Hello, The air-conditioning system on my '93 Accord wagon is not blowing cold air and I need to diagnose, but I'm not sure how to proceed. Here's what I know:

- AC does not blow cold air (duh), inoperative most of 2013 IIRC
- With car running, interior events activated, AC button pressed:
- Compressor clutch does not engage
- 2 big (cooling?) fans behind radiator do not spin
- The mechanic who helped my wife select the car said she has a small leak somewhere
- I depressed the Schrader valve on the line that runs behind/along the top of the radiator (I don't know if this is the high or low line, see image) there was a weak hiss that quickly dissipated, then nothing



- I cannot find the valve for the other line. That line just comes out of the compressor and goes into the front of the vehicle to the condenser.

My questions:

- I to DIY as much as possible, but what should I do first?
- How do I know if I have R12 or R134?

 

First step is to find the leak. You can sometimes locate the leak visually by looking for a buildup of oil/dirt at or near the leak site. As leak occurs, lubricant is lost which attracts dirt.

Likely spots for leaks are crimp fittings on hoses, compressor clutch (look for ring of oil/dirt around the clutch rotation plane, condensor face, and connections. Unfortunately, leaks in the evaporator connections are also likely and can't be seen. Only a shop compressed N2+R134a test using refrigerant detectors can confirm evaporator leak, but w/ age of vehicle they are highly likely.

My suggestion would be to simply overhaul the system and retrofit to R134a as a DIY project. This would require:

1) remove evaporator and replace all orings (thermal bulb, expansion valve) w/ R134a compatible orings
2) replacing or repairing compressor, if leaking
3) replace all system connection (compressor, condensor, evaporator) oring seals w/ R134a compatible seals.
4) Install good quality retrofit fittings
5) Replace receiver/drier w/ R134a compatible unit.
6) Perform a vacuum leak test (it should hold vacuum for 1/2 hr).
7) Flush and recharge system (either buy equipment or pay someone to install lubricant and R134a).

good luck

 

Dido the above. I would get a can of UV detector refrigerant with test light and glasses and go over the entire system to find the leak(s). After that replace as needed. Also check that you can rotate the compressor clutch by hand because if that has seized then you will have to deal with that as well as the leak(s).

 

That is the correct way of addressing the OP's issue. but on a 93 Accord may cost more than the vehicle is worth considering lines breaking trying to take them apart and other issues doing the repair. I would suggest installing the R134a kit per instructions and see how long the charge last first.

 

Thanks so much TexasHonda!

Kris, when you say install a new "R134a kit" do you mean just put a new canister of coolant in it and see how long it goes?

 

What they are saying is the 93 came with R12. Which is hard to find and if you do find it - the price is high.

So if the car has not been converted to r134 already, now is the time. There are "retro" kits you can buy. Install that and see what you have from there.

 

Ok, so today I bought a 10.25oz can of R134a refrigerant that included leak-stop and UV Dye.

The can connector fit perfectly on the port I referenced in my original post. The only other port I found was behind the headlight and on a smaller line so I'm now sure that I used the correct service port on the Low line. Also, the port I used had clearly been fitted with an R134a connection. The other port appeared not to have been retro fitted.

This leads me to believe someone already retro fitted this vehicle and used the R134 freon.

Because the compressor clutch would not engage, I found the relay and shorted it to force it to turn on while I added the freon.

I immediately noticed a bad leak coming from a hose connection right next to the service port (see the video)


So obviously there's probably a bad O-ring. Now that I located this leak, assuming there are no other leaks....

- Should I attempt to change ALL the O-Rings, or just the leaking one I found?
- Can I empty the system myself to change the O-ring and receiver/dryer?
- Should I be concerned about having a "compatible" compressor?

Thanks for all the help, I'm serious about putting to use what I learn.

 

The "law" says that you should "recover" the gas that is still in the system.

I would go ahead and get an o-ring kit for the car - many stores sell a kit that is specific for a certain year/model car. It will come with all of the o-rings/gaskets for the AC system. Not saying you have to replace all of them if you don't want to but at least you have them all.

Replace the one you know is bad and the drier. Pull a vac on the system, does it hold? If not, time to find the "other leaks". Once you get it sealed up properly, you really need to think about adding some oil back to the system - the amount will depend on what all you end up doing?

 

Thanks,

Would it be prudent to "flush" the system somehow? How is this done?

 

This depends on what you plan on doing to the a/c system.

If you are going to replace all of the o-rings, then you can drain out the PEG oil from the components and add new stuff. If you are going to fix the leaking o-ring, then I wouldn't worry about the oil.

I'd look at every connection in the engine bay for signs of that dye. Also look around the compressor pulley.

A/C repair is one of those things that would you want to do once and fix it to last for many years. TexasHonda has good suggestions on what to do.