Waterpump, hoses coolant reservoir are possibilities
The coolant will normally leak into the oil or into the cylinder
a leak in a head gasket could cause coolant to go into only one cylinder.
If there really is no leak then it is likely a head gasket allowing coolant to leak into the cylinder and go out the exhaust as steam.
Could be a worn out waterpump.
Coolant leaking into any cylinder is a clear indication that the head gasket has blown.
If a vehicle is loosing coolant then there is a leak. If no leak is visible then the coolant could be leaking into the oil, or leaking into a cylinder and being blown out through the exhaust.
If a coolant leak were caused by brake work, I'd never have that person work on my brakes - ever. Just the brakes, I would think it highly unlikely that it would result in a coolant leak. If they were replacing the master cylinder, then I could see a possibility of someone inadvertently causing a coolant leak, but that would still even be a stretch.
If your going through coolant then you have an internal head gasket leak you smell coolant because its getting into cylinder and burning
You have a coolant leak.You have a coolant leak.
Fix the coolant leak.Chances are the water pump has a problem. They were known for having a leak and with no coolant you have no cooling.But you may have a coolant leak elsewhere also. Your cooling system will need to be checked out.
Leaking heater core
Suggest blown head gasket with coolant leaking into one cylinder. Check colour of oil. If emulsified (mucky brown) then definite leak. Also, remove HT leads one by one to identify whether all cylinders are firing. If one is not firing, remove spark plug, then remove all other HT leads and turn engine over. You may find that coolant shoots out of the cylinder, indicating leak into that cylinder.