When i drive my 99 silverado z71 5.3, it feels like the front brakes are not working. I can feel the rear brakes applying and it feels like they are the only thing stopping my truck. I have not done any work to my brakes so i dont htink it is air in the lines, and the pads are not too low, but they could be changed. My ABS lite and parking brake light are on, but they came on last year and i havent made the time to check the codes. But its a year later and just now are the brakes giving me problems. Any ideas on what to check until i can get the codes read?

Thanks