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!

[Lycoming-8]

Thankfully that was one job I never needed to do on our W115, as it appears that the car was assembled around that and the HVAC fans on this model. There has beeen some discussion about this in the past, but more often it was the fan access. As far as the stop leak product, there is no way to prevent water and/or product from moving out of the heater section and into the general engine cooling system!!

[taygan]

So I've looked at the hoses, and hopefully I can disconnect JUST the passenger side core.

BUT, there is only one return hose coming out of the firewall. Hmm.. 2 going in, one on the driver's side, one on the passenger side. Only ONE out that I can figure out, on the passenger side.

Does anyone know what the heater core looks like INSIDE, and what the hose routing is?

The manual has a diagram, but I can't relate the rough diagram to actual hoses, as in, is it really one core with 2 parts, or is there a hose inside that I can't see that might be an "easy" fix.

Can I disconnect just one side, or do I need to disconnect my heat for the rest of the winter? (only -7F this morning, ahh mid-March in Alaska).

THANKS!

[Stevo]

I can only relate what I heard a mechanic say about that job "next time I would cut it out through the fire wall"