CoolCut40air Parts Substitution Card

This is the quick external-parts substitution card for the highest-value CoolCut40air torch-front-end, air-package, and valve splits.

Use This Card When

Complaint branch	Swap first	If the complaint follows the part...	If the complaint stays with the machine...
internal-mode-only complaint	stable external-air comparison and clean internal-air package	keep diagnosis in the internal-air branch	move deeper only if both modes now fail
both air paths flow together	clean the external valve path, use backward purge if needed, and retest with known-good air	keep diagnosis in valve contamination or air-package branch	move to control logic only after the air path is proven
poor cut with moisture signs	dry air path and fresh SG55 front-end stack	keep diagnosis in air and consumables	move deeper only if the baseline stays poor
no start in both modes with healthy externals	hold the external path steady and retest	keep diagnosis internal only after the external path is clean	move to control or power branch

Stop if the complaint exists in only one air mode.
Stop if drying the air package restores cut quality.
Stop if backward purge or valve cleaning changes the symptom immediately.
Stop using the card and open the full guide if mode split, air package, and torch branches are already proven clean.