This demonstration guide answers one field question about a freeze crack through the valve cavities. Measurements come before parts, and the notes are not a generic equipment FAQ.
Diagnose before replacing parts
Start with crack map after a pressure test. That reading separates a freeze crack through the valve cavities from adjacent faults that share the same complaint.
If the measurement is out of spec, treat the pump as the primary path. If it is in spec, do not replace the pump just to complete a parts list.
Repair the failed system
The usual correction is the pump, installed to the documented spec for this complaint.
A demonstration shop records the finding so the next technician is not repeating a guess about a freeze crack through the valve cavities.
Stop before you make it worse
Do not clamping a cracked head with epoxy and a hose clamp. That shortcut hides the original measurement and creates a second failure.
If the machine still fails after the pump is corrected, convert the visit to a broader diagnosis rather than stacking parts.
Written and published by Ridgeline Small Engine.