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Preps & treatments

Coolant is not a cleaner. Every one of these exists so the fluid you fill with can do its actual job instead of scrubbing your loop. Two kits if you want the decision made for you, five bottles if you want to build the sequence yourself.

Start here

Which one do I need?

Brand-new parts, nothing has ever run through the loopComplete Prep Kit — New SystemRad Clean → SysPrep → PrimoPrep
Rebuilding a loop that has already run coolantComplete Prep Kit — Existing SystemRad Clean → System Reboot → PrimoPrep
New radiator, you already have fill-port fittingsRad Clean — StandardOne bottle per radiator
New radiator, you don't have fill-port fittings yetRad Clean — Full KitConcentrate + fittings + funnel, all in one
Switching from an opaque fluid to a clear oneSystem RebootLifts dye staining as well as residue
Annual service on a healthy loopRad Clean + SysPrepRadiators, then a full-loop pre-treat
Mixed-metal loop with a large copper radiatorPrimoPrepControls the copper-driven pH swing
Neglected loop, heavy residue, pre-treatment will not cut itSystem SoapThen re-prep from the top
Inside the loop

Three things are trying to ruin your coolant right now

This is what every bottle above is defending against. The mechanism, the visible symptom, and the product that stops it.

Galvanic corrosion at every metal junction

Put copper and nickel in the same wet circuit and you have a battery. Electrons move from the less noble metal to the more noble one, and the nickel plating on your block starts to lift in flakes you will find in the reservoir six weeks later. Temperature accelerates it: a loop that idles at 45 °C corrodes faster than one that never leaves 30 °C.

Onset
Weeks to months
Reversible
Partly
Product
Liquid Utopia
The fix

Liquid Utopia carries a corrosion inhibitor package that plates a molecular barrier onto exposed metal. 15 ml per gallon of DI or distilled — under-dosing is worse than not dosing, because a partial film leaves anodic hot spots.

TUBE CROSS-SECTIONNickel plating lifting at the fin root
Why any of this

A coolant used as a cleaner is a coolant that clouds.

Every block, radiator and fitting arrives with something on it — machining oil, casting flux, cutting debris. If the first thing to meet that residue is your coolant, the coolant spends its inhibitor package cleaning instead of protecting, and you see the result as a film at week three.

Prepping is ninety minutes. Not prepping is a teardown, and it is almost always blamed on the fluid.

Changing coolants? Do this.

01Drain completely, from the lowest point
02Rad Clean through every radiator
03System Reboot if the old fluid was opaque
04Distilled rinses until runoff is clean
05SysPrep, then fill with the new coolant
PrimoChill

Keeping It Cool is the technical library of PrimoChill. Products ship from primochill.com.

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