Radiators arrive dirtier than any other part of a loop and they are the hardest part to inspect. This is the standalone procedure, it is step three and four of a full system prep, written out for when you are only doing radiators. One bottle covers up to 8 radiators, and this only ever happens outside the case, before the radiator goes anywhere near a running loop.
PrimoChill is not liable for hardware damage incurred during the cleaning process. Use Rad Clean at your own risk, and never inside a running loop.
Fit plastic port caps and o-rings before you put anything in the radiator. Set your metal fittings aside for now.
Rad Clean is formulated for the internal metals of a radiator and is not compatible with nickel or aluminum. Nickel-plated fittings will take cosmetic damage from the hour in the radiator.

Keeping It Cool is the technical library of PrimoChill. Products ship from primochill.com.
© 2026 PrimoChill · Made in the U.S.A.