear unit, remove the oil
plug on the lower part of cover every
50 hours
of
operation to check oil level. With the engine level, the
oil level of the unit should be up to the bottom of the
oil plug hole. To add oil, remove the vented plug at the
top of the unit. Use AGMA No. 7 EP oil in the
reduction gear unit. Following are a few products
that meet this spec:
Mobilgear 634
Pennzoil Super Maxol "S"
Pennzoil Maxol EP Gear Oil
Pennzoil Super Maxol EP Gear Oil
Pennzoil Super Pennztac EP Gear Oil
Figure 6-9. New Relief Valve.
Oil Sentry™ Oil Pressure Monitor
Some engines are equipped with an optional Oil
Sentry™ oil pressure monitor. See Figure 6-5. Oil
Sentry™ will either stop the engine or activate a “low
oil” warning light, if the oil pressure gets low. Actual
Oil Sentry™ use will depend on the engine
application.
Operation
On stationary or unattended applications (pumps,
generators, etc.), the pressure switch can be used to
ground the ignition module to stop the engine.
On vehicular applications (lawn tractors, mowers,
etc.), the pressure switch can be used to activate a low
oil warning light.
NOTE:
Oil Sentry™ is not a substitute for checking
the oil level BEFORE EACH USE. Make sure
the oil level is maintained up to the “F” mark
on the dipstick.
Installation
The pressure switch is installed in the oil filter
adapter, in one of the main oil galleries of the closure
plate see Figure 6-5. On engines not equipped with Oil
Sentry™, the installation hole is sealed with a 1/8-27
N.P.T.F. pipe plug.
1. Apply
Loctite
®
No. 592 pipe sealant with Teflon
®
(or equivalent) to the threads of the switch.
2. Install the switch into the tapped hole in oil filter
adapter.
3. Torque the switch to
6.8 N·m (60 in. lb.)
.
