The best advice is to follow the manufacturer's service interval recommendations. Fluid should also be changed if it appears dirty (new fluid is nice clear yellow) or the cap has been loose on the reservoir (as brake fluid is hygroscopic and will absorb moisture from the air, rendering it ineffective). Find a mechanic you trust and follow their recommendations.
Every 2 years
You should check your brake fluid every three months to make sure the levels are okay. If the levels are down, replace the fluids immediately...better safe than sorry.
PS should be 18000 miles and brake fluid about 30000 miles PS should be 18000 miles and brake fluid about 30000 miles
It depends on the type of fluid and level of contamination or heat. if there is no problem with the fluid it should be left alone!
Rear calibers or wheel cylinders are sticking. This is most often due to brake fluid that is contaminated with moisture. This moisture will cause internal parts to rust. Replace the rear calibers/wheel cylinders and replace the brake fluid with fresh fluid from an unopened can. It can also be a defective proportioning valve.
once a year
Usually it's low brake fluid or a problem with the abs. Check the brake fluid reservoir. Often the brake fluid will go down as the brake pads wear and the calipers has to travel further.
If, as you say, it needs doing then it should be done as soon as possible. Brake fluid seldom needs changing though it does degenerate over time, mainly by absorbing moisture. The precise detail will be in your manual. The fluid reservoir needs checking topping up occasionally and certainly will require it after a brake pad change.
brake fluid changes and brake inspections should be done atleast every two years, mainly the brake fluid has a tendancy to soak up moisture in the air and then this accumulated water tends to boil in the lines and calipers and brake cylinders during use, causing air pockets and a degradtion of braking, and can cause a complete loss of brakes at times.
Most car makers recommend that the brake fluid be changed every two years. The make/model of the vehicle is not an issue, it is just that brake fluid has a "life span" of about 2 years once it is in use. Brake fluid is "hygroscopic", which means it absorbs water from the air, so after about two years of use it needs changing.
The reservoir for each of these is usually transparent, so you can also verify the condition of the fluid at the same time. The brake fluid should be an amber color, while transmission fluid should be red. If you have an older car, you would check the brake fluid at the master cylinder, each side of which should be full. Be sure to close the lid securely after checking the fluid. The transmission fluid (on automatic transmition) is checked via a long dipstick, it should read between "add" and "safe". If you are in need of more transmission fluid, pour it in down the dipstick tube. A long funnel works well for this. Be sure to use the appropriate fluid for your transmission, they aren't all created equally. Or about 3,000 miles(about 3 months)
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