Generac Power Systems 53187 - Manual (Page 90)

SECTION 3.2
WATER PUMP & THERMOSTAT
1
Water Pump (Continued)
REASSEMBLY (CONT’D):
4. Install a mechanical seal into the impeller by hand.
Apply 4 or 5 drops of silicon oil to the contact surface
of the mechanical seal.
5. Press the impeller into the casing until the impeller
end is
O.70 inch (17.8mm) from the end of the bearing.
See Figure 5.
Figure 5. Press Im peller Into Casing
6. Use a SETSCREW to retain the bearing (Figure 6).
Then, press the fan pulley into place until the bearing
shaft end is aligned with the end face of the fan holder.
PART 3- LUBRICATION
AND COOLING SYSTEM
7. Assemble the thermostat and spring to the water
pump casing. Install gaskets, plate and cover. Retain
with bolts.
Figure 7. Therm ostat Assem bly
8. Rotate the fan pulley to ensure there is no interfer­
ence.
9. Adjust fan belt tension to obtain a 0.20 inch (5mm)
belt deflection when a 2.2 pound (1 kg) force is applied
to center of belt.
10. Test run the engine until hot toconfirm there are no
water leaks.
Thermostat
To test thermostat operation, immerse it in water. Raise
the
water temperature gradually. Check the valve
opening temperatures and the valve lift.
NOTE: About 3 to 5 m inutes will be required before
the valve starts to operate.
Starts to Open:
Fully Open at:
Valve Lift at
Fully Open: 158’ F. (70‘ C.)
185* C. (85’ C.)
0.31 inch (8.0mm)
Figure 6. Fan Pulley & Setscrew Installation Figure 8. Testing the Therm ostat
PAGE 3.2-2