driving me nuts!
hi first time poster here. today i replaced the master cylinder, reservoir, combo valve, and one brake line that was shot to stop a crazy brake fluid leak. i got everything in after a while and bled the front brakes but i'm getting nothing. everything is fine with the truck off but when i fire it up the pedal goes straight to the floor and doesn't apply the brakes at all. it's an 85 s-10 2.8 non-abs. if i pump them quickly with the truck on i start to get some pressure and some braking but it dies off if i let it sit for a few seconds. any ideas what this might be? i bled the brakes twice and i couldn't find any leaks so im getting frustrated. is there maybe a vacuum connection i'm looking over or something? please help, thanks, dennis