Hale Rear Mount - Manual (Page 9)

2. Air Leaks. A frequent cause of low performance, recognized by excess motor speed, hose
pulsation and unsteady pressure gauge.
Remedy - check pump for holding vacuum, find leaks.
Sometimes these leaks are in the booster tank plumbing. Leaks can usually be heard when the
motor is stopped. See instructions. Priming will be delayed by an excessively leaking packing
gland.
3. Suction obstructions. These cause higher than normal engine speed and reduced capacity.
They also cause fluctuation of the pressure gauge and a high vacuum reading on the
compound gauge.
The obstructions may be foreign matter such as grass or leaves on the suction hose strainer or
in the pump suction tube strainer. To check the strainers, shut down and open a discharge
valve very slightly, letting the water run back down the suction hose slowly. This will prevent the
foreign matter from being flushed out so that it can be observed and the cause of the trouble
determined.
The obstruction may be caused by a collapsed suction hose lining. Old or defective suction
hose may have a loose lining that is pulled inward by a vacuum, substantially reducing the flow
through the hose. It is difficult to see because the lining usually goes back into place when the
hose is removed. Usually, however, there appears to be a low blister on the lining where it has
pulled away from the carcass of the hose.
Remedy - replace the defective hose.
4. Foreign Matter in the impeller. This causes higher than normal engine speed and reduced
capacity. However, it does not cause an abnormally high vacuum on the compound gauge. To
clean foreign matter out of the impeller, remove the suction tube and push the obstruction out
of the impeller with a rod by hand. When the pump is open, it is well to check the “clearance” or
“sealing” rings for abnormal wear. See “Worn Clearance Rings and Impeller Hubs”.
5. Lift too High. This will cause high engine speed, high vacuum, pump roughness and a pulsating
pressure gauge.
Remedy - do not test at over 10 feet lift, with not more than 20 feet of suction hose.
NOTE: Larger pumps are rated at 6 feet of lift. Check pump rating chart.
6. By-Passing Around Pump. Recognized by reduced capacity and greater than normal throttle
opening.
Cause - relief valve control set at too low a pressure allowing main relief valve to
bypass.
Remedy: Reset control so relief valve closes. Booster tank fill line open. (Close this).
Leaking valves in plumbing.
7. Worn Clearance Rings and Impeller Hubs. Since clearance ring replacement requires pump
disassembly, it is advisable to thoroughly check other possible causes of low-performance
before assuming that clearance ring wear is the cause.
Clearance rings or “sealing” rings allow a negligible amount the internal bypass of water from
the discharge side of the pump back to the suction. The radial clearance between the impeller
hub and the clearance rings is only a few thousandths of an inch when new, effectively
preventing a large bypass. In clear water they continue to effectively seal for hundreds of hours
of pumping. In dirty or sandy water, the impeller hub and clearance ring will wear faster than in
clean water. The more they wear the greater the bypass and the lower the performance. Also,
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