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WT5C SERIES WATER TRAILER • OPERATION MANUAL — REV. #6 (05/28/21) — PAGE 27
MAINTENANCE
PUMP VACUUM TEST
To perform the pump vacuum test do the following:
1. Remove the pump fill cap and fill the pump with water.
2. Start the engine as outlined in the operation section,
and wait for the pump to begin pumping.
3. As shown in Figure 27, place a water hose inside
the discharge opening of the pump, and turn on the
water. This flow of water into the discharge opening
will prevent the pump from running dry.
4. Place the Pump Vacuum Tester (P/N 7000030) over the
pump suction (inlet) opening with the vacuum gauge
facing upwards. It may be necessary to apply a small
amount of water around the rubber seal of the vacuum
tester to make a good suction fit.
5. Check and make sure that there are no air leaks
between the vacuum tester and the inlet port on the
pump. If air leaks are present reset vacuum tester.
6. Run the pump for a few minutes while monitoring
the vacuum gauge. If the gauge indicates a reading
between -25 and -20 in. Hg. (inches of mercury) then
it can be assumed that the pump is working correctly.
7. If the vacuum tester gauge indicates a reading below
-20 in. Hg, it can then be assumed that the pump is
not functioning correctly, and corrective action needs
to be taken.
CAUTION
DO NOT
attempt to start the engine unless the pump
has previously been primed with water. Severe pump
damage will occur if pump has not been primed.
NOTICE
25 in. Hg (inches of mercury) translates into 25 feet of
lift at sea level.
Figure 27. Pump Vacuum Test
NOTICE
Vacuum test may be performed without water flowing
through the discharge port. However, it is recommended
to have water flowing to prevent any heat-up.