TSI Supercool Synthetic U/V Leak Detection Dye, 1 oz, 1 Application

This stuff worked great, one ounce was more than enough. For those who said the product didn’t fluoresce in the bottle, I believe it needs to mix with the coolant/water to really light up. Remember this is to be used with a black light/UV light to see the leak. While it was bright enough to see some areas with no artificial UV light, it is ideally used with a UV light. Super bright for me, showed the leak clearly and was in an area that I never would have thought of or found without the leak detector.

I had a coolant leak. My mechanic said that they couldn't determine where the leak was because it was very slow. After a while, the rate of leaking increased. Rather than using a leak-seal product, I wanted a real fix, so I added this dye and drove around. My mechanic said that the dye made it very easy to see where the leak was. This saved a considerable amount of diagnostic time... and saved me a considerable money. It was really easy to use. The only issue was that my mechanic said that the dye had made a mess on the bottom side of my truck.

Works good, found puddle under my thermostat housing and made noticing the weep hole spewing water from my pump a lot easier. Very bright and could instantly notice it after running the car for a couple of minutes.

Stuff worked awesome... so much so it made my gold coolant a neon green. Was worried at first since it didn't fluoresce on its own but once added to other fluid ie coolant it became super neon. Bought a blacklist and it found my leak on a 2010 Explorer.

Worked fine. Isolated the leak. Thanks!

Everything arrived as advertised. I haven't used it yet but looks to be perfect! I will post pictures after I use it.

This worked great! Found the leak after a quick drive in my truck and only to isr a little bit. Sadly, the leak is turbo lines that are not very accessible... Be sure to get a good uv light or you will need to wait until it is dark out to see it pop, as my little $3 one didnt put out enough light during the day. Then, if like mine, it will look like glow in the dark splatter paint and GLOW.

Dumped it in the coolant reservoir and worked perfectly to find my coolant leak with a blacklight. Best part is that your coolant looks like toxic waste afterwards.

Sooooo very concentrated and BRIGHT. This product helped me diagnose a gremlin in my coolant system. 5/5 stars, great product.

The only Radiator specific dye that i could find. All others are for oil and are not compatible with coolant. It works amazing and it glows really bright fluorescent yellow under 365nm uv light form a cheap torch. The ammpount was more than enough for a very large LR4 V8 with dual AC system.

Did exactly what it was supposed to do. Works best when you check at night using a black light torch (only needs a small torch) Confirmed my thoughts and proved the garage wrong (saved me a lot of time and money).

Very strong, only need a little bit to make all of the coolant extremely uv visible. Helped me find my leak

Works really well, even without a black light you can clearly see the leaks, recommend.