No return in brake pedal

[BCbill]

hey guys, just purchased a 80 2wd Blazer to sit beside my 81 swb stepside and having a problem with the brake pedal not coming back after applying. The pedal can be returned so as it is not applied by simply lifting the pedal up by hand (or foot). The p/o had just installed a new master cylinder, wondering if it a simple case of the system not being bleed or am I looking at a push rod or booster problem. Thanks

[Boom]

This thread mentions a bad master cylinder will cause it. So if it's new I would bleed the system and see if that helps.
http://67-72chevytrucks.com/vboard/s...+return+spring