This demonstration guide answers one field question about an unloader stuck in bypass or a failed pump packing. Measurements come before parts, and the notes are not a generic equipment FAQ.
Diagnose before replacing parts
Start with pressure at the pump versus at the gun. That reading separates an unloader stuck in bypass or a failed pump packing from adjacent faults that share the same complaint.
If the measurement is out of spec, treat the unloader or packings as the primary path. If it is in spec, do not replace the unloader or packings just to complete a parts list.
Repair the failed system
The usual correction is the unloader or packings, installed to the documented spec for this complaint.
A demonstration shop records the finding so the next technician is not repeating a guess about an unloader stuck in bypass or a failed pump packing.
Stop before you make it worse
Do not running the pump without a water supply to "prime" it. That shortcut hides the original measurement and creates a second failure.
If the machine still fails after the unloader or packings is corrected, convert the visit to a broader diagnosis rather than stacking parts.
Written and published by Ridgeline Small Engine.