I have a 1991 honda civic si that had its AC components "removed" by the previous owner. I love the car but its unbearable to drive during the heat. Now, I have a 2017 civic hatch that I use when it gets way too hot but I wanted to know if it was possible to "add" the AC components back into the car?

IIRC the 88-91 Civics, used the R12 refrigerant which needs to be evacuated by a certified tech. Does that mean that the compressor, lines, and condenser need to be swapped? Or can I use R134 in those components as well?

Whats a good brand for compressors? Matsushida? Is that the OEM brand used by Honda?

 

freeze-12 worked fine for me as an r12 replacement with OEM system.

im pretty sure there were two compressors available. you just had to match the pulley and belt.

i know someone who tried to piece their AC together. it failed. but he didnt have the patience to diagnose things. theres a lot of troubleshooting involved if things dont work. like relays and pressure switches, etc.

when these were new at the dealer, you could buy AC separately and have it installed. however at this point you cant just buy a new full kit and have it installed. youre left with junkyard parts which you just dont know works or not, and probably contaminated.

 

I see.

I'm willing to troubleshoot things. I need that AC.

I think the car came with AC from the factory but was taken out by the previous owner. In this case, I will need a compressor, condenser, and the AC lines.

Should i just retrofit it with R134A while im at it?

 

I'm in the middle of doing the same. I decided to go with the TRS090 a/c compressor from the 94-95 civic. And the ADPI/PRO 7014236 condenser from rockauto. It's a factory replacement condenser for the EF civic, but is parallel flow style which I guess is preferred for the R134A a/c systems. There are a few threads about the conversion, you need to source/modify CRV/94-95 civic compressor lines, get a eg a/c bracket, etc.

 

I put AC in my RT Wagon that had no AC. All the parts were sourced from a wrecking yard EX Sedan. Put a new compressor in it and filled it with r134 and PAG oil. AC blows cold even on 100 degree days.

The AC installs of the period were all kits, I don't think anything came from the Honda assembly line with AC installed. Fairly certain all the 88-91 Civics used the same kit.

 

But were the kits from Honda? It seems that I might have to piece together a kit from other D series motors.

I'm assuming you had to fab a bracket to mount the EG compressor? Or all are D series compressors the same ?

 

i guess you missed the implication that Freeze-12 is a direct replacement....

if your compressor and rest of the system arent made for r134A, theres no point in "retrofitting".

 

Sure. But i dont have my compressor or the rest of the system. So when I go to put a replacement compressor, lines and condensor back in, i should just pump it with R134a ?

Edit - but the car did come with AC as i do see service fittings coming out from the firewall. .....

 

The bracket from the EG mounts to the EF D series motor. Actually I have B swap, which in my case I'm using a 99 CRV bracket.

 

Yes the AC kits were a Honda part.

The problem with R12 today is the price and sourcing it. R134 works fine if you also replace the oil in the system. Oil for R12 is not compatible with oil for R134.

AC compressor brackets are specific to the compressor. In the EFs there was a Sanden pump and a Matsushita/Panasonic pump. Sandens had the smaller pulley and are the preferred pump. You will need an EF bracket as the EG added a motor mount to the AC bracket.

I have found one down side, the AC won't turn on if the outside air temp is below 34 degrees. The R134 has a lower vapor pressure than R12 and won't produce enough pressure to trip the low pressure switch. Kind of a big deal when you want to remove moisture from the glass in winter. I think a pressure switch from an EG will fit but I have not tired.

 

Thanks for your insight man. And I dont think ill have to worry about temperatures sub 30*. I live in socal. Temperatures at its COLDEST get to maybe 65* during the day time.

 

mikecp i sent you a pm

 

I've done a full parallel flow condenser conversion from Ackits back in 2011. These cars absolutely suck with R134a if you live in any kind of hot/humid climate. I've gotten Sunfires, EK's, and even Sonatas down to 40f idle on a 90f day with no issues, but these cars will not cool worth a damn. Ironically, I was considering getting rid of my '90 Si for a 2017 hatch. I live in Orlando and the damn thing still never REALLY cools unless it's moving despite many different approaches with the A/C.

Are you familiar with evacuating and charging an A/C unit? You're going to need some special equipment if you aren't---or it's going to fail in a spectacular fashion. The 4th gen Civic also takes only around 4oz of oil TOTAL (lines flushed and new parts). Too much oil and your A/C pressure will skyrocket on both sides and not cool. Be very careful.

I recommend referencing this post for a few suggestions regarding condenser installation: https://honda-tech.com/forums/honda-...quiry-3205952/ I know some links are dead, but you need to make absolutely sure your condenser is sealed to the radiator and you have two fans.

Please let me know if you have any further questions and I'll try to get back to you. This car is a dying breed and to inquire about A/C is even worse considering less and less people are daily driving these cars.

 

It's a 30 year old design, not fair to compare it to something modern.

 

Which leads me to wonder if using R12 will be better than switching it to R134a

Edit - my brain is thinking, if its 30 years old, give it something that was used at the time...rather than swapping it for a modern one and having it barely cool.

 

FWIW, i had a working OEM A/C with what i assume was original r12 but had to break the line and lost what was under pressure. (i dont care about the insignificant environmental or legality of releasing r12, so whatever)

Freeze 12 (3 cans i think?) and an extra can of oil worked. did not evacuate, vacuum suck anything, etc. in fact to get better results i had to release some pressure after filling things up. was working for several years fine in Socal heat

alternatively, on my 2006 TSX I tried the store r134a cans to restore pressure after releasing replacing the AC clutch, and it worked ok, but not enough. I had a AC pro evacuate and do things right and it worked amazing. there was definitely a difference. im very much appreciative of it currently with the heat and humidity so bad here this week.

YMMV

ps, yes i know freeze-12 is some majority percent of r134a, as well as R-142b. but it worked in my OEM system just fine and if r-142b is whats needed to make it work without doing anything else, great. there were not retrofit fittings needed.

 

A/C work is cumbersome. It can be incredibly hard sometimes to fix a system properly. If you really have to ask serious questions, it's better to take it to a shop. I don't mean that as an insult, it's just that A/C systems are that sensitive. You should let us know what kind of equipment you have. There isn't a single A/C system on the market that can tolerate being charged outside of a deep vacuum and work within OEM specs.

We can help you here with specs and procedures, but if you don't have the equipment, I wouldn't even bother... You could turn your compressor into a hand grenade and have a host of other issues.

 

Oh no, i completely understand. and i dont intend to treat this like a simple oil change. I will most definitely take it to a professional. But the system being so old, I just hope that they dont laugh at my face or stare at me like I'm bringing them some kind of alien technology.

I guess we really got off topic but hey I learned a lot!

 

I can tell you that my 91 crx went from r12 to freeze12 to 134 and never worked worth a damn. My 88 crx has been r12 since new, obviously. I have never fugged with it and just sourced r12 from eBay and CL. I still have 10 cans to keep her going. I just replaced the radiator, and now I can drive in 100 degree heat and the AC blows nice and cold. I have replaced the compressor a few times for sure.

 

In 2011 I did the R134a retrofit in my 89 CRX Si with a parallel flow condenser, used Sanden style compressor my friend gave me, Supercool PAG-46 and all new o-rings & drier (everything else left original). The cars AC is great. Even if it's 105* outside, the system will still eventually cycle on/off on the freeway when set to max (speed 4 + recirculate). Puts my EG's AC to shame.

I've had other electrical problems (switch, fuse & clutch issues) since then, but the compressor is still pumping strong with R134a.

 

who has a parts list for the 94-95 compressor upgrade? Have searched for other threads.
thanjks