This thread is intended to be informational for anyone with A/C issues, especially with vehicles made prior to 1994 which use the R12 refrigerant, or a problem involving an intermittently working A/C system.



Preface: I bought my 1993 Honda Civic Del Sol Si (this vehicle has the same A/C parts as a 92-93 Civic with A/C, and the parts are also closely related to any 94-00 civic besides possibly the 99-00 Si) in May, and the very next day my A/C was only blowing cold air intermittently. Below are the steps that I took after noticing the A/C was acting up.



Alright, here it goes. These are the steps i took once my A/C took the dive. Readers can learn from the mistakes and successful steps that I took. I will label each step that I took as successful or as a mistake.

1. I went to Advance Auto Parts, with no prior knowledge on A/C besides that it cools the air by removing heat, not just by blowing cold air. I purchased an at-home A/C conversion kit and converted it to R134a.

The typical "at-home" kit includes a few bottles of R134a refrigerant, a single gauge that only reads one side of the system (inaccurate), some horrible instructions, and the R134a type port adapters (so you can fit the R134a filling tools onto the system - the R12 ports are a different size - the refrigerant ports are similar to the valve stems on a tire). To install it, you drain the A/C system of refrigerant and then put the adapters on. Then, with the car on and A/C turned to its maximum setting, you begin adding refrigerant. You shake the can while adding it, and periodically check the pressure. This single gauge is especially inaccurate if the real problem in your A/C system is that the compressor is not working properly, as my problem was similar to this.

This was a mistake.

I should have taken it to the shop and got the 20 dollar A/C check, rather than tackling a problem that I had no knowledge of. R12 systems are not designed to efficiently run R134a, and should at least include replacing the compressor (this may not be necessary, but it recommended because the evacuation/recharge process may not get the R12 oil out that is in the compressor. R12 oil is not compatible with R134a refrigerant.). The shop would have checked my freon levels and told me that they were fine, and I would have known the refrigerant was not the problem. Instead, in the past 3 months I have spent upwards of $100 on R134a, when it turns out I didn't even need to convert. Also, you should not do the conversion your self, you should get the system evacuated and recharged at a shop, as they have the experience with this and the proper tools (a manifold gauge that reads from both the high and low pressure A/C ports and a vacuum machine to pump out all of the R12 and air that might be in the system.) It might be hard to find a shop that can vacuum out your R12, so search around.

Here is a link to is an example of how in-depth an actual 100% proper conversion to R134a is. It also has some very good instructions for anyone wanting to do the conversion.
http://www.honda-tech.com/zerothread/2334672

Here is what an experienced member of the forum had to say about the kit and why it is such a bad option:

2. I kept buying refrigerant and draining and refilling the system because I read that the at-home kit's gauge isn't accurate and can't tell you if you have the right amount of refrigerant. This is because this kit only reads off of one side of the system, rather than from both ports. Instead of investing in a manifold gauge, I tried to buy the correct amount of refrigerant so that I would know how much was in the system just by knowing how much was in the cans.

This was a mistake.

I wasted my money. I should have left it to the pros, or gotten a manifold gauge.


3. I took the car to Firestone to get an A/C check and have the system evacuated/recharged. They found no leaks, but the high pressure side of my system was reading all over the place, so they concluded that my compressor was going bad. They also told me the expansion valve/orifice tube was stuck half open. Since my compressor was bad, they decided to save me money by just draining the system and filling it rather than evacuating/recharging it.

This was both a success and a mistake.

It turns out that they were probably trying to scam me out of my money. I was informed by a member of this forum that it is difficult to determine the performance of the expansion valve when the compressor is not functioning correctly. They probably knew this but wanted me to get it replaced anyway so they could make money off me. Little did they know that i'm a DIYer and I wouldn't pay them $1200 for the compressor and expansion valve replacement when I could do it for less than $500 by doing all the labor myself. The reason it was a mistake is that it's hard to trust someone who just wants your money. The guys at my Firestone seem like many used car salesmen, dishonest and only telling you things to make money. The success is that they tracked down the problem to my compressor, which turned out to be the problem, kind of... I'll get to that later.


4. I replaced my compressor.

This was both a success and possibly a mistake.

It was relatively simple, but might not have been worth it or necessary... i'll never know though. Like I said about the compressor before, I'll get to why it might not have been worth it later.


5. I neglected to replace the Drier/Accumulator.

This was both a success and a mistake.

My A/C, now that I have finally fixed the problem (which actually hasn't happened yet at this point in my steps) works fine with the old drier/accumulator. It is recommended that you change this part whenever you open the system because when exposed to the atmosphere for a certain amount of time it will go bad. Basically, from what I understand that it does, it removes/prevents moisture in the A/C system. The A/C system cools your cabin by removing humidity and heat from the air, not just by blowing cold air. In order for maximum performance, this part should be functioning correctly and doing its job to remove moisture from the system. I read that if you act very quickly (less that just a few minutes) to seal the system back up after removing a part, the drier will remain functional and intact. With this in mind, I removed the compressor lines from the compressor, removed the compressor, and hooked the compressor lines to the new compressor all in a matter of 5-10 minutes. This was a success and my drier is doing just fine now. The mistake I made is that I probably should have spent the extra 5 minutes and $30 to replace it. I recommended replacing it anytime you expose the system to the atmosphere, just as a precaution so that you don't end up with a bad drier and having to get it evacuated/recharged twice ($$$$). I took this chance and was lucky, but it would have been smarter to just replace it as recommended by others. Also, make sure that if you replace it, it is the last thing you do when working on the A/C system so that it isn't exposed to the environment for more than a couple of minutes. If you replace it before you replace the compressor, you have probably just defeated the purpose of replacing the drier/accumulator.

6. I had the system evacuated and recharged.

This was a success.

It cost me $125, but I am glad I spent that money as getting it properly evacuated is a very important step to protect the new compressor from any R12 that could be in the lines after a normal drain and refill. Also, now I know that my system has finally been properly converted to R134a and I can expect to not experience any problems with R12/R134a compatibility.



What happened next: So, after all of these steps, Tires Plus (who did the evactuation/recharge) called me and informed me that my car was ready and was blowing cold air. I got a ride down there and paid. I got in my car, turned the A/C on, and it was blowing relatively cold, but not as cold as i had expected. I drove away satisfied that it was better before and that it was all I could hope for. Well about 1/4 mile down the road, it started blowing warm air. I got home and called Tires Plus about a billing issue (they forgot to enter my $10 off coupon), and I had to drive back to receive my $10. I got my $10, and had them take a second look at my car. Within 5 minutes, the mechanic came back and asked me to come out there so he could show me what he found. There is a relay next to the condenser/condenser fan unit that turns the compressor on whenever you turn the A/C on. Well it turns out, this relay was functioning intermittently. He tapped it a little, and my compressor turned on, and soon turned off. He then squeezed the relay, and it stayed on. I drove it home and replaced it with a new relay that I just out of luck happened to already have a spare one of. Well, now my A/C works flawlessly.



Earlier unexplained thoughts: The reason having my A/C checked at Firestone was a mistake is because they obviously didn't notice that whenever their gauge was reading all over the place the compressor must have been turning on and off. However, relying on the experience of the mechanics at any particular auto repair shop is always a risk, and there is no way to know ahead of time if they will actually pinpoint the cause of your problem or not. I suggest taking your car to a trusted mechanic or shop. I trust my local Tires Plus a lot, but they didn't have the tools to deal with my R12 system, so I was forced to take the car to a shop I had no prior experience with. Ironically, the shop that actually found my problem's source was Tires Plus.
Kudos to the employees at the Titusville, FL Tires Plus. They always seem to accurately find my cars problems whenever I can't find the problem myself, and are really cool guys.

The reason replacing my compressor was possibly a mistake is that it might not have been anything wrong with it other than the relay that controls its engagement. The reason it might not have been a mistake is because my old compressor may have been blown from mixing R12 oil with R134 refrigerant and some remants of R12 refrigerant.



Conclusion: I cannot stress more the importance of checking this relay before replacing parts/putting refrigerant into play. If I had checked my relay first, as soon as the problem started, I would have repaired my A/C for free, as I actually had a brand new relay in the electrical parts drawer in my toolbox, still in the packaging. Instead, I have spent around 600 unnecessary dollars fixing it. I do not regret a bit of it though, as I have learned a lot from the experience, I now have a successful R134a conversion (it works fine; although, I didn't replace all of the parts that I should have), a new compressor that works better than the old one probably would have, and some good information to share with my fellow HCF members.



I wish good luck to anyone attempting to repair their A/C.

 

sticky?

 

Very nice. I think this write up has both good advice and important lessons for anyone contemplating A/C work or an R12 to R134a conversion.

 

thanks

 

Just an afterthought. Maybe it would be helpful to mention what the contents are in the at-home A/C conversion kit and how they were installed.

 

^edited to include this info, it shows how incomplete the kits are

 

Do not use that kit. Those familiar with it's results call it a "death kit". It contains one little can of "conversion oil" which is inadequate. You're supposed to just put that oil in without removing your old oil.

The old oil doesn't react with R-134a, but it just sits there and will be in the way of proper refrigerant flow and cooling if you don't remove it. You need to remove the compressor and drain it, and refill with a sufficient amount of R-134a compatible oil. Compatible oil means that it will mix with the R-134a and move around the system and keep coming back to the compressor. Usually conversions are done with "Ester" type refrigeration oil. The old mineral type oil will leave the compressor and not come back, and the compressor will run dry and fail. The more of the mineral oil you can get out, the better. Replacing the receiver-drier is essential because it has a bunch of oil trapped in it.

Civics from 1988 up have a scroll type compressor. The output high side pressure normally pulsates as the unit rotates especially at idle speed. Inexperienced techs can confuse that situation with what they've seen from a typical multi-cylinder piston compressor with faulty valves or cylinders. This seems to be what happened at Firestone.

The latest version of the death kit is even deadlier because the 3 cans of refrigerant in it are no longer plain R-134a, they have some sort of sealer or something in it. Never put sealer into your system. It doesn't stop leaks. It does stop up your expansion valve, condenser, etc. You will have to replace the entire system to get rid of it. If you have a leak, find and repair it properly. Use only plain R-134a. If you're expecting to use a lot of it, like working on several cars, you can buy it in 30 pound tanks. Anyone is allowed to buy these tanks but parts stores usually keep them behind the counter and you have to ask for them (same way you get a real manifold gauge instead of the useless single gauge on a hose that's out on the floor). You also need an accurate scale to weigh the tank while charging to know how much you're putting in. The cost of R-134a in the big tank is so much less than in 12 oz cans that the scale will be paid for by the time you've used the first tank.

 

This is very important input. Would it be possible for you to outline the general steps required for proper conversion from the Civic R12 system to the R134a system, and also to mention A/C components/kits that should be purchased? I think many members would be interested.

Do you think conversion information at the link below is a good resource?

http://www.honda-tech.com/zerothread/2334672

 

i will edit my first post to include that link and I will put in a quote of what mk said

EDIT: alright, done editing to include the above mentioned

 

bump, sticky?