Rep Power: 0

I have been getting a brake light on
and noticed a decreasing amount of
brake fluid.
No fluid anywhere on ground. Possible
leaking into or around brake booster?
Would that indicate a bad master cylinder?
THANKS

 
Rep Power: 517

Yes, possible.
If fluid got into the booster, it has to be a failed master cylinder.
But you need to prove it first.
Prove it before tossing parts at it.



A brake fluid leak can be quite slow, slow enough you might not actually see puddles. Check each caliper, hoses, connection points, rear drums/wheel cylinders for dampness and stains

 
Rep Power: 118

Are you sure the pads and shoes have not simply worn down enough to trigger the light?

Best free check I can offer is too start the car and keep your foot mashed hard on the brake pedal for full 10 minutes.

If the pedal ends ends up dropping to the floor you definately have a issue leak.

Test brakes right after by low speed stopping a few times to make sure you didn’t just get fluid everywhere.