Heat & A/C dashboard control: vacuum

[Gerald F. Chase]

My '85 TC has lost ability to control the various doors in the plenum chamber(s) which send the heated or cooled air to various places, like defrost, floor, or dashboard outlets. I believe that it's because said system has lost vacuum due to a set of broken plastic nubs which connect the vacuum lines to the control panel, thereby system vacuum being lost. Engine idle is affected only minimally. I hear no "hiss". What's worse is getting exhaust or exhaust-like air into the passenger compartment.... yet the exhaust system is, to use a bad pun, "sound". There is no typical exhaust system noise.

Anybody know where I can get the needed plastic part(s)?

[Gerald F. Chase]

A follow-up: Do Eighties Town Cars have more than one vacuum reservoir?

I've lost all vacuum-control for the heat & A/C... but the brakes work fine. The engine idle may be slightly affected, but not much. The other thing I'm wondering about is.. perhaps the brakes need a greater reserve of vacuum to operate properly.... versus opening & closing of heat/defrost & A/C plenum doors??

Most, if not all, of these 80s TCs have a coffee-can-sized metal vacuum reservoir on the left inner fender. The problem is that after they're 25 or 30 years old, they have rusted to the point of insufficient structural integrity to hold vacuum anymore. I can't find any of these.

My local junkie offered me a smaller, round, plastic vacuum reservoir from that vintage Lincoln. Will it be an acceptable substitute?

Finally, I find that without any vacuum, some part of the emission system leaks exhaust inside the engine compartment... and such enters the heating floor ducts... due to no vacuum to keep things functioning correctly. I don't want to throw the car away [esp. because the A/C still has plenty of R-12 inside!], but I'm "at a loss" for what to do now. Ideas?

[LithiumCobalt]

Gerald, the coffee can rusting out is a common problem on these. You can either try to reseal it if it's just a crack. If that doesn't work, have to look for one from a dry southern car or retrofit a different type altogether.

[Gerald F. Chase]

Nick, How relatively critical is the SIZE of a substitute vacuum reservoir? The "coffee cans" do rust, for sure. I have a small, round, plastic one from an '80s junker.... but surely the capacity for it must be barely a third of the metal ones.

[Gerald F. Chase]

Well, I had to junk my '85 TC.. 'cause the transmission died. The car had about 176K miles on it. Too bad it cocts so much to re-do a tranny.... The frustrating thing is that most everything on the car still worked... Including all power windows... and A/C that still ran COLD on R-12! Arrgh!!!

But I saved hard-to-get stuff. I would have saved more things.... but it's been awfully cold outside here lately!