Hello,
Today, I discovered that the brake fluid level was low. It was just three months ago that I topped up the brake fluid.

Previously, I didn't top up brake fluid for years. So I'm suspecting a leak somewhere. \

1. How can I confirm whether there's a leak?
2. How can I determine the location of the leak?
3. How can I fix the leak?

 

Finding a leak is time consuming,. but its all visual. Look at all the lines, remove the calipers and check the pucks for leakage, look at the master cylinder and under it to see if its leaking. It has to be going somewhere and it will be obvious. Just have to remove the wheels and calipers. But first really look at the lines

 

Have you checked the brake pads? When the fluid is low, normally that means it's time to replace the pads.
If that,s not the issue, the fluid will leave a trail where it is leaking from. Pull the tires as the caliper is the first place to look.