Anytime the check engine light or brake light comes on you should have it checked for safety reasons.
possible warped brake rotors. have a reputable mechanic check them.
You can "eye-ball" the thickness of the brake pads by removing just the wheels but removing the pads completely for inspection is best. For safety sake, the disc brake rotors should also be measured for legal thickness. Your local auto parts store can help you with that.
Check fuses, check bulbs, check connections.
check wiring, check bulbs, check fuse, check brake light switch,
The brake pads are probably worn. If not repaired, then the metal backer of the brake pads can cut into and damage the brake rotors. Noise is a sign to check the brakes as soon as possible.
tachometer quit working - all else on the fuse works. where is the tach sender? Is it possible to check the tach and sender without removing the instrument cluster? where do I find the wiring diagram for the tach and sender? auto: MB300TE, 1991 GASOLINE
Your brake fluid is how the brake system converts mechanical force of your foot on the brake pedal, into hydraulic force that applies your brakes. Without fluid, your hydraulic brakes will not function.
Check if all jobs that needed to be done are completed. check all dimensions (if possible) and check the surface finishes on the job
Spongy brakes are usually an indication that there is air in the brake lines. It is also possible the brake fluid is low, so check that first.
Take off the brake caliper, and brake rotor, under the rotor is a parking brake shoe, that is probably wore down and needs replaces. I
The brake lights and the tail lights are separate circuits. Check the brake light fuse, then check the brake light bulbs, then check the brake light switch.