My owners manual recommends brake fluid changes every 2 years. That seems to be WAY overkill. I have had cars that I didn't change the brake fluid for 15 years and nothing happened. I know brake fluid absorbs water, but is it really that significant after only 2 years?
Overkill fits or “money maker” is another. Brake fluid does absorb moisture. How does it get there? Most brake reservoirs are designed to see the fluid level without removing the cap. If your fluid can’t last 5 years then something (likely owner) keeps opening the reservoir to “look” in there. In my opinion not only is this a money maker it’s “recreational maintenance “. So if it makes the owner feel good then have at it. It makes the shops a quick buck. i’d rather eliminate the risk of rounded off and/or bleeders left loose.
I'm going to ask a dumb question for the chemists here. Brake fluid is basically mineral oil, right? And if mineral oil absorbs moisture, does motor oil absorb moisture as well?
I'm going to ask a dumb question for the chemists here. Brake fluid is basically mineral oil, right? And if mineral oil absorbs moisture, does motor oil absorb moisture as well?
Haynes explains: what Is brake fluid and what are the DoT numbers?
haynes.com
The DOT brake fluid is glycol based which I don't think it is mineral.
There are some brake that require mineral brake fluid but I think what we are talking about here is the glycol based Brake fluid.
The Glycol based fluid is the one that is hygroscopic.
Overkill fits or “money maker” is another. Brake fluid does absorb moisture. How does it get there? Most brake reservoirs are designed to see the fluid level without removing the cap. If your fluid can’t last 5 years then something (likely owner) keeps opening the reservoir to “look” in there. In my opinion not only is this a money maker it’s “recreational maintenance “. So if it makes the owner feel good then have at it. It makes the shops a quick buck. i’d rather eliminate the risk of rounded off and/or bleeders left loose.
Brake Fluids by EBC Brakes product information page. EBC offer four grades of brake fluids separated into two families, Glycol fluids & Silicone Fluids.