1975 115 240D Leaking Heater Core

[taygan]

Well, I noticed a puddle under the old rustbucket today and figured out that there was a leak down the firewall from the passenger side heater core outlet. I topped off with coolant and drove 20 mins home. When I turned on the heat (slid the heat control from cold to hot) I heard a hissing sound from the passenger side. Checking at home there was a steady pulse from the plastic box down the inside of the firewall to the passenger foot area.

I am planning on disconnecting the passenger heater core, but I am in Alaska and it was -9F this morning..

I've looked in the engine and chassis manuals and searched online but haven't found the info for 115 heater cores, other than how they related to removing the a/c condenser (which I don't have). Maybe I'm looking in the wrong places.

No A/C.

How difficult is it to remove the core, I can't find anywhere that sells them so if I can get it out without too much trouble I will bring it to a raditor shop. If NOT, maybe bar's leaks? How would I use it jsut on the heater core so I don't plug up the radiator?

THANKS!