This demonstration guide answers one field question about solvents that swell or crack packings. Measurements come before parts, and the notes are not a generic equipment FAQ.
Diagnose before replacing parts
Start with seal durometer versus a new packing. That reading separates solvents that swell or crack packings from adjacent faults that share the same complaint.
If the measurement is out of spec, treat the packings as the primary path. If it is in spec, do not replace the packings just to complete a parts list.
Repair the failed system
The usual correction is the 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 solvents that swell or crack packings.
Stop before you make it worse
Do not drawing automotive degreaser through the pump. That shortcut hides the original measurement and creates a second failure.
If the machine still fails after the packings is corrected, convert the visit to a broader diagnosis rather than stacking parts.
Written and published by Ridgeline Small Engine.