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Hy-per Cool Radiator Cleaner & Super Flush

  • Cleans Entire Cooling System
  • Removes Deposits
  • Neutralizes Acids
  • Prevent Corrosion
  • Prevents Scale & Deposits

This is not a me-too product.

We refused to make just another radiator flush. If we couldn’t develop one worthy of the Rislone Hy-per Cool name, we wouldn’t put it in our product lineup. Simple as that.

After several significant refinements to our product formulation, what emerged from our lab was Rislone Hy-per Cool Cleaner & Super Flush, the highest-performing radiator cleaning product you can buy.

Your cooling system is insanely important, yet overlooked. Give it the attention it deserves.


Product Support:

Product Details

Part Number: HFL400

Dosage: One bottle treats up to 16 quart systems.

Size: 16 FL. OZ. (473 mL)

SDS / Tech Info:
HFL400 1212 SDS Open Download
Tech Sheet Open Download

Frequently Asked Questions

Additional Product Info

Rislone® Hy-per Cool™ Radiator Cleaner & Super Flush will help your cooling system by removing deposits that build up over time causing overheating. Heavy duty formulation is specially designed to clean solder bloom, oily residue, rust and scale. Contains water pump lubricant and corrosion inhibitors, so will not damage the pump like other brands.


  • Fast, easy and safe to use on all cooling system materials, including plastic and aluminum. Works with all cooling systems.
  • Eliminates damaging cooling deposits, reducing engine operating temperature to prevent overheating.
  • Neutralizes acids that cause corrosion and helps prevent formation of future scale deposits.
  • Heavy Duty Xtreme Clean™ formula cleans entire cooling system.
  • Removes deposits and coolant gel for a complete cleaning in 30 minutes or less.
  • Use every time changing coolant for light flushing or heavy duty cleaning.
  • Clean systems run cooler.


Never remove radiator cap if engine is hot.

One bottle treats up to 16 quart systems.

Step 1. With engine off and cool, drain system.
Step 2. Close drain and add entire contents of bottle, then refill system with water. Reinstall cap, start engine, turn heat on high, and run engine for 10 to 15 minutes. Turn engine off and allow to cool, drain system.
Step 3. Flush cooling system and reservoir until water runs clear.
TIP: Using a flush “T” with garden hose works best for final cleaning.
Step 4. Refill cooling system and reservoir with manufacturer’s recommended antifreeze/water mixture.

For best results add Hy-per Cool Super Coolant after flushing the system, as the metal surfaces inside the system are now cleaned and primed for optimal heat transfer performance and corrosion protection.

Observe local laws and regulations. Where permitted, dispose of in a sanitary sewer system. Never pour on the ground or in a storm sewer system.

Available At:

Rislone products are available where auto parts are sold.

Current Deals

HFL400 - Advance Auto - $5.00

Get your car ready for summer!  $5.00 rebate for Advance Auto customers.

Advanced Auto Parts