Heater/A.C. question

How many miles on it?

JAM

Unknown ... odometer broken but speedometer works.

Estimate based on wear and tear, over 100,000 miles.

I don't understand why you need the info on mileage. All I need is where the vacuum is sourced for the HVAC so I can maunally pump it and listen for doors operating or not.

Budd

(which has been drained at some time in the past) and I'm trying

Budd

From a port on the intake manifold behind the carburetor, usually. At least all the Chrysler product of that era that I have owned. You might still have the Emission diagram under the hood that will include this information!

Bob AZ

It may be that you have insufficient vacuum because the motor is worn out. If you do not find any leak this may be the problem.

JAM

JAM

Cool. How fast can it go?

It's the altitude. The vehicle meeds to be returned to sea level.

Should be able to apply vacuum at the vacuum ball reservoir line and listen inside.

9000 feet isn't going to help but unless the system has leaks it should work fine.

My first suspect would be the o-rings in the control head itself. The one between the ports and the actual selector valve. You can do a simple repair if they are just worn. You take the FIXED side of the valve and a FLAT chunk of glass or granite and some fine sandpaper and remove enough so the rings seat again.

Think diapraghms, not motors.

Mileage has little to do with diapraghm longevity, but times cycled and heat do.

And that is why I wanted to listen for leaks.

Budd

You're not a mechanic, are you?

Budd

I'll check it out but the control head is probably plastic, not metal and heavily greased.

Budd

Thanks, Bob. This is what I wasn't sure about as many vehicles source the vacuum off other lines.

Budd

Yes, FAA Certificated.

Doesn't say much for "FAA Certified" mechanics, does it? BTW, what is "Certificated" anyway?

Budd, about 90% of the time, I find these problems to be split hoses, and split rubber couplers where nylon hose is used. I'd do a very careful check of those hoses, as I've found some vehicles have nylon hoses, with couplers in the middle somewhere (helps in the vehicle build stage so the assembly line can connect things up quickly) that have cracks because of aging.

Just fixed one (A VW, however) with exactly that problem the other day--vacuum leak, and no HVAC operation. Cracked nylon to HVAC unit coupler that I could not see, but it was bad. (Of course it was bad, I could not see it--bad parts are more likely when you can't see them!)

No dog in this fight but based on your comments I'm glade you're not working anywhere near my bird.

Yep and the O rings tend to flatten out and not seal against the plastic. Then they leak vacuum. The O rings also tend to shift and block passages.

The next area are the actuators and the plastic pieces that connect to the door cranks. They like to break off over time. Then it could be the door itself.

"Certificated" means the FAA has issued me a certificate. Hardware is Certified, people are Certificated. Get it?

Yeah, right.

My son was a Navy AMRAM and he was CERTIFIED to repair Navy and civilian craft.

Budd

Heater / defrost door seals can cause strange sounds ... I had a 65 Valiant that had a seal go bad and on high fan dogs in the neighbor hood started barking and I got a headache (I'm sensitive to high pitched sounds and dog whistles).

New foam and it was hushed right up.

Budd

And both types of lines are more likely to fail from heat than miles.

I've turned a wrench or two (small engine mechanic, heavy equipment mechanic and I work on my own vehicles) I just couldn't find a diagram for the HVAC routing in the Ramcharger.

Budd