Rislone DEF Crystal Clean Diesel DEF & SCR Emission System Cleaner, 1‑Pack — dissolves urea crystals, restores SCR dosing

Rislone 4784 DEF Crystal Clean is a concentrated DEF/AdBlue-compatible cleaner formulated to dissolve white urea crystal deposits and restore proper SCR system operation.

Vehicles with selective catalytic reduction (SCR) systems can develop hardened white crystallization from diesel exhaust fluid (DEF/AdBlue) that clogs tanks, pumps, lines, heaters and mixers. Rislone DEF Crystal Clean contains a proprietary blend of cleaning agents and surfactants developed to be safe with all approved DEF formulations while breaking down deposits that impair dosing accuracy and SCR performance. Used as directed, the product is poured into the DEF tank and works during normal operation to clean internal components, helping recover lost power and improve DEF system reliability.

How does Rislone DEF Crystal Clean remove SCR deposits?

The formula uses surfactants and solvent action to dissolve and loosen the white urea-based crystals that form from DEF evaporation and decomposition. As the vehicle operates, the cleaner circulates through tank components and lines, softening deposits so they can be flushed or re-dissolved into the fluid.

• Targets deposits in tank, pump, heater, sender, lines and mixer.
• Safe for DEF/AdBlue-compatible materials and sensors.
• Works while driving — no disassembly required for many cases.

How do I use it correctly for my vehicle?

Install Rislone DEF Crystal Clean only into the DEF/AdBlue tank (usually marked with a blue cap) — never into the diesel fuel tank. Dosage depends on DEF tank size: one full bottle for many light trucks and SUVs, half a bottle for smaller cars, and multiple bottles for large commercial tanks.

• Car/small SUV (3–5 gal DEF tank): about 1/2 bottle recommended.
• Light truck/mid‑to‑large SUV (5–9 gal): use one full bottle.
• Medium/heavy duty (10–20 gal): use two bottles; pour into mostly full tank or add then fill.

When will I see results and what if the light stays on?

Many drivers notice restored performance and reduced DEF-related faults within a few hundred miles as the cleaner dissolves deposits. If the DEF or check-engine light persists after roughly 250 miles or several days of normal driving, repeat application or seek mechanical diagnosis to address sensor or hardware issues.

• Allow about 250 miles of driving for the cleaner to circulate and take effect.
• Second application may be required for heavy crystallization.
• If faults remain, a technician should inspect sensors, lines or modules.

Is this product compatible with my DEF fluid and vehicle systems?

Rislone DEF Crystal Clean is designed to work with all approved diesel exhaust fluids (AdBlue, AUS 32, ARLA 32 and branded DEF types) and is formulated to be safe for vehicles equipped with DOC, DPF, SCR, ASC and ammonia slip catalysts. Use only in the DEF tank to avoid contamination of diesel fuel and drivetrain components.

• Safe with AdBlue, AUS32, ARLA32 and branded DEF fluids.
• Compatible with vehicles using SCR, DPF and DOC exhaust systems.
• Will not void new vehicle warranties when used as directed.

Who is this for: Rislone DEF Crystal Clean is intended for owners and fleet managers of diesel cars, SUVs, light trucks and commercial vehicles experiencing DEF crystallization, SCR dosing faults, reduced engine power or limp-mode events related to DEF system blockages. It is especially useful for vehicles driven at low speeds, with frequent stops, short trips or light loads — conditions that promote DEF crystallization. Follow vehicle-specific filling procedures and use the correct dosage for your DEF tank size to maximize cleaning effectiveness.

Ingredients

Proprietary