AC condenser replacement difficulty?

[brrian]

Yesterday after another muggy drive without working AC I decided to do something about it. After multiple morning trips to rent gauges, a vacuum, and gauges again after the first set didn't work, I've determined that my system leaks, and it's the condenser. I can't pinpoint it because I can't get to it but I pressurized the system & can hear it leaking up there, and if I twist a bit on the lines that run into it, it leaks more or less. So - how hard is it to get the condenser out? Do you get to it on the engine side (radiator, then condenser) or do I have to take the nose off?

 

[69hurstolds]

It sits right in front of the radiator. So whatever is holding the radiator down, dime to donuts it's holding your condenser in place as well. Not sure about GP V6, but it could be a huge plastic piece. There's usually some rubber pads on top and bottom where the condenser sits which is right in front of the radiator. The A/C hoses running in from the compressor and out to the orifice tube will need to be loosened and removed, and the O-rings replaced. Add about an ounce of oil into the new condenser if nothing else is replaced. Don't leave the system open very long. Best bet is to block the hoses removed from the condenser to keep the dessicant from absorbing too much moisture from the air. You didn't say which refrigerant you're using, but it came with mineral oil and R12. If converted to R134a already, you would need PAG or Ester oil, so there's that. Once everything is buttoned back up, evacuate the system and hold a deep vacuum. If it doesn't hold, then don't charge. Make sure it holds a vacuum or you'll be spinning wheels.

BTW, a new condenser would likely be the cross flow type vs. the snaky tube original style. The cross flow type is better. It also mounts thinner, so you may have to cushion the condenser cushions to take up the slack.

 

[565bbchevy]

I replaced the condenser in my 86' Regal with the new style which was thinner and had odd stand offs for mounting but still fit in the original mounting hardware and was still the same snug fit as the original. I definitely questioned the fitment when I had them side by side but there were no issues.

 

[ck80]

You'll want to go in engine side. If 69hurstolds is right, and you're doing it on a grand prix running the 3.8 buick, your order of operations is probably first undoing your upper and lower refrigerant lines while everything is snug in place and setting them aside. Then remove the fan blade at the pulley/pump snout (usually requires a r&i on the v-belts, which, are so cheap if they havent been changed lately is worth the $20 to change the whole set anyways via rockauto), then the plastic fan shroud, and now you can pull the radiator backwards (gently, don't bend your trans fluid cooler lines on the radiator) for clearance without draining the system (unless you're overdue for hoses and coolant change) and undo the two bolt on upper mounts that are rubber in a small clamshell from the top of the core support holding your condenser in. Tilt it backwards towards the engine and it should be able to pop out. Depending on if the car has been apart before you may still have a small plastic baffle on the side of the core support inside that same radiator/condenser bay that helps force airflow around things that attaches by a couple small bolts, but it's an easy quick R&I if it's still there.

I thinknthat ought to cover things, unless someone added an aftermarket oil or trans fluid cooler for some reason.

 

[brrian]

Thanks all - I think I'll take a shot at this. Belts & hoses are new, coolant's been flushed, so good to know I might be able to fish the condenser out without draining the system.

About the PAG oil: my car had been converted to R134A. The ounce I'd add would replace what was in the old condenser (right?) - but how do I know how much is in the system, and if any more needs added?

Edit: I attached a great document I found on understanding & servicing AC systems... putting it here for everybody.

 

[brrian]

Thanks all - I think I'll take a shot at this. Belts & hoses are new, coolant's been flushed, so good to know I might be able to fish the condenser out without draining the system.

About the PAG oil: my car had been converted to R134A. The ounce I'd add would replace what was in the old condenser (right?) - but how do I know how much is in the system, and if any more needs added?

Edit: I attached a great document I found on understanding & servicing AC systems... putting it here for everybody.

Update: I took out the fan shroud and fan, disconnect the trans lines from the radiator, tipped the radiator towards the engine & pulled out the condenser, no problem. I put the new condenser in with 1oz of PAG oil, replaced the orifice tube and some o-rings, closed it all up & vacuumed it out for an hour. & it held vacuum, so I charged it w/ R134A & it blows cold.

I got to thinking though - who knows what oil was in there, and how much? I remembered that there would be some oil in the old compressor, so I drained it out & it's pictured below. Not great?!? There are two separated liquids. One looks clean-ish, feels oily and rises to the top and the other is dirtier, feels gummier and lays in the bottom. & it all has a sort of rubbery smell to it. any guesses - are these two incompatible oils?

In hindsight, I should've flushed it. If I want to flush it now, I have to take it somewhere for refrigerant recovery, right? I don't see any easy DIY way to recover it.

 

[rfpowerdude]

You could buy a recovery unit. That seems to be the only thing you don't have now. You can spend anywhere from $500 to $10k depending on what you want for features (Robinair).
But yes, a shop to recover the refrigerant for you would be best and then you have a clear conscience. Or you could just vent it like just about every shade tree guy has done in the past. Not recommended.

 

[69hurstolds]

Yeah, it’s kinda weird. You spring a seal leak or something and lose all the refrigerant it’s not a major problem. But if you knowingly vent it to the air, you’re technically in violation.

 

[69hurstolds]

That oil mix may be part pag and part mineral oil. If the system wasn’t flushed for the conversion then you could see that. 134a doesn’t mix and carry mineral oil through the system so it just stays where it is.Flushing it is the best way to start out with a known baseline. And ensure you put in a new drier/ accumulator with 134a type desiccant.