Brake Fluid Liquid Tester Pen,1PC DOT 3 DOT 4 DOT 5.1 Brake Fluid Liquid Tester Pen, Car Diagnostic Testing Tool with 5 LED Indicators, Hydraulic Fluid Liquid Oil Moisture Analyzer

I have multiple vehicles and wanted to know how they brake fluid condition is, besides a visual inspection. This allows me to test how much moisture has contaminated the brake fluid, and it works too. I tested it on a car that I knew had very old and dirty brake fluid and all the lights lit up, indicating it desperately needs changing. After I flushed all the old fluid out with new fluid I tested it again and only the first light came on. Now I can check my brake fluid a couple times a year, especially on a performance car where the moisture can boil and cause brake face under intense conditions.

Seems to work just fine to check the water content of the brake fluid so I am happy. Thanks to all!

Cheaply Made But Works

Used it once. Gave me a reading. Seemed to work just fine.

Would buy again

Item worked backward. I put it in a unopened bottle of brake fluid I got from Amazon and had the worst reading saying moisure was >4%. Then I put the probe in the brake fluid in the reservoir of my truck that I was about to change and it said the moisture was 0% although the fluid was 7 years old in my vehicle.

I can’t really say if I trust this. If you dip this into some very obviously old fluid that is compressing and in need of replacement, it will light up somewhat green. If you run it under water though, it will show red. So clearly it works and can detect moisture, but on the side of detecting it in brake fluid and knowing when it’s too high, im not sure if I’d rely on it.

Good little product works as discribed.