Portable Pump Troubleshooting


Portable Pump Troubleshooting

Below are helpful tables to assist in trouble shooting a Waterous portable pump. Naturally, if the problem persists, contact the Waterous Service department and talk to one of our portable pump experts.

Priming line petcock closed (PB 18 only) Open the priming line petcock at the suction inlet of the pump body when priming.
Air leaks

Clean and tighten all intake connections. Make sure intake hoses and gaskets are in good condition. Use the following procedure to locate air leaks: 1. Connect intake hose to pump and attach intake cap to end of hose. 2. Close all pump openings. 3. Start engine and advance throttle to “FAST” position. 4. Pull the priming lever to “PRIME” position until intake pressure gauge indicates 22 in. Hg. (If primer fails to draw specified vacuum, it may be defective, or leaks are too large for primer to handle). 5. Return the priming lever to the “RUN” position and shut off engine. If vacuum drops more than 10 in. Hg in five minutes, serious air leaks are indicated. With engine stopped, air leaks are frequently audible. If engine leaks cannot be heard, apply engine oil to suspected points (intake hose connections, piping joints, mechanical seal) and watch for break in film or oil being drawn into pump.

Completely fill water tank (if so equipped). Connect intake hose to hydrant or auxiliary pump. Open one discharge valve and run in water until pump is completely filled and air is expelled. Close discharge valve, apply pressure to the system, and watch for leaks or overflowing water tank. A pressure of 100 PSI is sufficient. DO NOT EXCEED RECOMMENDED PRESSURE.
Air trapped in pump and piping. When pumping from a water tank, priming the pump may be necessary under some conditions because of air trapped in pump and piping.
Dirt on intake strainer Remove all leaves, dirt and other foreign material from intake strainer.
When drafting from shallow water source with mud, sand or gravel bottom, protect intake strainer by suspending it from a log or other floating object to keep it off the bottom. Anchor float to prevent it from drifting into shallow water.
Defective primer After prolonged service, the engine muffler, spark arrestor or exhaust primer may become plugged with carbon deposits or rust. Disassemble, then clean or replace components as required.
Engine speed too low Advance throttle to “FAST” position.
Bypass line open If a bypass line is installed between the pump discharge and water tank, to prevent pump from overheating with all discharge valves closed, look for check valve in the line. If the valve is stuck open, clean it, replace it or temporarily block off line until a new valve can be obtained.
Lift too high For high lift applications (10 feet or higher) when the pump is new, priming operation may be improved if the engine choke is engaged slightly (no more than ¼ of choke lever travel) after advancing engine throttle to full open. Once the pump is primed, return choke to the “RUN” position.
End of intake hose not submerged deep enough Although intake hose might be submerged enough for priming, pumping large volumes of water may produce whirlpools, which will allow air to be drawn into intake hose. Whenever possible, place end of intake hose at least two feet below water source.
High point in intake line If possible, avoid placing any part of intake hose higher than pump inlet. If high point cannot be prevented, close discharge valve as soon as pressure drops, and prime again. This procedure will usually eliminate air pockets in line, but it may have to be repeated several times.
Primer not operated long enough The maximum time for priming should not exceed 30 seconds for lifts up to 10 feet (3 m). If prime is not made after 30 seconds, it generally indicates a problem in the primer, piping, priming technique, or a combination of the above.
Insufficient engine power Engine requires maintanence. Check engine in accordance with manufacturer’s instruction.
Pump impeller or wear rings badly worn Check the wear hubs on the impeller for excessive wear or clearance with the wear rings. If the clearance exceeds 0.020/0.025 in., or if the impeller hubs are badly scored or grooved, replace the impeller and both wear rings.
Intake strainer or impeller vanes fouled with debris Remove intake strainer and hose and clear away all debris. Pressure backwash will usually clear impeller vanes when pump is stopped.
Intake hose defective On old intake hoses, the inner liner sometimes becomes so rough it causes enough friction loss to prevent pump from drawing capacity. Sometimes, the liner will separate from the outer wall and collapse when drafting. It is usually impossible to detect liner collapse, even with a light. Try drafting with a new intake hose; if pump then delivers capacity, it may be assumed that the previous hose was defective.
Intake hose too small When pumping at higher than normal lifts, or at high altitudes, use a larger intake hose.
Intake hose too long Position pump as near as possible to water supply.
Engine speed too low Check engine speed with a tachometer. If speed is too low, refer to engine manufacturer’s instructions for method of adjusting engine speed governor.
Pump capacity limits pump pressure Do not attempt to pump greater volume of water at a desired pressure than the pump was designed to handle. Exceeding pump capacity may cause a reduction in pressure. Exceeding maximum recommended capacity will produce cavitation and will seriously impair pump efficiency. When pumping from water tank, hydrant, or relay, always make sure the intake pressure gauge reading stays above zero.

(In general, the above causes and remedies for low pump capacity will also apply to low pump pressure.)

If you have any questions regarding this information or need any assistance, please contact us at: 
Telephone: 651-450-5200
Fax: 800-488-1228