Hello everyone,Me and a pal are having a friendly disagreement over a case of beer. If you could please help us settle this, I’d like to enjoy my beer without any whining. I’ll withhold my personal opinion on the matter to avoid any potential conflict of interest. If you can respond with a simple True or False to the “facts” below we would be interested in your thoughts.

  1. Brake fluid only needs to be changed when the color is dark, or the fluid has absorbed too much water. If neither of these conditions are met, the fluid is fine, regardless of mileage.

  2. When changing brake fluid, it is perfectly acceptable to remove the fluid from the master cylinder using something as simple as a turkey baster, then refilling it. Bleeding the brake lines is unnecessary.

2a) If you are concerned with bad fluid in the line, you can use the brakes for a bit, and change the fluid again. This is acceptable.

  1. If you do drain brake lines, simply tighten using the “two finger bounce” method on your wrench - pump the brakes and check for leaks. Looking up the torque spec is completely unecessary.

Thanks for any and all responses!

  • RickMN@alien.topBEnglish
    1·
    10 months ago

    The base chemical in brake fluid does not deteriorate. But the anti-corrosive and buffering additives do break down and when that happens, you get internal corrosion. In addition, all brake fluid in all brake systems absorb water, even though it’s theoretically a sealed system.

    Color, by itself, is NOT an indication of brake fluid condition. That’s a total myth. Brake fluid can turn dark due to aging rubber components, but that does not always mean the fluid is bad; just means it’s picking up coloring from the rubber. Recommending a brake fluid flush by color alone, with no other testing is a scam.

    There are several ways to test the condition of brake fluid: pH strips tells you the condition of the buffering agents. Copper test strips tell you the condition of the anti-corrosion additives (more copper in the fluid when the additives are depleted). And, a moisture meter to tell you how much water is in the brake fluid.

    You can use a turkey baster to remove and replace the fluid from the reservoir. The new fluid will mix with the old fluid and over time some of the degraded fluid will wind up in the reservoir and then you’d have to repeat the procedure. The turkey baster method just manages to dilute the old fluid a bit and add some more additives. But it’s not a replacement for a flush, just like using a turkey baster in the coolant reservoir isn’t a replacement for a cooling system flush. Internal corrosion to brake lines and ABS valves is very costly. Cheaping out with a turkey baster is better than nothing, but not by much.

    Overtightening the bleeder valve can cause problems down the line. But I’ve never in my entire time in the industry seen a single tech use a torque wrench on a bleeder screw.