This demonstration guide answers one field question about an injector that leaks air into the inlet path. Measurements come before parts, and the notes are not a generic equipment FAQ.
Diagnose before replacing parts
Start with injector shutoff versus soap draw. That reading separates an injector that leaks air into the inlet path from adjacent faults that share the same complaint.
If the measurement is out of spec, treat the detergent injector as the primary path. If it is in spec, do not replace the detergent injector just to complete a parts list.
Repair the failed system
The usual correction is the detergent injector, 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 injector that leaks air into the inlet path.
Stop before you make it worse
Do not forcing soap through the high-pressure side. That shortcut hides the original measurement and creates a second failure.
If the machine still fails after the detergent injector is corrected, convert the visit to a broader diagnosis rather than stacking parts.
Written and published by Ridgeline Small Engine.