Rislone Diesel DEF & SCR Emission System Cleaner, 1-Pack — Concentrated DEF-safe formula

If your diesel vehicle’s SCR or DEF system is showing reduced performance, limp mode events, or warning lights, crystallization and contaminants in the DEF tank and lines are often the culprits. Rislone 4784 Crystal Clean is a proprietary blend of DEF-compatible cleaning agents and surfactants designed to be poured into the DEF/AdBlue tank to break down and flush away deposits from the tank, pump, heater, sender, lines, injector, decomposition tube/reactor, and mixer.

How does this product clear DEF and SCR crystallization?

The formulation targets the white urea-derived crystals that form when DEF evaporates or degrades under certain driving conditions. It loosens and dissolves deposits so normal DEF flow and injector function can return, which helps restore proper SCR function without altering the DEF chemistry when used as directed.

• Contains surfactant detergents specifically compatible with DEF/AdBlue systems.
• Designed to reach and dissolve deposits in tank, pump, heater, lines, and mixer.
• Safe for DOC, DPF, SCR, ASC systems when used only in the DEF tank.
• Works with all approved diesel exhaust fluids (AUS 32, AdBlue, DEF UREA, etc.).

When and how often should I use Rislone DEF Crystal Clean?

Use this cleaner whenever signs of DEF system obstruction appear—warning lights, reduced engine power, or increased fuel consumption—or as preventive maintenance if you frequently drive at low speeds or on short trips. Rislone recommends repeat treatments if a fault light persists after roughly 250 miles, and routine use about every 5,000 miles to reduce recurrence of crystallization.

• Light truck / mid-to-large SUV (5–9 gal DEF tank): full bottle per service.
• Car / small SUV (3–5 gal DEF tank): about half bottle per service.
• Medium/heavy-duty trucks (10–20 gal DEF tank): use two bottles per service.
• Pour into mostly full DEF tank, then top up with approved DEF fluid; use adapter/funnel if needed.

Will using this cleaner affect my vehicle warranty or DEF fluid?

Rislone designed DEF Crystal Clean to be safe with approved diesel exhaust fluids and emission hardware, and its use will not void new vehicle manufacturer warranties when applied correctly. The product is formulated for the DEF/AdBlue tank only—do not add it to the diesel fuel tank—and it is compatible with common fuel systems and approved DEF formulations.

• Does not require changes to vehicle calibration or DEF chemistry when used as directed.
• Compatible with BlueTEC, BlueHDi, Cummins, Duramax, PowerStroke, TDI, and many other systems.
• Follow manufacturer filling procedures for vehicles with special DEF adapters.
• Seek mechanical service if warning persists after a second application.

Who is this for? Rislone 4784 DEF Crystal Clean is intended for diesel owners, fleet managers, and technicians who want a targeted, DEF-safe cleaning solution to address or prevent crystallization in SCR systems. It’s especially useful for vehicles that do many short runs, frequent stops, or low-speed operation—conditions that raise the risk of DEF crystallization. Use it as part of scheduled maintenance or when DEF-related warnings and performance issues arise. Always follow the dosing instructions for your tank size and never add the product to the diesel fuel tank.

Ingredients

Proprietary