Brake pedal goes to the floor and check brake system light is on?

The red brake light on is an indicator for the brake fluid level. When the light is on it does not mean to just fill the system. It does mean that there is something wrong, but the light is triggered on from fluid level. So why is the fluid level low? It is important to find this out and not just fill the reservoir.

More than likely you have a leak in the system causing air to be in the lines. The air in the lines is why the pedal goes to the floor.

Here is a guide that will help:

https://www.2carpros.com/articles/brake-pedal-goes-to-the-floor

We need to first focus on finding any external leaks and repair those. Once those are repaired we need to bleed the brakes and retest. If it still goes to the floor the you most likely have an issue with the master cylinder.

https://www.2carpros.com/articles/how-to-bleed-or-flush-a-car-brake-system

Review this material and then let me know if you find any leaks. Thanks

my fluid level is at the max level. I see no leaks, but the light saying check brake system is on and the pedal is on the floor or spongy.

Okay. Do you have the ability to check your own codes? If so, let's pull the codes and see what is there. If there are no codes then I suspect the master cylinder has a internal failure. To check this you will need to cap each of the lines coming out of the master cylinder and then press the brake pedal. If it is still spongy or goes to the floor then it is the master cylinder as the rest of the system has been eliminated. If you have a hard pedal then there is a leak or air in the lines somewhere in the system after the master cylinder. However, due to the light being on, I doubt it is air in the lines.

https://www.2carpros.com/articles/checking-a-service-engine-soon-or-check-engine-light-on-or-flashing

Let me know if there are codes and we can go from there. Thanks

I don't have a way to check codes.but your explanation is very helpful. I'll try to trouble shoot the master cylinder.
The truck has sat for 2 months,but started up right away. It did not have a code or and brake light come on before.I will get back to you . Thank you

Sounds great. Let us know what you find or if you have questions as you work through this. Most parts stores can pull the code for you free of charge but I understand that may not be an option due to it not being safe to drive.

If this was sitting for a while it is most likely the master cylinder. More then likely the seals inside have cracked and are leaking.

Thanks for the update.

Thank you.