Recently got winched out in snow and had no pedal pressure even after new master cylinder install and bled still pissed. What happens or how can u tell when your power booster assist for brakes thing is broke??

check your vacumn line on your booster it may have pin hole in it. It also has a "check valve" to keep pressure up in the booster....it might be bad. You might still have air in lines......did you replace the seal in the MC/booster? ....