FJC 4923 Tintura ultravioleta, de 1 onza.

This is the best dye for use in r134a a/c systems. Only need 1/4 ounce per average vehicle a/c.

The garage told me I needed valve cover gaskets, it still leaked. Then the o ring on the dipstick tube, it still leaked. When they told me $650 for the oil pan gasket, I wanted to make sure. I bought the dye, put it in, and got underneath with a uv light. Turns out it is the rear main seal. I found a different garage to fix it. The dye saved me an unnecessary $650 and paid for itself many times over.

My zero turn mower began dripping fluid on the garage floor. I was needing to top off both the hydraulic fluid and oil every few weeks, but suspected the fluid on the floor was from the hydraulic tank. So I ordered this dye and cleaned the gunk off the chassis of the 23 year old mower. I dumped the dye into the hydraulic tank, cut the grass for two hours and parked the mower in the garage.I went out to the garage shortly after sunset, and the dye showed fluid had dripped from an overflow tube on the hydraulic tank. I had topped the fluid off when I started mowing for the season about a month ago and had overfilled the tank. The dye was easy to see and I was relieved that the "leak" problem was solved without a service call for the mower.EDIT: Photo added - The accompanying photo was taken

I don’t have anything to compare it to, but it worked great for me. I poured to entire bottle (1 oz) into my snowblower which holds 1.5 quarts and used the cheapest black light Amazon had available. Let it run for a minute or so and voila. You can easily see the cracked block. Guessing I didn’t need the whole bottle, but……..

I work on vintage cars where I'm often tracking down minor oil leaks. One bottle is enough, UV dye is quite apparent in leaking oil (oil capacity is usually 5 qts. UV flashlight with decent strength works fine for this purpose. If you use protective eye glasses that it isn't filtering out the fluoresce from the dye.

I used this to trouble-shoot an oil leak I was having on my project car. The dye fluoresces very brightly under UV light. I used it to confirm the location of my oil leak before I took things apart.Picture 1 shows the bottle under UV lightPicture 2 shows wear a drop got on the valve cover and I wiped it with a ragPicture 3 shows the leaking oil pump drive housing

It doesn’t say how much to add, so I read online it should be a half ounce (half bottle). I had confidence when I saw it glow on the counter in the bottle with the black light, then I added half the bottle and ran the engine for 15 minutes: while I saw no signs of leaks, I checked the oil on the dipstick and drove it. When I looked after driving I did notice a leak which I got fixed.

My brother's car had a leak somewhere within the power steering area and this dye sure helped us see how bad it was. This is surely a handy method for detecting and seeing how far those leaks go because, in my example, the fluid was reaching all the way down to his oil pan! I thought originally that the oil pan was also leaking, however, once I began to see the dye reach way down there, I was relieved we didn't have another leak on our handsTo test for consistency, you would be better off buying a second bottle to be absolutely sure the source of the leak. I remember when I was using this product, I was kind of wishing I bought another one, but this just preference