Ok,
I am trying to clean up my engine bay, it is completely stock 70 duster with a 225. The car has a/c and automatic transmission. Anyway, in line with the heater hose is a small piece pictured below. It has a vacuum line running to it. I want to replace the heater hoses, can i remove this piece, i have no idea what it even does.

I think it's the heat control valve, controlling the hot water flow.

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Part of Tyrde-Browne Racing

is it necessary? I have had other slants without it. The heat works perfect on the car so i dont want to mess it up, but the piece is really rusty and looks terrible. If it is something i can remove, i would like to do it.

If you remove it coolant will flow through the heater core full time. At the best it will defeat the AC and at the worst you'll have full heat, full time. That valve belongs right where it is.

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Joshua

That is the hot water control valve, for the heater/ac. In heat mode, or any A/C mode except max cooling/recirculate, there is no vacumm applied to the valve, and water flows through it to allow heat, or warming of the A/C air. In max cooling, vacuum is applied to the valve, and shuts off the hot water, to allow additional A/C cooling. If the valve is removed, there will be hot water flowing through the heater all the time, and even though you will have A/C it will not be as cool as it could be, I suggest you replace the valve with a new one, as the old one is most likely not working properly, anyway.

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Charrlie_S
65 Valiant 100 2dr post 170 turbo
66 Valiant Signet 170 nitrous
64 Valiant Signet
64 Valiant 4dr 170
64 Valiant 4dr 225

that answers that, thanks for the info. I had never seen this valve before, but i have never had an a/c car before either.

Pull it off, sand it down, paint it, and put it back in place. Then it won't be ugly and you will still have cold A/C.

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Test first to see if it works. Apply/release vacuum to dashpot and see if the link between the dashpot and the valve moves. If not, it's bad.

If you decide to remove the valve (long term) remember to plug the vacuum line.

The heater control valve was non-op in my 73 model. I was not able to find one that looked remotely like the original. Ended up using a generic vacuum controlled valve and fabricating a mount so it could be used in the original location. If you have to go this way, make sure you know how the valve is supposed to flow. It matters.

If someone out there knows of a direct replacement for this valve, speak up. I'd like to know what it is. Probably redfivexw would like to know, too. Thanks.

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You can't fix stupid. - Ron White

what he said

hi charlie- remember seeing this valve on ac equipped swingers in the early 70s and figured it was exactly what you explained. however non ac equipped a bodies did not have it.does that mean they had constant hot water flow through the heater core? that would seem counterproductive on a hot day when you want some blower venting. also if i understand your explanation correctly, why would you want warmed air from the heater core to go to the ac when the ac (normal) is on? seems when you want the ac on you wouldnt want air warmed by the heater core to operate. afraid im missing a point here. thanks bob f

Non A/C cars did not have the valve. The purpose of the valve is two fold.
1) Shuts off hot water to the heater core, when maximum a/c cooling is desired.
2) Allows hot water to the heater core, for heating, or modulating the temp of the air conditioned air. If there were no hot water in the heater core, the a/c discharge air would be max cold. The air is cooled by the evaporator core, to approx 40 degrees, then the air is bypased around the heater core. If you move the temp lever towards "warmer" not all the air is bypased, some goes through the heater core, and is reheated, then blended with the cold air to achieve the desired outlet temp. If the hot water is off, there will be no reheat (read temp control). If there is hot water all the time, there will be some radiant heat, and also some reheat, due to air leakage, around the air door. When testing the valve, test for water flow, as well as movement of the link. Even if the like moves the seal inside the valve could be bad, and allow water to flow. Also check to make sure the valve doesn't leak water where the lever goes into the valve.

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Charrlie_S
65 Valiant 100 2dr post 170 turbo
66 Valiant Signet 170 nitrous
64 Valiant Signet
64 Valiant 4dr 170
64 Valiant 4dr 225