can you block the high side on the ac on a car to stop a leak
freeze plug has blown out or leaking
the heater core, heater core hoses or heater control valve is leaking
No, unless it is a very low mileage car and the reason is a leaking top seal. If one shock is leaking in a high mileage car, it means the other shock will also be worn, even if its seal has not leaked. If you replace only one, the damping will be unbalanced from side to side. This is potentially unsafe.
YES. Good possibility if it is leaking at the passenger side
The overflow tank is either cracked or its overheating and leaking from the cap
are you sure its the case and not 1 of the hoses ?
No It would not unless beside that plenum on your block is a crack in your heads and your leaking coolant or even leaking internally check head gaskets
Leaking from the water pump at the back on the passenger side.
Sounds like heater core is leaking
ON THE PASSENGER SIDE OF THE BLOCK
on the frame or on the side of the engine block
Pentosin G12 coolant is pink. If it's leaking inside the car, that sounds like a heater core problem. If it's leaking on the ground, the passenger side is where the hoses and water pump are.