I replaced all 4 brake calipers on my truck maybe 3 months ago. Since I've had the truck my abs and brake light are stuck on. Tonight I started my truck was driving home and as soon as I pulled out of my work parking lot to push my brakes and they wouldnt go down much it was just clunking in the pedal? Parking brake isn't stuck on and I have plenty brake fluid trucks never done it before but all of a sudden?? I pumped the brakes once it happened and boom back to normal but now I'm not trusting my brake system any ideas??? FAST! Lol

 

When you put calipers on, did you spread the calipers by not cracking the bleeder? you may have pumped fluid back into the ABS unit and may have caused it to fail.. just a guess..