Re-installing air conditioning

[speedjunkie]

I removed my AC back in 2008 when I put my VMIC in, since it was going to take longer than I wanted to spend at the time to mount everything back in there, due to the different angle of the condenser and so forth. But after looking at everything it doesn't look like it will be that bad. I'm gathering all the pieces to put my AC back in, and I know I need to replace the separator so I already ordered one from Ray, but I'm wondering what else I should replace. I have all the pieces, although my condenser is pretty beat up, but I got another one of those. Also, I didn't close off my lines going into the evaporator (that stick out through the firewall into the engine bay), so I'm not sure how much dirt and crud is inside there now and I'd like to make sure it's cleaned out inside. I'm pulling the dash to get the heater core fixed so I can have heat again too, so while I'm in there I'm going to take out the evaporator and clean it up like I've seen on some other threads recently (Theorie lol).

My compressor is pretty nasty but I'm going to clean it up and make sure it's good. I'm just wondering about any seals in there, if I should replace them. I asked Ray about a rebuild kit for the compressor but Mazda no longer has them. I also asked about an o-ring kit for the lines but it would be $60+ for all those from Mazda so I'll buy a kit from a parts store.

So far I've checked to make sure the lines clear the single turbo and that I'll have room for the separator next to the VMIC, and amazingly enough it looks like all that will work. I'll have to bend the lines a bit so it will hook up to the condenser in it's new orientation, and I'll have to cut holes or slots or something in the ducting for the lines to go through, but I'm not too worried about that. I do remembering practically having to pull the engine to get the compressor out since the mounting bolts are so long, but I figure I'll just put them through the holes and then mount it instead of trying to hold it up and then slide the bolts through.

One thing that just crossed my mind...my AC/PS bracket is powdercoated, I'm hoping the compressor doesn't need to be grounded to that. If so, I'll have to take off some of the coating. I'm also going to heat wrap the hard lines going past the turbo. I know it probably doesn't matter functionally, but it will also help to cover up the ugliness of the lines since they're dinged up in a few places lol. I'm going to take off the black foam that came on them, it's all dry and brittle anyway.

Anything else you guys can think of that I need to check? I don't want to be pulling and replacing stuff because something's leaking or whatever. I want to install this stuff and be done with it.

[GySgtFrank]

I had new lines made for my SA down at the local shop that builds hydraulic lines. Pretty cheap actually. Mine were dry rotted and blown out, but it might be realtively cheap insurance on yours to replace them, since they're getting pretty old by now if they're still the stock lines.

[speedjunkie]

Well most of the line is aluminum hard line. Or are you talking about the flexible portions? Those parts are in pretty good shape, it's just the aluminum portions are dirty and dinged up so I was going to cover them, but I at least wanted to clean them out inside too. I'll look over the flexible portions of the lines though. Thanks for your input, Gunny!

[GySgtFrank]

Yeah, mine are mostly flexible so more vulnerable to rot than yours.

[speedjunkie]

I looked at the lines real quick and they looked alright, but I'm going to inspect them more in depth. I also cleaned the compressor and I found 3 of the 4 mounting bolts. ARGH!!!! lol I have so many parts, I have to have another one somewhere.

[Whizbang]

seals would be a good idea.


or a bucket of ice and a 12v fan

[speedjunkie]

Seals in the compressor?

Nah I'd rather have AC back in lol. I've dreaded this project for the last few years, but I'm actually kinda looking forward to it now.

[Whizbang]

at all the connection points. those little o-rings

[speedjunkie]

Yeah that's what I was talking about in my first post. For all the little orings from Mazda it would have been $60+ Ray said. I can get a whole kit from O'Reilly for $13 lol.

[Pete_89T2]

I'm by no means an A/C expert, but I picked up a few good tips from this automotive A/C forum I found online when my FC's A/C crapped out and was in need of some repairs:

http://www.autoacforum.com/

Couple of tips I would suggest are:

(a) Replace all the O-rings in the lines

(b) Install a new receiver/dryer

(c) Replace all the soft lines, especially if you're switching over from R12 to the R134 refrigerant. (Soft lines made for R12 won't contain R134 over the long term because the R134 molecules are a lot smaller than R12, go figure!)

(d) If you can find a rebuild kit, I'd replace all the seals/soft parts in the compressor. The A/C forum can probably help you here because the Nippon Denso or Sanden compressors that were used on the FB/FC/FD's are common to a lots of other cars, and the repair/rebuild kits should still be available Look for a part # or ID tag on your compressor to try to figure out what you have as a starting point.

Another thing I'd suggest since your A/C has been open to the elements for a long time is flushing all the components you'll be reusing (evaporator core, condenser, hard lines, etc.) with the appropriate solvent for whatever refrigerant & oil you had in there or plan to use when you close it up. This is another area I'd seek out better advice though, because there are chemical compatibility gotcha's to deal with.

Good luck with the A/C work.

[speedjunkie]

a) Definitely getting a seal kit

b) Ordered a new dryer from Ray Crowe, ~$150 YIKES! Would have been $200+ without Ray's discount, he's the man!

c) I was reading a thread on the evil forum and the guys were saying ES-12 gets way colder than R134a and is pretty similar to R12.

d) Someone in that thread also said that one of the Toyota trucks uses the same exact compressor, TV-14 I think is what it is. I'll look into a rebuild kit for that I guess. Thanks for the idea!

Yeah I definitely want flush all the components. I want this system to be as like-new as possible.

Thanks for your input!

[t_g_farrell]

Looks like most of the obvious has been covered. New soft lines ARE required if this was an
R12 system before and you go with newer coolant like R134.

Speaking of coolant, I've used R152a (DustOff in the can from staples) in my wifes BMW
over a year ago when I replaced the compressor due to its demise after 140K miles. Its
still working great, no leaks, no issues and it performs as well as R12 and a lot better than
the R134 that was in there before. Plus its dirt cheap compared to the R134 or any other
coolant out there especially when Staples puts it on sale. Theres a sticky on the evil
forum first gen section that has a detailed discussion about the merits and the tech
data posted up about its temp/pressure characteristics.

I'm also reinstalling the AC on my SA and it will get the DustOff treatment as well. My
lines are being made as we speak.

[Pete_89T2]

If ES12 is the same stuff I think it is, it's based on propane/butane. Check with someone more knowlegeable than the evil forum on that since flamable stuff in the AC just sounds like a bad idea.

[speedjunkie]

^I'm going to take it to a shop to have them leak test it and charge it rather than doing that myself. I want to make sure it's good. They were saying use the industrial ES-12 for the coldest air. And some of those guys are using it already, so I'm assuming it's not the same stuff you're thinking of lol. But maybe it is, who knows.

First I need to find out what my system used. I never charged it so I have no idea. It's a 94 Touring and after looking at the FSM I believe I have the MANA system as opposed to Nippon Denso, going off of which dryer/separator I have anyway.

How in the hell do you charge it with Dustoff? LOL I'll have to look that up.

[t_g_farrell]

How in the hell do you charge it with Dustoff? LOL I'll have to look that up.

Requires a vampire type tool that punctures and seals the can so you can hold
it and hook it up to your AC charging hose setup.

Looks like this:

http://shop.advanceautoparts.com/wcsstore/CVWEB/staticproductimage//N3570/detail/20892203_faa_69445_pri_detl.jpg

[speedjunkie]

I'll be damned. Never would have imagined.

[speedjunkie]

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-archive-71/c-charging-easy-cheap-safe-alternative-refrigerant-997918/

[antman0408]

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.

[speedjunkie]

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.

[t_g_farrell]

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-archive-71/c-charging-easy-cheap-safe-alternative-refrigerant-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!

[speedjunkie]

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?

[t_g_farrell]

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.

[speedjunkie]

Gotcha. Thanks!

[speedjunkie]

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?

[JhnRX7]

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.

[speedjunkie]

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.

[JL1RX7]

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.

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.

[JhnRX7]

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.

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/Mazda94RX7_1-3/31-12105+-+Expansion+Valve

[speedjunkie]

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.

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.

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/Mazda94RX7_1-3/31-12105+-+Expansion+Valve

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.

[JhnRX7]

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.

[speedjunkie]

Thanks! Well if I have problems with it I'll replace it this winter.

Oh OK. I had my original condenser but it was too beat up, so I found another one and bought it, but then when I removed my ducting I discovered the stock condenser was still too wide for where I was mounting it, so I opted for the universal one. Why are you getting a larger condenser for R134a? I'm planning on using the same refrigerant but my condenser is smaller than the stock one.

[RXtacy]

Thanks! Well if I have problems with it I'll replace it this winter.

Oh OK. I had my original condenser but it was too beat up, so I found another one and bought it, but then when I removed my ducting I discovered the stock condenser was still too wide for where I was mounting it, so I opted for the universal one. Why are you getting a larger condenser for R134a? I'm planning on using the same refrigerant but my condenser is smaller than the stock one.

R134a is less efficient than R12, and therefore needs a larger condenser to achieve the same ⌂T. IE the conditioned air won't be as cold.

[speedjunkie]

Dammit. lol Well maybe I'll keep an eye out for a more efficient refrigerant, because I really don't feel like reworking my whole system to fit a larger condenser. Or I'll just try R134a first. It's not like it gets SUPER hot here anyway.

[RXtacy]

If ES12 is the same stuff I think it is, it's based on propane/butane. Check with someone more knowlegeable than the evil forum on that since flamable stuff in the AC just sounds like a bad idea.

Lots of refrigerants are hydrocarbon based, that's nothing new. R-134a is tetraflouroethane, and R-12 is Dichlorodiflouromethane for example.

Dammit. lol Well maybe I'll keep an eye out for a more efficient refrigerant, because I really don't feel like reworking my whole system to fit a larger condenser. Or I'll just try R134a first. It's not like it gets SUPER hot here anyway.

Definitely give it a shot. I would also not hesitate to run ES-12 if 134a doesn't work. ES-12 should be similar to R-12 efficiency wise.

[t_g_farrell]

Dammit. lol Well maybe I'll keep an eye out for a more efficient refrigerant, because I really don't feel like reworking my whole system to fit a larger condenser. Or I'll just try R134a first. It's not like it gets SUPER hot here anyway.

DustOff FTW! Its has the same cooling characteristics as R12 and is loads
cheaper. Also will work well with existing condenser.

[antman0408]

I fixed the leak in my system this summer and charged it with the duster stuff. 2 cans for $10, it's cheap enough that I would just try it with this stuff first and see how it works in your car.

[speedjunkie]

Well I was planning on trying DustOff or something but then I was reading about it being flammable and all that. So I started looking at more conventional stuff.