I have a 2002 Kia Spectra and when you step on the brake sometime you have to pump them up for it to stop. But while you have your feet on the pedal it slowly goes down to the floor. What is causing this
Your master brake cylinder is probably leaking. Get this fixed ASAP
You’re describing a brake master cylinder that’s leaking internally.
When the cup seals become worn inside the master cylinder it allows the brake fluid to bypass them. When the brake pedal is pumped it causes the cup seals to expand and the hydraulic pressure is restored. When sitting at a stop, and the brake pedal slowly sinks to the floor, that’s the brake fluid bypassing the cup seals inside the master cylinder.
Have the brake master cylinder replaced and it’ll restore a firm/steady brake pedal.
Get this done right now. I am not saying it will fail today, but it is possible. I am writing from experience.
And when it does fail, it’s not going to give you a whole lot of warning, beyond what it’s telling you now.
Yes, classic symptoms of a worn master cylinder. Get it fixed ASAP!!!