Yes, have to fireseal around pipe on both sides of firewall.
The evaporator drain tube through the firewall is pluggged.The evaporator drain tube through the firewall is pluggged.
no, for health reasions,
The separation between the engine compartment, and you, is called the firewall. The Steering shaft, from your steering wheel runs through the firewall, the heater hoses run through the firewall, the power brake vacuum unit is connected to the firewall, your ignition wires etc run through the firewall.
1 unit vertically down for each 12 units lateral.
looking under the firewall, follow the hoses and wires that go through the firewall. One will have enough room to squeeze the wires through. Make sure that you can reach the wires on the other side of the firewall as well.
No, only when water is run into it.
There is a drain tube that goes through the firewall and comes out under the car. Use a piece of wire to stick up there and unclog it, water will run out when you have got it.
Cut into the existing drain where you feel it would help the most and run a vet to the outside, preferably to above the roof line. At the point furthest from the main drain.
Either the heater core is bad or one of the pipes going into it has come out of the core. The drain in the firewall is for condensation from the AC which is in the same box. Temporary fix is to connect the two heater hoses that go through the firewall together bypassing the heater core. You won't have any heat, but that should stop the over heating of the engine.
Run a snake through it. Drain cleaner might work, but I wouldn't promise it.
Copper plumbing has a protective layer on it to prevent the water from actually touching it. The control of the water is run through valves that move around joints which are also known as elbows to circulate through the home.
Not necessarily. 1/4 inch per foot is good enough. You just want it run away not create a waterfall.