What problem was the trans having before they worked on it? How many miles were on the trans, do u know if the trans had ever been serviced before? Was it a full trans fluid flush or just the filter and a few quarts? Before a correct answer can be givin by anyone, this info is needed. For example if the trans has high mileage and has never been serviced they should of only changed the filter plus 4 5 quarts to fill it up, if they did a full trans flush under those conditions they ruined it
It is more than likely coming down your Cabin Air Filter into your HEATER BOX adn then onto the Floor.If it happens when it is Dry, then you have a hole in your Heater Core....
I am assuming you have vac assist brakes which uses a booster and vac from the engine. Sounds like the vac line between the booster and engine has ice or some foreign matter in it.
check for lose wire connection off wires on solinoid and battery solinoid is connected on stater motor normally on the side off engine at the back off engine