'85 300CD: Replace condensor while I'm replacing radiator?
 

In my 1985 300CD, the radiator is showing seepage (the white powder
stuff) around the top where the crimping is. This car has the
original cooling system hoses also. I am planning on replacing all
of the cooling system hoses and radiator as soon as it cools down
here in Phoenix, Arizona.

Also, I am planning to do a complete rebuild of the A/C system
(staying with R-12). That is, replace the compressor,
receiver/dryer, etc. The flushing and all of that. Will probably
put in a rebuilt pushbutton unit from Programa. The A/C system has
had a leak(s) for years. No surprise, the car is 25 years old.

My question: While I am replacing the failing radiator, should I
also replace the condenser? My view: It is 25 yrs. old and why be
so careful with an A/C rebuild and at the same time rely on a 25
yr. old condenser to stay good for another 10-20 yrs.

I figure (though I am not sure) that replacing the condenser is
easier when you’re also replacing the radiator on this vehicle.
True or false?

Thanks-

not really. unless the condenser has ingested water resulting in acid that damages the coils. or the fins are damaged from debris, I'd just flush it well internally, and clean the coils externally with strong detergent designed for condenser cleaning.
the 85 is the best year for the condenser, so unless you are planning on upgrading to a parallel flow and building your own fittings etc, it's best to keep it stock... of course in arizona, you need all the a/c you can get, and black tinted windows to boot... adding a 2nd condenser wouldn't be out of the question!

After you have done it once, removing the radiator is a 15-minute job. Having it out is hardly justification for replacing a working condenser.

Check the condensor for any signs of damage from errant stones. Usually a good sized oily spot. I had stones take out condensors in other cars.

How is the '85 condensor better than say the '82?

in 85 they made improvements in the surface area of the coils. the SD got MASSIVELY more, but the 123's did get smaller tubes, so more refrigerant is in contact with the surface of the tubing. gives a slightly better condensing action.

can a w126 unit be retrofitted to a w123?

I doubt it. lots taller and longer. the fittings should work if you could make it go in the hole. i have a broken one with a rock hole in the thing. I could try and make it go in one of my 123's... when I'm bored with nothing to do... (*quite hectic at the moment...)

vs maybe I should come down to NC for a week and pay you to do all sorts of stuff to my car...

you better make an appointment! i have 4 customer cars in various stages of restoration at the moment! (and Thayer's car keeps coming back...)
But I'd be Happy to help when I can!

Ok. I'll check the condition of the condenser when I'm replacing the radiator. Thanks for the help-