Rotting heater control valve? Risk?

Maintenance advice to keep your Spider in shape.
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essenz
Posts: 19
Joined: Wed Jan 11, 2023 11:46 am
Your car is a: 1984 Pininfarina Azzurra

Rotting heater control valve? Risk?

Post by essenz »

Not sure if this is a dumb question but... while fixing the passenger speaker wiring, I took a glance at the heater control valve. It is severly corroded, in fact its missing the top half where the cable connects to divert flow.

I assume this is a MAJOR risk for leaking inside the cabin, right? I have no idea how this thing isnt leaking right now to be honest.

I imagine a thin layer of rubber (thats old and dry) is all thats left holding the fluid in and not leaking. My plan was quickly grab some 5/8" ID heater hose, drain the system down, and bypass the heater core all together in the engine bay.

Thoughts?

Here is a pic: http://www.essenz.com/valve.jpg
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18Fiatsandcounting
Posts: 3798
Joined: Fri Mar 15, 2019 11:23 pm
Your car is a: 1969 and 1971 124 spiders
Location: San Francisco Bay Area

Re: Rotting heater control valve? Risk?

Post by 18Fiatsandcounting »

essenz wrote:My plan was quickly grab some 5/8" ID heater hose, drain the system down, and bypass the heater core all together in the engine bay.

Thoughts?
Yikes! Given the state of your valve, I think this is a good course of action. Corrosion and solidified coolant may be all that is keeping your valve from leaking. In time, you might want to replace the heater core and valve and remove the bypass hose in the engine compartment.

-Bryan
essenz
Posts: 19
Joined: Wed Jan 11, 2023 11:46 am
Your car is a: 1984 Pininfarina Azzurra

Re: Rotting heater control valve? Risk?

Post by essenz »

Yep, just bypassed it this morning with a 5/8" barb splice, then vacuumed out what was left in the heater core.

Eventually I'll replace the heater control valve, but for now its not a priority considering my heater in general doesn't work (something electrical with the fan not turning on).

It was a good opportunity to flush the flush old coolant too. Wasn't that dirty, but the concentration seemed a bit glycol heavy to the eye, so now I have a clean 50/50 in there.

Just got her up to temp, cooling down now and will bleed out any air for the bleeder T in an hour, then take a nice 50 deg Sunday cruise.

I'm really glad I spotted this while fixing the speaker wire. I recently got this car, and it was in very very good shape, but after a week of close inspection I have found several small things like rubbed/frayed wire on the Lamda sensor (fixed), cracked/slipped off vacuum hose on the fuel pressure regulator, additional frayed wires during the speaker fix.
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