I attended a BMW brake clinic, and the guy there said yearly. While that may be a good practice, most people never change it and never see a problem.
The issue with brake fluid is that it absorbs moisture. When this moisture laden fluid is in the caliper, the heat generated can cause it to boil. Most people don't use there brakes that hard, but if you drive in the hills or tow something, this situation can come into play.
Every other time I change my brake pads, I suck as much out of the fluid tank as possible with a turkey baster, then refill and bleed the heck out of them to get rid of the old fluid in the lines, then top off with more new fluid.
I also use the baster to drain the power steering reservoir so it can be refilled with fresh fluid every couple of years.How often does brake fluid need to be changed?
Any time the break fluid becomes contaminated or discolored (Dis-colorization is a sign of contamination) they have really good devices now that allows a shop to attach a power bleed system to your car. they put in about a a half gallon of fluid and attach it to the master cylinder. they then attach an air hose to it, go to each wheel and open then bleed valve. they watch the fluid until it come out clear. lock it down and move to the next. this cleans all the old contaminated fluid out of the system. best way to bleed and flush breaks. I use this device often on the classic cars I work on. takes about 15 minutes to do all 4 wheels. Works on slave cylinders as well. Most shops will charge around 60 to 70 to do the whole job.How often does brake fluid need to be changed?
Most car manufacturers don't require it unless a master or slave (wheel) cylinder have been replaced.
But it is inexpensive insurance and an excellent preventative maintenance item to replace the brake fluid whenever you have your brake pads replaced.
Standard brake fluid (non-silcone based) is hydroscopic (absorbs water), so that it can develop rust particles in any steel parts in the brake system, which can abrade rubber seals in the brake cylinders, causing them to leak or fail. And, under hard braking conditions, water in brake fluid can boil and you could lose braking effectiveness.
By changing the fluid at every brake pad replacement, you eliminate this problem, as well help to flush out any contaminants in your brake lines.How often does brake fluid need to be changed?
If you have ABS brakes which are standard on most new vehicles now, the fluid needs to changed every 18 months or 20,000 miles.
Brake fluid absorbs moisture and moistures creates two major problems in any brake system.
First, it corrodes precise metal hydraulic components such as valves and pistons and causes them to stick. Eventually, moisture also creates a rusty sludge inside the system that clogs its vital valves and ports.
Second, moisture can degrade brake performance by causing vapor lock inside the hydraulic system. New brake fluid has a boiling point of 425 degrees Fahrenheit. After only 18 months in
service, brake fluid can absorb enough moisture to lower its boling point to 300 degrees. If the fluid boils, vapor bubbles occur. When this happens, the brake pedal will feel mushy or spongy and it will take more pedal effort to stop the vehicle.
Routine brake fluid changes are necessary to keep the intricate hydraulics inside anti-lock brake systems (ABS) performimg properly.How often does brake fluid need to be changed?
EVERY TIME YOU GET THE BRAKES REPLACEDHow often does brake fluid need to be changed?
When ever it becomes contaminated, or in most cases when the master cylinder is replaced.How often does brake fluid need to be changed?
you should never have to change your brake fluid, unless it is or gets contaminated with a foreign substance, IE water, dirt etc.
If your master cylinder fluid is getting low and if you don't have a fluid leak, that is a sign that your pads or shoes need to be replaced
