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AC condenser hose nut removal

I am trying to remove and replace the AC condenser. The nuts on the lines from the condenser are stuck so I soaked them with PB Blaster and WD 40, I used flare nut wrenches that fit really good, but the lines are very rusty. I twisted the top line and it is ruined, I plan to replace it for $36 from jeepair.com however, I left the bottom nut overnight to see if it will loosen up a little. My question is, can I heat that nut with a Mapp gas torch to loosen it? If not, any other ideas, or other loosening sprays?

Frozen connections at condensors are a very likely reason that many condensor or hose replacement jobs get bigger than initaly intended.

One very frequent “frozen” component in AC systems where I have seldom gotten lucky is the expansion valve that is connected to the rear evaporator in Suburbans,they can get very tough to get off (along with the lines) When you tell the Advisor that things are frozen and you need another 1000.00 worth of parts they usually pop off with “just spray something on it”. Moisture gets attracted to the threads in AC lines and they can get tough or impossible to get off.

Probably 19 out 0f 20 e-36 BMW’s got hoses replaced at the same time the got a condensor because the hoses would not come free.Hey I give it my besy shot but things can’t stop moving because a hose is siezed, I must finish the job and my time too do it is not open ended.

I’d avoid a torch. It will likely not help and may burn through a hose and start a fire.
An air ratchet would would make short work of the nut, if you can borrow or rent the air compressor and tools, do that. If not, try tapping the end of of the wrench with a heavy hammer. You don’t need to kill it, just give it a good tap with say a two pound hammer.

Or else you can slide a solid pipe over your wrench to add a lot of leverage. If you have good tools, they will hold up to the abuse. I admit this is very much a backyard-mechanic approach, but it does work quite well to break stubborn bolts and nuts, providing you have well fitting tools.

Obviously you are forced to use an open wrench (because this is a hose) which is not ideal, especially if the nut is not very big. If you have the correct closed wrench, consider cutting the hose if the nut’s diameter is greater than that of the hose, and using a closed wrench, which applies force to the entire nut and not just 3/5.

I’m in agreement with oldschool. Aluminum corrosion can be a royal pain in the neck at times.

You could try heat but I would recommend keeping it to a minimum. It’s possible this connection could be a permanent one and may never come loose without destroying the line.

Myself I will go on a limb here and say that I lubed the threads on R134A cars (and the O’ring) but for R12 just the O’ring as I was instructed that water is very attracted to R12(oil) (and much less to the oil used for R134A cars). What are others doing to deal with the siezure aspect?

I’d avoid heating anything in an AC system with a torch. It probably won’t help and may cause combustion products or chemical changes to contaminate the system, giving you troubles down the road. You may have to bite bullet and saw it off, and replace more than you bargained for.