95 Lumina rear brakes/low pedal.

limited info generic answer were the drums turned --most likely glazed over -shoe cam worn --or adjustment needed ---

Once you have bled the air from the brake lines,clamp off the front brake hoses carefully.Does the pedal feel better now?
Then the pad /caliper fit is allowing too much play.Is the pedal the same?Then clamp the rear hose and try the pedal.Is it fine with the rear hose clamped?If so we now know the problem is at the rear brakes.One common low pedal rear brake cause is brake shoes that do not fit the drums.Remove the drums and look at the shoes,are they showing contact wear fully or just in the middle of the shoe?Remove a shoe and place it in the drum.Can you rock the shoe against the drum surface?Once drums have been resurfaced,the shoes will not fit fully against the drum allowing the shoe the flex when applying pressure to it and this can easily create a low soft brake pedal. Of course rear brake adjustment must be correct once brake shoe contact is correct.To correct brake shoe contact,have your shoes re arc-ed to fit resurfaced drums or install new drums.Don't overlook brake master cyl /brake pedal push rod adjustment too.

if its in the rear it usually means either too much brake dust in the drums or a leaking wheel cylinder.if its front brakes then you have a bad flex hose or pinched brake line.hope this is what you needed please rate this answer.

Yes, you can adjust them by removing the small oval plug on the back of the back plate on the brake assembly. However you need a brake adjusting tool, you can use a screwdriver in a pinch if the angle is right. It sounds like there was nothing wrong with the brakelines or fluid so there shouldn't have been any reason to bleed the lines. It sounds like there might be air in the brake lines. You might want to make sure they are bled properly, have someone help you by pumping the pedal and holding it while you loosen the bleeder, when the pedal is all the way down make sure it is held down till the bleeder is retighted. repeat this till you get a steady stream without any air bubbles. Never let the pedal move up while the bleeder is loose, this will **** air into the system. Make sure to inspect all of the brake lines for leaks. Don't overtighten the brakes, this will cause the shoes to overheat and crack. Don't short this fix, if you are unsure find someone who has experience to help.

Is the problem your brake pedal is to low There is an adjustment for the brake light switch at the top of the pedal that could affect pedal hight slightly But if down a 1/2 inch or so i would suspect some kind of a problem with the brake system it self how well do the brakes stop the vehicleand have you noticed more of a drop in the pedal over time?

Tricky and risky ,and if garage is not to far away, use the parking brake and brake pedal at low speeds to stop. Taking out of gear at stops at a light or crossing/stop sign. Otherwise, cap and plug the main line at rear axle brake tee spliter from front.

your power brake booster is blown out
the seal has a leak in it
run the truck for 3 minutes and shut it off. with the windows up listen carefully while you gently apply the brakes
listen for a hissing sound of air leaking.
the sound of these leaking is a very soft sound

put another caliper on that side, i am seeing this defect more and more often,, should be no question for warranty replacement

You may have a bad brake Booster and it could have brake fluid in it.
Also you may want to try a complete brake fluid flush.

are your rear drums set up? why did you bleed the brakes. when only when you installed new pads?