ENVIRO-SAFE AC Stop Leak ProSeal XL4 Cartridge — Direct-Inject Sealant with UV Dye for 1.5–5 Ton Systems

ENVIRO-SAFE AC Stop Leak ProSeal XL4 is a direct-inject cartridge that seals small refrigerant leaks and simultaneously deposits UV trace dye for rapid detection across R410a, R22, R32, R134a and other common refrigerants.

ProSeal XL4 combines Enviro-Safe’s long-running leak-sealing formula with integrated UV dye so a single service action both attempts to stop a pinhole leak and leaves a visible tracer for inspection. The product is designed for residential and light-commercial systems — central air conditioners, heat pumps and mini-splits — and injects without a pump-down, saving time and tools for HVAC technicians. It is compatible with common compressor oils and manifold equipment, and is not intended for CO2 or ammonia systems.

How quickly does ProSeal XL4 work when added to a system?

Installation is fast: connect the cartridge to the low-side port, open to system pressure, then run the unit for about 45 minutes. The sealant and UV dye circulate together immediately, and most technicians can complete the entire service during one site visit.

• Direct-inject—no separate pump-down step required.
• One trigger pull releases the formula and dye simultaneously.
• Typical run time: 45 minutes on a running system.
• Disconnect and observe; no repeat application is normally necessary.

Which refrigerants and systems is this cartridge compatible with?

ProSeal XL4 is formulated to work with a broad range of residential and light-commercial refrigerants including R410a, R22, R32, R454B and R134a. It is safe for systems that use TXVs, capillary tubes, Schrader valves and common oils; it is not suitable for ammonia or CO2 refrigeration systems.

• Works with R410a, R22, R32, R454B, R134a and similar refrigerants.
• Safe for TXVs, expansion devices, and manifold gauge use.
• Compatible with mineral and synthetic compressor oils.
• Not recommended for ammonia (NH3) or CO2 (R744) systems.

Will adding this product harm system components or void warranties?

Enviro-Safe’s ProSeal formula has been used in millions of installations without reported warranty voids. The UV dye is the same grade used by automotive manufacturers, and the cartridge is blended to strict standards to avoid interference with valves or recovery equipment.

• No known warranty voids in over 3 million installs.
• UV dye is factory-grade and safe for diagnostics.
• Designed to be compatible with recovery and manifold tools.
• Manufactured in the USA to controlled blending specifications.

How does the UV dye help find leaks after sealing?

The dye circulates with the refrigerant and highlights every path the fluid takes; any leak site will fluoresce under a UV lamp so a technician can see where the refrigerant escaped. If the dye appears and the site holds, you’ve confirmed the leak location; if leakage continues, the glowing trace guides repair actions precisely.

• Dye travels with refrigerant for complete system coverage.
• Leaks fluoresce under UV light for quick identification.
• Helps determine whether a seal succeeded or further repairs are needed.
• Eliminates a separate dye injection step—one cartridge does both jobs.

Who this product is for: ProSeal XL4 is built for HVAC professionals and experienced service technicians who need a fast, reliable method to both attempt a pinhole seal and identify the leak location in residential and light-commercial AC, heat pump or mini-split systems. It is also useful for facility maintenance teams who want to minimize downtime and reduce diagnostic time. Do not use on ammonia or CO2 refrigeration systems; when in doubt, consult manufacturer guidance and local codes before service.