DEI Radiator Relief Cooling System Flush - 16 oz

Radiator Relief Flush is a concentrated detergent cleaner for the cooling system, not a coolant and not a sealer. It attacks rust, scale, and mineral deposits in the radiator core and hose lines and breaks down the oily residue that collects in aged antifreeze, then carries all of it out when the system is drained. DEI directs you to drain the radiator, add the bottle, top up with water, run the engine for 15 minutes with the heater on and the air conditioning off, then drain again and refill. Distilled water is recommended for the refill.

Specifications

Documents: Installation Instructions (PDF)  |  Safety Data Sheet (PDF)

Shipping

• In-stock orders placed before 3 PM EST ship the same day — everything else ships within 24 hours.
• Standard, expedited, and overnight options at checkout.
• Oversized items ship by freight and take longer.
• Backordered items ship as soon as stock lands — contact us for lead times.
• International orders: prices do not include VAT, duties, or import fees. Your country charges these at import and they are the buyer’s responsibility.

Returns

• 30-day returns on new, uninstalled items in original packaging with all hardware.
• Standard returns: 8% restocking fee, buyer pays return shipping. Both waived if the item is defective or we made the error.
• Installed or used parts can’t be returned — confirm fitment before you install.
• Special orders and custom items are final sale.
• Email us for return authorization before shipping anything back.

Full details: Shipping Policy · Refund Policy