Rotary Car Club - Re-installing air conditioning

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- RX-7 3rd Gen Specific (1993-2002) (https://rotarycarclub.com/forumdisplay.php?f=36)

- - Re-installing air conditioning (https://rotarycarclub.com/showthread.php?t=17473)

I'll be damned. Never would have imagined.

Is this the thread/info on R152a you were talking about? I think I'm going to do this too!

http://www.rx7club.com/1st-gen-archi...gerant-997918/

When I put a/c back in my fc last year, I followed that thread you just posted. I used the computer duster stuff, got 2 cans for $10 and had the same 40 degree air temps coming out of the vents as my brother's two new cars. It was great but it developed a leak somewhere over the winter so I have to fix that now.

Sweet! Back when I had AC in the car it wasn't that cold, so I didn't think much about taking it out because I figured it was just not a great system. But the more I heard people talking about theirs blowing really cold I figured I'd put it back in.

Quote:

Originally Posted by speedjunkie (Post 250104)

Is this the thread/info on R152a you were talking about? I think I'm going to do this too!

http://www.rx7club.com/1st-gen-archi...gerant-997918/

Thats it. Just read through and get educated. You can get the AC manifold
cheap at HF and also pick up a vacuum pump thats driven by your compressor
there as well. It works good enough. I've done 3 or 4 systems with just these
tools.

You can do this!

When you say I can do this, are you talking about the whole job, like pulling vacuum, checking for leaks, etc, or are you just talking about charging it with R152a?

Quote:

Originally Posted by speedjunkie (Post 250142)

When you say I can do this, are you talking about the whole job, like pulling vacuum, checking for leaks, etc, or are you just talking about charging it with R152a?

If you get the manifold and the vacuum pump you can do it all yourself. Its
not hard at all.

Well I'm finally getting around to trying to finish the AC job, and I'm going to have some lines made to mate up with the new condenser I picked up to work with my VMIC setup (and I guess have some soft lines made too, I forgot what you guys said about R12 vs. R134a on soft lines), but I'm trying to figure out which way to mount the condenser, as in putting the larger fitting towards the back or the smaller fitting, and which way the lines go...does the skinny line from the firewall go to the condenser or the dryer, etc?

I recently just did this project myself. My evaporator sat uncovered for about 8 years and there was plenty of dirt in there.

For future reference you can easily remove the evaporator without removing the dash (although I know you said you would already have it out).

Absolutely be sure to flush the evaporator VERY good. Additionally, be sure to replace the expansion valve while you have the evaporator out. The expansion valve has a very small orifice in it and one little piece of dirt can screw it up.

Yeah I noticed in another thread that you said you were going to reinstall AC, but I wasn't sure if you'd done it yet. What did you charge it with? Did you have the soft lines remade? Did you use the stock condenser? You have a VMIC right?

I have a VMIC but I found a smaller condenser online and just finished mounting it last night finally. Now I just need a couple lines made. I'm also wondering if there are some kind of quick disconnect fittings just in case it needs to be removed, that way I don't have to evacuate and recharge it every time.

I didn't know you could remove the evaporator with the dash still in, it looks impossible lol.

The evaporator was flushed, but I didn't replace the expansion valve. I searched and searched for one and finally found one that was close, which was listed for an 84 RX-7, but it wasn't exactly the same, and I wasn't sure if I'd do more damage replacing it rather than leaving the old one in there, so I just left it in there for the time being. I'm taking a gamble basically lol. And I'm sad that I didn't replace it now that you're telling me about the small orifice lol.

Quote:

Originally Posted by speedjunkie (Post 263253)

Quick disconnects are not what they are cracked up to be. I had more issues with them leaking than anything else on the jets.

You should be able to find the expansion valve. They are usually pretty cheap(like 20 bucks.) So replacing them is more preventative maintenance/good practice. Since either dirt or use wears them out.

Quote:

Originally Posted by speedjunkie (Post 263253)

I completed the project in the spring. I actually have a FMIC, but it is not the typical FMIC that blocks the entire bumper. Its a custom setup that is inset similar to the blitz kit. I ended up reusing all of the stock parts that I pieced together. Finding a condenser was very difficult. I re-bent stock lines, however if I were to do it over again I would have purchased a custom condenser and made custom lines. I ended up charging it with R134a as a method of testing for leaks. I figured if it could hold R134a then it could absolutely hold any of the HC based refrigerants. The R134a lasted through the summer and the pressure just dropped to the point where the compressor wont come on anymore. I have a couple of bottles of ES-12 I might use.

I believe my leak is due to the fact that I used a compressor from a 99-02 engine. The connection points were larger than the 93 so I ended up using over sized o-rings to make up the difference.

I would ABSOLUTELY replace the expansion valve. It is cheap, and it is likely you got dirt stuck in there while flushing. I went through a few aftermarket ones until I found one that worked. If you have a MANA system (denso is different) then this will work:
https://www.ackits.com/pc/31-12105/M...xpansion+Valve

Quote:

Originally Posted by JL1RX7 (Post 263330)

Quote:

Originally Posted by JhnRX7 (Post 263949)

So did you get a condenser off a different make/model car? I was looking at doing that and I searched by dimensions, but I couldn't find anything that would definitely work, so I did a search for universal ones and found one that is going to work alright I think...
https://www.techchoiceparts.com/inventory/144402
And it was only about $50. One of the fittings is the right size, the other is what I'm getting the line made for, but I guess I'll get the soft lines remade too if I need to. I mounted this about 1.5-2" away from my radiator in the VMIC configuration so I can get some fresh air to the radiator, but hopefully the fans will still pull air through both of them where it's sitting. I may have to drop it a bit more. And I used a universal o-ring kit and replaced all the o-rings in the system. I'm using a stock compressor (possibly the original, but I'm not sure since I have a couple laying around), and I didn't rebuild it. I'm hoping it doesn't leak or anything. I looked for a rebuild kit for that and couldn't find one, but I did find rebuilt compressors. I replaced the dryer with one from Bap/Geon, and it's for a Denso system (mine is MANA), but my buddy has his AC out and had the lines for me to use.

Yeah that looks similar to the expansion valve I picked up and the one in the car. What is the danger/harm if I test the original one first and it turns out bad? Explosions or other damage or just the AC system won't work? It's sad because I'm certified in HVAC for my job but I haven't worked with air conditioners in so many years I really don't remember much lol.

Quote:

Originally Posted by speedjunkie (Post 264039)

I wasn't even sure if QDs for an AC system even existed. I heard they were bad on the jets but we don't have many problems on the GSE.

I found one and it would have worked, but I was afraid I might be replacing it with an inferior part or that I'd mess it up or something, so I figured I'd leave it unless I had issues with the system, then I'd replace it.

So did you get a condenser off a different make/model car? I was looking at doing that and I searched by dimensions, but I couldn't find anything that would definitely work, so I did a search for universal ones and found one that is going to work alright I think...
https://www.techchoiceparts.com/inventory/144402
And it was only about $50. One of the fittings is the right size, the other is what I'm getting the line made for, but I guess I'll get the soft lines remade too if I need to. I mounted this about 1.5-2" away from my radiator in the VMIC configuration so I can get some fresh air to the radiator, but hopefully the fans will still pull air through both of them where it's sitting. I may have to drop it a bit more. And I used a universal o-ring kit and replaced all the o-rings in the system. I'm using a stock compressor (possibly the original, but I'm not sure since I have a couple laying around), and I didn't rebuild it. I'm hoping it doesn't leak or anything. I looked for a rebuild kit for that and couldn't find one, but I did find rebuilt compressors. I replaced the dryer with one from Bap/Geon, and it's for a Denso system (mine is MANA), but my buddy has his AC out and had the lines for me to use.

Yeah that looks similar to the expansion valve I picked up and the one in the car. What is the danger/harm if I test the original one first and it turns out bad? Explosions or other damage or just the AC system won't work? It's sad because I'm certified in HVAC for my job but I haven't worked with air conditioners in so many years I really don't remember much lol.

The expansion valve is essentially a flow orifice. The when high pressure gas/fluid passes through the valve the extreme pressure drop causes the gas/fluid to become chilled. This chilled gas/fluid enters the evaporator where warm air is blown through and the heat exchange takes place to give you nice cold air. Nothing will explode if it is clogged (I dont think), but the AC wont work right. Its such a cheap item you might as well replace it.

I used a stock MANA condenser, but if I were to do it again I would get a custom condenser (larger one for R134a) and have custom soft lines made.