smokin a/c

[MacCoug]

I bought a 72 C10 about 3 weeks ago. I've been having a little trouble with the a/c since I got it. Nothing major, just doesn't seem to produce air that's very cool.

With that in mind, yesterday on my way home (it's a daily driver) I started to smell coolant. When I parked in the driveway coolant appeared to be leaking from the a/c unit.

I've never worked on a/c, so I have a few questions. First, does coolant run through the a/c unit to cool it down or does Freon look/smell like coolant?!

Also, since it did appear to be coolant, I topped off the radiator (it was down about 3-4") and once the truck warmed up this morning, it was blowing smoke through the vents (with the a/c or heater on) and more coolant was draining out of the a/c unit.

Oh gurus of the bowtie, Help!

[bobthecop]

Sounds like a heater core leak

[poff]

There is no coolant in the A/C system. They really only share the heater fan and engine fan other that that they are fairly independent. The heater core is in the same housing as the A/C evaporator. You probably need a hose or heater core. Make sure your heater & A/C controls are working correctly. If the flaps are not moving to the correct location or are not sealing you could be getting heat from the heater at the same time as the A/C is running. If this is the case the refrigerant will absorb the heat from the heater and not the passenger compartment. If the controls and flaps are OK you may need to charge the A/C.

[MacCoug]

thank you both, should I be wary about replacing the heater core as a novice? Also, is there a way to check the flap between the heater & A/C?

[killer71]

Definetly sounds like you have a heater core/hose problem if you are smelling the antifreeze through your vents and are notably leaking coolant. Also sounds like your ac system is low on freon and probably low on ac compressor oil. That smoke you see is usually and indicator that your ac system is freezing up which is an indicator that you are low of coolant.

[DAJ 67]

[MacCoug]

thanks. I was just reading through a couple posts in the tech section and it sounds like replacing the heater core isn't too bad with the a/c units. Sounds like my next steps are:
1) inspect/replace heater core & tubes
2) have a/c checked (or could I?)
3) check coolant & freon levels

It's also nice to see others getting a fog of coolant... misery loves company!

[poff]

The only problem with A/C is that they do not manufacture Freon (R-12) anymore. If your truck has not been retrofitted to use R134a you may have trouble finding Freon. If you are low or out of Freon you may need to retrofit.

[WorkinLonghorn]

The only problem with A/C is that they do not manufacture Freon (R-12) anymore. If your truck has not been retrofitted to use R134a you may have trouble finding Freon. If you are low or out of Freon you may need to retrofit.
__________________
'70 K-20 San Diego, CA

I have found that "Freeze-12" at Pep Boys and other places (behind the counter at Pep Boys-you have to ask for it) works almost as well as R-12.
For the time being,until you fix the leak,disconnect the heater hoses and loop one back to the engine,bypassing the heater. Then at least you can drive around without having to wipe the windshield every 30 seconds.(Plus inhaling antifreeze is not good). DO NOT run the AC until you have checked it out.

[MacCoug]

Originally Posted by WorkinLonghorn

For the time being,until you fix the leak,disconnect the heater hoses and loop one back to the engine,bypassing the heater. DO NOT run the AC until you have checked it out.

Thanks for the tip. I did that over the weekend and it worked great. I found out it has been retrofitted for r134, so that should help. I'll get the a/c looked at.

Also, I checked NAPA and a core is $52. Does that sound right?

[bobthecop]

That price sounds ok to me.