Are these the heater core lines?

Richard L · Post by **Richard L** » 18 Sep 2006, 10:00

I am getting ready to replace the heater core in my '86 740 GLE Wagon. The Haynes manual refers to clamping off the lines to the heater core. But I see two metal lines going from the radiator to the firewall. How do you clamp off metal lines? They aren't transmission cooling lines are they? These are the only lines I see coming from the radiator to the firewall.

Post by **billofdurham** » 18 Sep 2006, 11:59

But I see two metal lines going from the radiator to the firewall.

The heater pipes are rubber and do not originate at the radiator. Depending on the engine the inlet pipe will come from near the rear of the block and the outlet pipe will go into the engine towards the front of the block. Both pipes will be connected to the stub pipes of the matrix at the firewall. If memory serves me correctly they are one above the other.

Bill.

Richard L · Post by **Richard L** » 19 Sep 2006, 20:46

Thanks Bill. This makes sense, as the coolant will be hotter coming from the engine. I'll look a bit deeper and try to locate them. I was going to try to loop the the connection back while I work on getting to the heater core from inside the cabin.

Richard L · Post by **Richard L** » 25 Sep 2006, 18:23

I found that 1/2" copper pipe works nicely to reroute the coolant back to the engine while working on replacing the heater core from inside the cabin. I made a U shaped pipe that mimicks how the heater core pipes come through the firewall, but found that the hoses are flexible enough that I could have used a straight piece of pipe and it probably would have worked just fine for the short period of time that I will be working on the car and needing to drive it as well.