– ZKTOOL Upgraded Automotive Brake Fluid Tester Pen for DOT3 DOT4 DOT5 | Universal 5 in 1 Detector ENV6 ENV4 Oil Detection Pen, 5 LED Indicator Light, Premium Brake Fluid Moisture Analyzer Tool

Worked remarkably well

Very easy to use. Seems accurate too. I tested several cars with differing ages of brake fluid and it clearly indicated correct variations of % value. Good product for the money.

I like gadgets & this is a useful tool to check brake fluid, the only problem was there were no batteries in the pack (maybe they didn’t get put in by mistake)

Easy to use & until I have used it on more than 1 can't say much more, light weight

Good quality Working fine

Works as said

I dislike being prompted to write a review when I have barely had time to open the package, so this rating might change. If this device is accurate it could merit 5 stars. Perhaps it is. I tested one of my cars a couple of days after the fluid was renewed and sure enough it read 0% water. I tested a second car that I know has not had a change for at least 4 yeaes and got a 0% reading from that. A third car came up as 3%-4%. I don't know when that was changed but it is a deeper colour which usually indicates older fluid. So it could actually be telling the truth. Be aware that you need to set the fluid type. I don't know how one can know this if one didn't put the fluid in ones self. Most cars would be happy with DOT3 but most fluid on sale now is DOT4 that meets or exceeds DOT3 requirements. So I suggest assuming it's DOT4. Garage test machines are £200 or more. Maybe this is because they actually test the boiling point? New DOT4 boils at circa 260C apparently. This drops to around 160 with 3% water. I only know personally of 2 people who have boiled their brake fluid. One is my brother who did it over 40 years ago in a car with probably 13 year old dark brown brake fluid. The other has a Porsche 911 with recent fluid that is almost clear. But by the law of averages most of us probably be ok if we drive sensibly. Assuming it's working ok, the only criticism I have at this price is that it automatically shuts off too quickly. Does that help?

Good piece of equipment needed in a garage

Leicht verständlich

Werkt prima. Snel resultaat…

Cumple sus funciones a la perfección

Works perfect

Indispensable pour tester la teneur en humidité du liquide de frein, fonctionne parfaitement. Simple d’utilisation et résultat instantané et très explicite. vert Ok Orange pensée a remplacer Rouge danger Et avec plusieurs led et graduation très simple à interpréter .