I haven't had a brake fluid flush for 18k miles or so, but I want to make sure the fluid is OK in the brake master cylinder. So I purchased a black electrode brake fluid tester, some brake fluid from the lexus dealer, but even the lexus dealer brake fluid shows as 4% on the tester (this is the second tester). This is also the second bottle of lexus brake fluid that shows as having a 3 or 4% level on the brake fluid tester (which supposedly means you need to get it replaced).
Why is the fluid directly from the lexus dealer, which is sealed and capped, giving me a moisture reading? Should I trust the tester and a get third bottle or just put in the new fluid and not worry about it? I mainly want to make sure my brake parts aren't dealing with dirty/old fluid. In a few thousand miles, I want to do a full bleed and flush but not right now.
Thank you for any and all insights.
Those electronic testers are not very reliable. Use test strips instead.
Bear in mind you will likely need a bidirectional scan tool to bleed your ABS if you'll be doing the work yourself.
There's really no need to be going to a dealer to service or buy supplies for a 26-year-old car. That is by far the most expensive option. Lexus doesn't make their own brake fluid, they just put their label on someone else's and mark it up.
@chucktobias Tried the test strips, and brake fluid seems fine. Apparently the electronic tester was no good. Thanks.