Liberty Pumps 404 Manuel D'installation page 5


Pump runs
periodically when
fixtures are not in

use.

Water or soap suds

come out of vent
pipe.


Pump operates
noisily.

PERFORMANCE CURVES AT 80° F WATER TEMP
40
35
30
405 @ 180°F
25
20
15
MODEL 404
10
5
0
0
Check valve was not installed, is
stuck open, or is leaking.
Faucets are dripping.
Vent pipe is too short or too small in
diameter.
Defective switch.
Rate of in-flow exceeds pump
output.
Foreign objects in impeller cavity.
Piping to house structure is too
rigid.
MODEL 404 AND 405
10 20
FLOW (GPM)
Figure 5: Performance curves for 404 and 405.
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
Remove and examine for freedom of
operation and proper installation.

Repair faucets to eliminate dripping.

Be sure that an unrestricted vent at least 1-
¼" in diameter is in use.

*Remove tank cover and check that float is
free to move. If build-up restricts float, clean
and reinstall. If defective, replace switch.

Use valve on the inlet to reduce rate of inflow.

*Disassemble the receiver and bottom base
of pump. Remove foreign material.
Reassemble.

Replace a portion of the discharge pipe with
rubber hose to absorb noise.
MODEL 405
30 40 50 60
5