TSI Supercool HFO-1234yf Total Leak Stop Plus with U/V Dye — 1 Can, Quick-Connect Hose, Non-Polymer Formula

TSI Supercool 39241B-YF Total Leak Stop Plus U/V Dye is a one-can treatment that seals small leaks and adds U/V dye specifically for HFO-1234yf automotive A/C systems.

Designed for modern vehicles that use HFO-1234yf refrigerant, this product targets minor leaks in metal and rubber A/C parts without harming system components or recovery equipment. The can uses a patented HFC-free BOV delivery system and includes a quick-connect application hose, making it straightforward to apply at the low-side service port when the vehicle is being serviced. It lubricates internal components while leaving no polymer residues that could interfere with system performance or reclamation.

How does this stop leaks without damaging my A/C system?

The formula is engineered to flow with HFO-1234yf refrigerant and deposit a sealing agent only at leak sites, avoiding the heavy polymers that can clog lines. It is compatible with both metal and rubber components and will not affect recovery/recycling equipment when used as directed. Note: it is not compatible with R134a systems.

• Seals small leaks in evaporator, condenser, hoses, gaskets, O-rings
• Non-polymer formula reduces clogging risk
• Safe for hybrid and electric compressor designs
• Works only with HFO-1234yf (not for R134a)

What’s included and how do I apply the can?

Each package contains a single overfilled can of leak stop plus a HFO-1234yf application hose with a quick-connect coupler. Application is made at the low-side service port; the quick-connect should fit snugly—if it does not, don’t force it because that indicates an R134a port. The product includes a QR code linking to a short installation video for step-by-step guidance.

• One overfilled can per vehicle for full treatment
• HFO-1234yf specific quick-connect application hose included
• Patented HFC-free BOV delivery system for controlled injection
• QR code on box for installation video

Will adding this improve system lubrication or performance?

The formula contains lubricants that help condition seals and moving parts, which can reduce wear and support optimal compressor operation. While it’s intended to assist system reliability and longevity, results vary by leak size and system condition; larger leaks require professional repair. The product is formulated to avoid residues that could interfere with future service.

• Provides supplemental lubrication to O-rings and seals
• Helps maintain compressor-friendly environment
• Doesn't leave harmful residues that impede service
• Not a substitute for repair of significant leaks

How can I confirm this will fit my vehicle’s service port?

HFO-1234yf low-side service ports have a larger diameter than R134a ports; the included quick-connect coupler is sized for HFO-1234yf. Before connecting, visually inspect the port and ensure the coupler seats snugly—an improper fit indicates an incompatible refrigerant system. If uncertain, consult the vehicle service manual or a technician to confirm refrigerant type.

• Quick-connect coupler sized for HFO-1234yf low-side port
• Snug fit required—loose fit means incompatible system
• Check vehicle manual or refrigerant label to verify HFO-1234yf
• Do not use in R134a systems

Who is this for: TSI Supercool 39241B-YF is intended for DIYers and automotive technicians working with HFO-1234yf air conditioning systems who need a single-can solution to stop minor leaks and add U/V dye for leak detection. It’s suitable for cars and light trucks that explicitly use HFO-1234yf refrigerant, and for owners who want a product that lubricates seals without leaving problematic polymers. It is not appropriate for vehicles that use R134a or for systems with major refrigerant loss that require component replacement.