I have a 95 Eldorado, I am experiencing a leak at the connection where it "t's" from the heater dore into a steel line behind the engine. I called my local Caddy dealer who quoted me the price to the two steel lines. However they wouldn not tell me the approximate price to replace the lines. Can you help me with that, or are these parts easily replaced at home. Can you give me any technical details on replacing them? What is the normal operating temperature of the Northstar engine?