[Gelbster]

Originally Posted by Lew

Wal Mart has this item priced right, and with free shipping. Pelican wants 40+ for the same tester. Ordered mine today!

https://www.walmart.com/ip/Brake-Fluid-Moisture-Tester-Auto-Car-Truck-Diagnostic-Testing/169181238

Even cheaper on Flea Bay.
In theory you could use a sensitive Multimeter if someone would tell us the correct setting.It is just a conductivity measurement