Reconditioning an existing system: Rad Clean, Reboot, PrimoPrep
This is the complete protocol for reviving a loop that has already run coolant — after a fluid swap, a build that sat too long, or a loop you bought used and want to trust. Three layers, in order: Rad Clean strips flux and oxidation from the radiators, System Reboot deep-cleans the whole loop of old dye and biological buildup, and PrimoPrep chemically re-stabilizes the pH before your next fill. Do not rush the soak or circulation times — cutting them short leaves old residue only partly neutralized.
PrimoChill is not liable for hardware damage incurred during the cleaning process; use at your own risk.
Read the whole guide first
This is a multi-day sequence with three different chemistries in it. Read to the end before draining anything, and lay out every bottle where you can see it.
Running a step out of order here is worse than in a fresh build — you are working on top of years of accumulated residue, and undoing a mistake means starting a stage over.
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Keeping It Cool is the technical library of PrimoChill. Products ship from primochill.com.
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