Should be able to apply vacuum at the vacuum ball reservoir line and
9000 feet isn't going to help but unless the system has leaks it should
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.
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
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
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
New foam and it was hushed right up.
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!)
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.
This rig had been last worked on by someone that should not be in the same
universe as anything remotely resembling a substitute for an empty toolbox.
Timing was 4 degrees slow, the 4MV quadrajet had bent step-up rods and
linkage to the step-up piston, misadjusted (too tight!) airalve, float too
low, fuel filter in backwards and was loose on the manifold (it shifted
around when I loosened the fuel line).
It was running hot, had bad vacuum lines (distributor advance vacuum line
was burnt!) and was in a general mess. Gas mileage was non-existant (10
gallons to go 25 miles).
We measured fuel line temps at 160 - 175 degrees between pump and carb,
fuel pump at 155 when it waqs vapor locked. That gives an idea of under hood
temps it had and that was the heat I think has damaged the vacuum lines.
(which has been drained at some time in the past) and I'm trying
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
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