by Pat Goss
No matter how fast your car is, you still have to be able to stop it. And that means that you have to have good brake fluid in that car. Now, if we look at these jars of brake fluid, which we’ll start right here: this is new brake fluid. No question about that. But, brake fluid has a very nasty characteristic, and that is that it attracts and absorbs water. So here we have a jar that is half water; 50% water. Yet you look at it, and it really doesn’t look that much different than the brand new fluid. So you can’t just look at it and go, “hey it’s good.”
Certainly, if you look at it and it looks like this one over here, it’s dark colored and so on; it needs to get out of the car right away. That means that you have to have the system flushed. Well, the real thing that you should be doing is flushing the brake system every two years. Don’t go beyond two years. You see, if you flush the brake system, the fluid will be kept clean and dry, and that means you’ll have a safer braking system and the hydraulic parts in that brake system will last a lot longer. But when you take the car to the shop to have the brakes flushed, you’re going to be asked some questions. There are different types of brake fluid. There’s DOT3, there’s DOT4, there’s DOT5. Now, DOT3 and DOT4, you could replace DOT3 with 4 in some cases, but you could never replace 4 with 3. So, you have to look at the cap on the master cylinder, to see what’s appropriate for your car. And make sure that the technician uses the proper fluid for your car.
But DOT5; DOT5 is silicone synthetic fluid. And it’s typically not used in modern automobiles. Now it’s dyed this purple color so that you can readily identify it, so it doesn’t get mixed up with conventional fluid. But the reality of this stuff is, it doesn’t absorb moisture, but in a modern car, it doesn’t work well with ABS brake systems. The pumping action can cause it to foam in some cases. So for older, collectible cars, where you want to keep moisture out of the systems, and you don’t have ABS, DOT5 might be the answer.
Big thing: flush your brakes every two years. And you’ll have safer brakes; you’ll have brake parts that last a lot longer. And if you have a question or comment, drop me a line, right here at MotorWeek.