I have question for add brake fluid, are there any techniques to add on the brake fluid? Or just open the cap and pour it in? I searched online, they told do not shake the break fluid before pour in to vehicle because the air bubbles…etc. and discard unused or old break fluid. Thank you
its simple as just putting in the brake fluid... not sure how the bubble would reach the brake lines if you already have fluids in the reservoir...
You haven't mentioned why you're thinking of adding brake fluid. Do you have a leak, or have you done work on the brakes that caused fluid loss? The brake reservoir has a min and max line. The only time you should ever see the fluid near the max line is when (a) brand new pads have been put on at all 4 wheels, and (b) the brakes have been pumped with electric power off until hard, so all the fluid from the pressure accumulator is back in the reservoir. Any other time, the fluid level should not be at max. As soon as the booster pump wakes up it uses some of the fluid to fill the accumulator, and as pads wear, more fluid goes to the calipers. If you add fluid under those conditions, you will have too much. If it is comfortably above min and you're not losing any, you're good. If you're losing any, you need to fix the leak, not just add fluid. -Chap
^ what he said. Unless you've got a leak, no reason to add fluid. Level will drop as pads wear, and likely return to top mark with install of new pads.