Jewkot 2 PCS Car Brake Fluid Moisture Content Test Pen, Portable Brake Fluid Fault Diagnosis Test Pen with LED Indicator Light, Maintenance Test Accessory, Compatible with Most Vehicle Types (Black)

After some time with them, I’ve done a couple brake flushes, I curiously tested a vehicles brake fluid with BOTH pens i received. One pen gave me a full 5% illumination, while, the other, tested at 2%. Besides that, these are very flimsy and cheaply made. Inaccurate for Brake Fluid Testing

I ordered this tool to check my brake fluid and the tool works very well. I dipped it in my brake fluid reservoir and the tester showed that my brake fluid had an acceptable level of moisture.One thing that I noticed was that after dipping the tester in brake fluid once, you have to wipe off the metal leads before dipping it again or you'll get a false reading.This tool is affordable and is good to have in your tool box to check and see if your brake fluid needs to be changed. Highly recommended.

I tested the original brake fluid in my 15 year old 42000 mile car and got a 1% reading. I then tested it in my nearly new hybrid car and also got a 1% reading. When I rinsed the tester off in running water I also got a 1% reading in the water! Makes me wonder. I’m going to soon replace the brake pads on the old car, I think I will flush the dot3 fluid at the same time, just to be safe. The tester’s battery door cover fits great with no battery, it was a real struggle to get the cover on with a battery in the holder. I think I will take some brake fluid and let it sit in the screened in porch, exposed to humid air outside in rain and shine for a few weeks and test that before I make a final opinion.