Brake Fluid

OK...so I checked my brake fluid level in the little reservoir thing with the black lid. I think it's low...if I take off the lid...I dont see any liquid. So maybe I should just go ahead and change it out. How do I do that? Where do I drain it out of? What kind should I put back in...and where do I put it in at?
And if it's low...what effect does that have on braking...will you have to puch the brake in further to get it to do something? Also, how much? Thanks.

What year, make and model, disc or drum brakes on the rear, and is it equipped with ABS brakes? The questions you have asked, have different answers for different vehicles.

What year, make and model, disc or drum brakes on the rear, and is it equipped with ABS brakes? The questions you have asked, have different answers for different vehicles.
It's a 1996 Chevy S-10 Blazer 4.3 The front brakes are disk brakes and back are drum. Yes i believe it's equipped with anti-lock brakes. Sorry...I'm dumb

OK...so I checked my brake fluid level in the little reservoir thing with the black lid. I think it's low...if I take off the lid...I dont see any liquid. So maybe I should just go ahead and change it out. How do I do that? Where do I drain it out of? What kind should I put back in...and where do I put it in at?
And if it's low...what effect does that have on braking...will you have to puch the brake in further to get it to do something? Also, how much? Thanks.

If the hydraulic system reservoir fluid level is so low that air is introduced into the master cylinder when pushing on the brake pedal, the result will be a spongy pedal. If too much air is introduced, there will be no resistance when pushing on the brake pedal, and there will be no braking ability, (no brakes). In either case, the hydraulic system must be bled according to the specified procedure.

If the fluid level is low, that may, or may not indicate that there is a leak in the hydraulic system. When the pads are new, the caliper pistons are retracted in the caliper bores, and the reservoir is then filled. As the pads wear during their life, the caliper pistons extend outward as they self adjust, and the fluid level in the reservoir drops as a result. When a brake job is performed, and at regular intervals during the life of the brakes, the hydraulic system should be inspected for leaks and repaired if present. There is a "max" line on the side of the reservoir; it should be filled to that line with DOT 3 brake fluid available at any auto parts store.

To "change out" or "flush" the hydraulic system requires a procedure that differs greatly with or without ABS. You need to be certain which system you have. Each unique system procedure must be followed according to the service manual, also available at most auto parts stores. Hope this helps.

NOTE: If during the life of the brakes, fluid is added and there are no leaks; when the caliper pistons are retracted for new pad replacement, the fluid that was added will be forced out of the master cylinder making a mess under the hood, (brake fluid eats paint very rapidly).

Would appear that you need to look at all your brakes right now. If the fluid is that low either a leak or your pads and shoes are so low that the calipers and wheel cylinders contain all thats left. I would suspect the rear wheel cylinders had a leak and you should see them leaking down the rear side of the tires but take those brakes off now and inspect.