The other day I asked where to attach the chains so I could hoist the engine. As you can see I got the help I needed It's a mess and the picture is bad, but it’s gonna be a lot nicer with a little work.

Look at the arrow, what’s the thing that it's pointing towards on the fender? Some vacuum thing for the A/C? The A/C is gone, can I remove this as well, still want the heater to work of course.
Another thing, there was this tiny little hose on the intake manifold going into the firewall. Any suggestions on what that does?

_________________
1970 Plymouth Duster

That small hose is likely for the A/c controls in the dash.
That canister on the fender is a vacuum operated heater control valve. It's there to cut circulation to the heater core so the A/C doesn't have to work as hard when it's running. If you're ditching the A/C you don't need it. You can just run new heater hoses in place of it. Be sure to block off that vacuum line for the canister though.
In case you were wondering, a plain heater box won't fit in place of the A/C unit. The firewall is stamped differently. It's not impossible, just difficult.

-James

_________________

Thanks for the answer!

_________________
1970 Plymouth Duster

I'm having difficulty making out the detail on the item you are asking about. If the "cannister" on the fender has coolant hoses running to it, it is indeed the heater control valve. If on the other hand there are no coolant hoses, it something else.

There is a small black plastic cylinder that has a vacuum hose coming out of it and is usually mounted in this part of the car. It is a vacuum amplifier, according to the manuals, but I'd call it more of a vacuum acumulator. It's purpose is to even out the vacuum supply that operates the various doors inside the A/C unit. Neither the heater control valve nor the vacuum amplifier are present on non-A/C cars.

_________________
You can't fix stupid. - Ron White

It's very hard to see in your photo, but from the position my guess is that it's a heater control valve if you car has factory AC; if it has heater lines to it, that's what it is; if not, not. AC equipped Mopars usually also had a vacuum reservoir installed; I've not seen it on non-AC cars.

For both AC and non-AC from about '73-78??? there was often a vacuum amplifier used to run the EGR valve, but I've never seen one mounted on the fender.

The reservoir is just a can w/ a 1-way valve to help maintain vacuum for the climate controls, etc., while the amplifier was to run the EGR valve properly. It was usually a simple metal can about 4x4" or thereabouts and tucked away someplace; often under the battery.

The amplifier usually was mounted on the engine near the carb, made of plastic and metal sandwiched together with screws and was very roughly 5x1" if I remember correctly.. It had several lines going to it; a small one off the carb gave a weak venturi signal that was "amplified" using manifold vacuum and sent to the EGR valve.

My experience with mine was that I could never get it to run like it was design. JCWhitney at some time sold a gizmo to help fix that, but by the time I heard of it, it they'd discontinued it.

There was also a "Fuel Pacer" system that used a vacuum switch to run lights to remind you to keep the vacuum high - we had some fun with that (http://www.tidewatermoparclub.com/TECH/yeehaw4.pdf). The one I used was on the driver's side inner fender.

Also, there were some California-only devices for NOx reduction that mounted in that corner - the TMC '75 Duster had one there. They were designed to retard the spark under certain circumstances by controlling the vacuum signal to the distributor.
From the location, I think that's the most likely possibility if it has no heater hoses. The OSAC (?) valve (for the same purpose) was used for other states, but usually it was more on the firewall someplace and smaller.

There were some state mandated NOx refits done to earlier cars in California too - I don't know what they looked like and they don't appear in the service manuals I have, but I'm under the impression they were similar.

PS I'm told that certain rare emission devices now are very valuable for restorations.

Thanks again for the help!

The "thing" was connected to a hose that ran next to another hose from the firewall into the front of the engine. "The thing" also has a small hose connected that runs into the firewall.

_________________
1970 Plymouth Duster

Much better picture! It is clearly the heater control valve; on AC cars, you want to be able to turn off the hot water to the heater so it's not fighting the AC evaporator; most non-AC cars don't have it.

It may not appear the same as the manual because some of the aftermarket replacements look nothing like the factory, but still do the same job. My 1971 B-body's valve was a big round plastic cylinder with a metal top full of internal passages and I was unable to fix it when it cracked, but back then could still get a factory part.

Thanks again. The A/C is gone and wont be used. Is it ok to remove the heater control valve and just run the hose directly to the firewall instead?

_________________
1970 Plymouth Duster

It ought to be fine to just remove it, but it won't hurt to leave it in. I can't remember which way the vacuum works - it's hazy, but I seem to recall that vacuum cut off the flow to the heater. It ought to be easy to check.

Note that some valves used differently size hoses in/out, so check before you remove it.