SharkSkin

I'm referring to the old-school round-tube condenser as shown in the pic below. On the trip home from SATL, with the afternoon sun beating down on us through the windshield, the AC was just not enough. Having a black on black car doesn't help, but still... I am thinking of retrofitting with the later-style flat-tube condenser, which ought to be a lot more efficient.

Is there anyone using R12 with this type condenser and getting freeze-yer-nutz AC? I get, at best, maybe 38° at the center vent at highway speed. In town it doesn't cut it. Heater valve closes, I have checked and the hoses to the heater core do not heat up until I shut the car down, which opens the valve.

Has anyone done this swap, and if so, care to share your observations about how much of a difference it made?

anonymousagain

Lemme check The Blue Car tonight Dave, since I don't recall if it looks like yours with the round tubes.

FWIW, we recharged at one of Bill's A/C workshops last year, after swapping out a good-used compressor, and it is still TOO cold on full ...you have to set the slider to about mid temp or you'll literally chill your right knuckle!!

Will let you know if it's the same condenser....

SharkSkin

Thanks, I appreciate it. I think that by '80 they were using the later condenser style, but we'll see.

anonymousagain

You're correct Dave, it's got the black "flat square" tube condenser in it, so '80 must have changed over from the round tube unit.

BTW - Picked it up a spare condenser when I bought the replacement compressor. From an '84 with dryer still mounted (holes taped over). If you decide to do the retrofit, you can have it for cheap if you want it.

SharkSkin

Hmmm... I was going to pick one up from the breaker in a few minutes. How cheap? Also, if I pick one up from these guys and it leaks, they'll swap it out gratis. Would you be willing to reverse the transaction if it leaks?

IcemanG17

Dave
Granted I have the newer style condenser...but it gets stupid cold really fast.....I've seen temp differentials of 50-60F....or as cold as 18 degrees on the main vent.....now that my recirc flap works....it gets silly cold in no time!

Are you sure your HVAC vacuum is tight, since even a slight leak will cause the heater valve to open....OR you could have an internally failing heater valve that causes a leak...so hot water would ne leaking into the heater core....like this one

PorKen

I was having trouble with the heater while the A/C was on. The heater vacuum solenoid mounting is a simple twist lock, so I just popped it loose, effectively closing the valve all the time, even though it's still attached. (My valve was installed with the pot pointing down.)

Nice and cold, now!

SharkSkin

Thanks for the input guys --

Brian, as I said in the original post, the valve is not the problem.

Ken, why not take that vac pot off? It's dead weight, affecting your acceleration!

IcemanG17

Dave
The leaky valve in the picture opened and closed like it supposed too....but the broken internal seal made it leak....so unless you pulled the valve and looked inside it....you can't be sure

Bill Ball

A bad heater valve will heat the ambient air too. So, driving around even w/o the AC on, the vents will be warmer than outside air. With a good valve the vent air will be the same temp as outside air. A valve can look perfectly good internally (no bad seal) and and seem to operate correctly but still not completely close off the water flow. Comparing the vent and ambient air temp will detect that (hand in front of vent then out the window).

SharkSkin

As I said in the original post, the hoses are not heating up. Checking under the cowl, where the hoses penetrate the firewall, the hoses are cool to the touch unless/until I shut down, which opens the valve. The problem is the AC simply doesn't get cold enough.

Bill, normally the air coming out the vents is colder than outside air(talking about w/o AC here) because the car is kept in a cool garage and the HVAC parts are cooler than ambient once I get the car outside. It remains so until I shut down and the heater valve opens(I have a fix in mind for that -- separate issue)

SharkSkin

Confirmed with IR gun, no heat getting past the heater valve.

Also, new data, temp drop across the condenser:

138°F at the inlet fitting to the condenser
112°F at the outlet fitting from the condenser.

Question: Anyone with either early or late condenser style getting more than a 26°F drop across the condenser? This is with the hood up and the pusher fan running, 95°F day.