Please help, earlier this morning while driving from work, an young man was driving crazy on the freeway. He spin out of control hit 2 cars, then hit the semi-truck in front of me. Mind you we are all doing 70mph. I had to slam down on my brakes to stop. Now my brake symbol is on 🅿❕and my brakes are to the floor. Please give me an idea on what may be the problem. I replace my brakes, rotors all around last summer. Please help. Thank you!
It sounds like you either blew a brake line or possibly a seal on one of your calipers. Regardless, you should NOT drive the car. Have it towed to a reputable service station and have it inspected and fixed. A blown brake line may be inexpensive (a lot of the cost is the labor involved to re-route it through the chassis), a blown caliper seal may require a new (or rebuilt) caliper.
@JohnDream has it right, his picture may help to amplify his answer.
As he said this is a closed system with the brake fluid reservoir providing for some small losses, expansion and contracting from temperature, etc. But if the pedal is on the floor, it's very likely there is little to no fluid in the system, or an extreme amount of air.
Just be glad this is all you have to deal with. Sounds like a very scary near miss.
The brake symbol usually comes on when the level of fluid in the master cylinder is below a certain level. Usually from a leak.
Your brake system works on hydraulic pressure via brake fluid. When you depress the brake pedal you are increasing the brake pressure through a system of lines and hoses which go to your calipers. The calipers squeeze the brake pads against your rotors slowing the car. It is a relatively simple system and a closed system.
A closed system means that no fluid is lost unless there is a leak. When a leak occurs fluid could seep out of several places, generally including the master cylinder, brake lines, brake hoses, or your calipers. When fluid is able to escape air takes its place, so almost certainly you have air in the lines.
The reason the brake pedal will go to the floor with air in the lines, is that air is much less dense than the brake fluid and compresses much easier, which leaves your car with reduced (or nonexistent) braking ability which is very unsafe and should not be driven, because you will continue to lose pressure until this is fixed.
If you plan on fixing it yourself you will need to find the leak, which can be done by examining the places mentioned above and look for brake fluid in any of those places. Try pumping the brakes rapidly and checking around and under your, tracing the lines starting at the master cylinder all the way to the calipers. Look for puddles or drips of brake fluid under the car in these areas.
Once the issue is found you will need to replace the part which has failed (obviously), which requires draining your brake fluid and removing the air from the lines by a process known as bleeding the brakes.
A similar situation happened to me recently where I just barely dodged an accident but had to lock up the brakes, shortly there after I had the same problem because my brake hose had failed due to the stress put on it.
Your brake system has low fluid from a leak, find the source of the leak and bleed your brakes or get it towed to a shop and have them fix it.