Brake Fluid

I was at the car dealer and they told me that my brake fluid needed to be flushed/changed because it was really dirty.

Is this necessary? I’ve asked a few people and they never heard of doing that.

It was never a “must do” until the Euro’s started doing it. Now it’s the law (just kidding). It’s never been an issue for as far back as anyone can remember.

NOW that ABS is in just about every car, it’s a wise move. The remanufactured units can cost upwards of $1200.

I will never consider this a safety issue. It’s a system longevity issue. You’ve never EVER heard of someone having an accident due to not flushing their brake fluid.

I don’t have ABS brakes, is this still a longevity or safety issue?

Brake fluid flushing is important and it can be a safety issue.

Brake fluid is hygroscopic, meaning it will absorb moisture over time. That moisture can cause problems in two ways:

1: It will accelerate pitting and corrosion in the master cylinder, wheel calipers/cylinders, and in the ABS system.

2: Under demanding braking applications (mountain driving, heavy braking loads), the brake fluid can heat up. Any increase in moisture in your fluid will lower the boiling point (by up to 100 degrees F). Brake fluids with lowered boiling points will boil under demanding braking - resulting in braking problems or failure.

Some folks do fine without changing their brake fluid. I’ve always been an advocate for changing it every few years.

How old is the car? I keep mine for a long time and drive them into the ground. I’ve been finding that after a decade or so, the flexible hoses that connect the hydraulic system to the front wheels start to deteriorate and the brake fluid gets discolored and gritty. At that point, it’s probably time to replace both the brake hoses and the brake fluid. If you don’t replace the hoses, they will eventually fail – very likely by causing the brakes to fail to release at times.

That said, a lot of cars go to the scrap yard with the same brake fluid they left the factory with.

You did not tell us what make model and year your car is. When was the last time your brakes were serviced and was was done? Has the fluid ever been replaced.

Yes it is important to replace that fluid from time to time. However assuming the warranty is up, there is no reason you need to have the dealer do that work. Usually you can find a local independent mechanic. Ask your friends, neighbors, relatives and co-workers for a recommendation.

Dealers tend to be more expensive, and for the most part no better than an independent. However the independent will almost always cost less.

Read that owner’s manual! Get any maintenance that is past due done.

Remember that brakes are kind of important.

Brake fluid is hygroscopic, meaning it will absorb moisture over time.

As it has been since put into use. Never needed flushing for the lion’s share of 50 years.

That moisture can cause problems in two ways: 1: It will accelerate pitting and corrosion in the master cylinder, wheel calipers/cylinders, and in the ABS system.

AKA: System longevity issues.

2: Under demanding braking applications (mountain driving, heavy braking loads), the brake fluid can heat up. Any increase in moisture in your fluid will lower the boiling point (by up to 100 degrees F). Brake fluids with lowered boiling points will boil under demanding braking - resulting in braking problems or failure.

Which are unheard of in a properly maintained system that gets a routine relining and bleeding (on average) every two years. Most people need brakes every other annual safety inspection. Some, every year.

It’s the pad slapping DIY’r that needs to worry here. I’ve never had to turn a rotor on a car that I drive since I preemptively change pads. I never disturb the hydraulics. I’m the guy who needs to flush his system.

You do realize that the brake service industry self promotes the continuous complication of a system that’s worked well for over 40 years (disc brakes), don’t you? Endless evolutions of stuff that was unheard of is now a “must do”. Now you have to check runout and all kinds of needless procedures that cost $$$$ where there was no need before.

Now to er on the side of caution, when in doubt …swap it out.

Which are unheard of in a properly maintained system that gets a routine relining and bleeding (on average) every two years. Most people need brakes every other annual safety inspection. Some, every year.

I wouldn’t say that…With my 4runner…YES…About every other year I end up replacing the brakes…But with my wife’s cars…Fronts every 4-5 years…and the rears…every 6-10 years. She averages about 25k/year…And most of her driving is back roads to work. I just inspected the brakes on her 07 Lexus with 76k miles and they look fine…easily another 25k miles left on them.

When I replace the brakes…I always bleed them…And about every 3 years I’ll completely replace the fluid…and it’s usually very dirty…Comes out a very very dark brown or black. IMO…it’s well worth it.

And that right there is the reason why after so many years, you have to start replacing seized calipers, damaged master cylinders, and crapped out ABS modulators.

The brake system on a car is arguably the most important system on it.
Having brakes that work perfectly should be everyone’s priority, but there are so many cars out there where this task has been neglected, if not completely ignored.

Brake calipers are exposed to rain, snow, salt, oil spray, road grime, mud, brake dust, and who knows what else during the life of the brake pads. All this stuff gets onto the exposed part of the caliper piston, and gets caked on, and pulled into the caliper, and mixed with the brake fluid every time the brake pedal is released.

Between the outer and inner seals on the brake caliper is going to be a big build up of crud, which gets into the brake circuit. This debris can them damage expensive parts, and lead to partial or complete brake failure, eventually.

Flushing the system introduces new fluid at the master cylinder, and pushes all the old fluid and debris out of the calipers, and away from the expensive components. You wind up with a much better brake pedal feel, and safer brakes.

People need to change their thinking on brakes.
Their lives may depend on it one day.
The lives of the other on the road with them depend on them EVERY day.

BC.

If the master cylinder is emptied(turkey baster) and refilled with fresh DOT 3 at every oil change and while the oil is being changed the bleeders are opened and the fluid allowed to drip, the fluid will remain clear and hydraulic failures will be minimal. Or so it seems after many years and hundreds of fleet vehicles and many millions of miles.