Table 4-2. Unit Troubleshooting Guide (Continued)
TEST OR INSPECTION
High pressure pump motor runs but pump doesnt build up any pressure.
Step 1. Check the belts for wear.
Replace, if worn (para. 4-81).
Step 2. Check drive belt tension.
Adjust to correct tension (para. 4-81).
High pressure pump has excess water flowing out of the bottom of the pump.
Notify direct support maintenance.
High pressure pump oil looks milky (has water in it).
Step 1. Change oil, refer to para. 4-81.
Step 2. Check pump plunger cavity.
Clean out drain hole.
Notify direct support maintenance to change pony rod oil seals and to check plunger packing for wear
and excessive leaking.
8.1. High pressure pump does not respond to jog switch.
Refer to MALFUNCTION 9.
High pressure pump motor hums and wont turn.
Failure to turn off the high pressure pump circuit breaker before proceeding could result in injury or death.
Step 1. Check motor ease of rotation. Loosen drive belt and turn motor by hand (para. 4-81).
If the motor cant be turned easily by hand, notify direct support maintenance.
Step 2. Check pump ease of rotation. Loosen drive belt and turn pump by hand (para. 4-81). The pump will take
more effort to turn than the motor but it will not require a great deal of effort.
If the pump turns fairly easily, notify direct support maintenance.
Step 3. Check for pump freezing.
If the pump has not been exposed to freezing conditions and wont turn over, notify direct support
maintenance to replace/repair the pump.
Open the seven drain valves on the pump and the high pressure drain valves on the RO elements
Start the raw water pump and make sure the skid heater is on.
If an extra heater is available use it to put more heat on the pump.
Continue until water flows freely from all valves and the pump turns over.
If the pump still wont turn over, notify direct support maintenance to replace/repair the pump
High pressure pump runs, pretreatment gages read high, but there is no waste flow.
Check for a plugged line between the cartridge filter and the high pressure pump (para. 4-45).
High pressure pump starts but shuts down on product high pressure. System "normal" operation
Step 1. Check that product discharge valve is open.
If closed, open valve.
Step 2. Start the ROWPU and note the product pressure reading when the pump shuts down If the pressure is
above 40 psig ( 1 72 kPa), the product line is plugged. Start with the product out hoses and work back to
the van until the plug is found.
If no plug is found on the outside of the van, remove the product water check valve and check it for
plugging. Unplug if plugged (para. 4-45).
If the pressure Is below 40 psig (172 kPa), notify direct support maintenance to check operation of the
product high pressure switch.
Change 7 4-31