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Stuck ac line (but not the nut, the junction)

Posted: Mon May 07, 2018 10:59 am
by Venturer
Hello everyone.

I'm the owner of a beautiful 1991 Mazda Rx7 Convertible.

I'm restoring the ac system changing all the o rings.

Al the lines came off easily. The only line giving me a lot of trouble is the one that is on the enter side of the condender (the one that is from the high pressure side of the compressor).

I had not troubles to unscrew the nut (all the nuts of the system are in perfect state, no corrosion), problem is that the junction is freezed. I tried to pullout the junction but it's blocked. I think perhaps that the o ring inside is melted or there was a small oxidation melting.

What can i do now? I sprayed a lot of penetrating oil in the small slot beetween the junction but the joint is so accurate that i can't insert even a small screwdriver into it (it will ruin the coupling) for pry the joint.

I don't want to cut the line. Can you help me please?

Thank you very much.

Re: Stuck ac line (but not the nut, the junction)

Posted: Tue May 08, 2018 5:28 am
by Cusser
Have you tried to warm the outer fitting with a propane torch? And then maybe try to turn the flexible line's fitting?

Re: Stuck ac line (but not the nut, the junction)

Posted: Tue May 08, 2018 10:57 am
by Venturer
I tried to heat the junction with a cigarette lighter.

I don't want to use a propane torch because it's the aluminium line and i fear that the heat can melt the aluminium.

What is i try to insert a sharp blade into the junction and i try to pry?

Re: Stuck ac line (but not the nut, the junction)

Posted: Wed May 09, 2018 6:22 am
by Dougflas
Post a photo

Re: Stuck ac line (but not the nut, the junction)

Posted: Wed May 09, 2018 9:47 am
by Tim
Map gas should not deform unless you just hold it in one position for an extended period.

Re: Stuck ac line (but not the nut, the junction)

Posted: Thu May 10, 2018 10:35 am
by Venturer
I did it! With butane/propane torch of my small gas iron welder (weller pyropen). I heated the aluminium then i turned the stud circle way down ad up and it slowly breaked the oxidation. Metal does not seem damaged, it was just a little dirted.

I hope i did'nt stressed much the junction with the heat.