Stuck a/c line (but not the nut; the junction) - please HELP
 

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 is 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.

Try heating it up with a torch. Get some good heat in there and see if that will get it to move.

Dale

Is a common cigarette lighter enough?

Not even close. You'll need a torch to get it hot enough. A propane torch should do ithttps://cimg9.ibsrv.net/gimg/www.rx7...52908e85f9.jpg

They are cheap, should be like $20-30 or so at most any hardware store.

Dale

if it'.s the aluminum line...I'd be very cautious how much heat you put into it.

It's the aluminium line. Any other idea?

What if i try to insert a sharp blade into junction for prying?

Prying won't help.

Propane torch doesn't get TOO hot, if you were using MAPP gas or oxy/acetylne that would be another story. I would just heat it for a bit, try it, heat it some more, try it.

Dale

Ok and if i use the propane torch your advice is to let the aluminium cool down before start pulling the line?

I have at home a Weller Pyropen that belonged to my dad
https://elektronik-lavpris.dk/files/...989Pyropen.pdf

Pyropen is a soldering iron that uses the same propane ( o i think it is BUTANE non PROPANE) gas of cigarette lighter but can be used also in "torch mode".

Can i use this item?

The reason why the line won't come apart is because corrosion has built up around the stud and the female portion is now corroded to the male portion around the stud. It will be a near miracle to get the lines apart without damaging them. Map gas and a torch may work depending on the location but plan on replacing both lines now in the event that they either do not come apart or the corrosion has caused too much pitting and damage to both lines.

Try rigging up a way to utilize the stud as a puller / pusher if you can. You may have to take the hole hose and line assembly out and put it in a vice. You may have to use a dremel and cut the flange off of one side...

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.

I have another question: my Rx7 vert is an European Turbo 2 model. I didn't find the electric fan on the front of the condenser but if i read the Factory Service Manual the electric fan seems to be present.
I have another friend that owns an Italian Rx7 (coupé version) and even him didn't find any electric fan on the front of the condenser (for European FC Turbo 2 the AC system was standard and not optional. And all European Turbo 2 FC have DENSO - Japan Make - AC system).

Do you think that the electric a/c fan was standard only in some countries?

Thank you very much, my friends.

The electric fan should be standard for the air conditioning equipped cars.

Are you sure?

In all countries?

I read in this forum that someone wrote than only Turbo 2 with a/c have eletric fan, other FC with A/C but not turbo 2 don't have eletric fan.

Mine is a Turbo 2 but european version.

Can you be more specific about this question?

I honestly don't know the answer to that question, but it seems counter productive for Mazda NOT to include the fan in some markets, given it's function as it's described in the FSM. All of the US market series 5 (89 - 91) Turbo coupes had AC as standard equipment, and all were equipped with an auxiliary electric fan in front of the condenser. We didn't get a turbo convertible FC model in the US.

According to the FSM, this fan serves 2 functions on the series 5 FC's: (1) Runs whenever the AC system is running to ensure there's airflow over the condenser, and (2) Runs whenever coolant temperature exceeds about 207*F to provide additional cooling. If you review the FSM text and wiring diagrams, you'll see that, and you'll also find that the S5 cars have a thermal switch to operate the fan (temps > 207F) on the backside of the water pump housing.

My suggestion is to start looking for the specific wiring and components associated with the fan, e.g., the thermal switch, fan relay and wiring as described in the FSM. If all of that stuff is there, then it wouldn't be too hard to source a fan and add it back in.

A mechanic, friend of mine, expert of Mazds Rx just told me that on European FC the a/c electric fan is not present.

I wonder why Mazda made this choice.