Shallow Well Pump Pressure Slowly Dropping: Mainline Leak

Goulds 1 HP Pump Pressure Drops 60→51 PSI Over Cycles: Leak in Mainline

New Goulds 1 HP shallow well pump with pressure tank, check valve. Ran sprinklers twice—pressure slowly drops 60 to 51 PSI. Solenoids clean, pipes clean.

Diagnosis: Mainline Leak

Gauge dropping = water leaking from pressurized mainline. Common—half of systems have small leaks.

Not Critical Unless...

• Visible wet spots
• Property damage
• Pump cycles excessively

Monitor & Find

Watch pump cycle frequency. Check valve boxes (green lids) for water. Leak will worsen—eventually visible.

Critical: Gauge Must Be AFTER Check Valve

If gauge is before check valve, ignore all above—different problem.