Checking refrigerant level - '02 Accord

I'm afraid the sight glass and recharging by guage went out with R12. The experts say R134a has to be charged by evacuating and putting the correct weight of refrigerant in.

If you weren't using the defroster often in the winter the seals may have lost their oil and leaked some refrigerant out, but whether the charge is correct now and whether the system is leaking now only a pro with the actual service machine can tell you. (Well, once the system is emptied you can do your own evacuation and leak test if you have a refrigeration pump, and I suppose you can get a larger than correct canister and use a scale to tell you when you had transferred the specified charge.) I did all my own A/C work in the days of R12, but now I just don't have the equipment to do a competent job. Any auto parts store will sell you stuff to do an incompetent job.

In an '02 you don't want to start doing the stop-leak bandaid. Wait until the car is at least 10 years old before dropping to that level of service.

Finally, verify the temperature control cable adjustments. If the mix door is still adding heated air or if the control valve isn't closing off the air will never get cold.

Mike

Could you explain the need to evacuate? Why couldn't you just add refrigerant until you have the right pressures, thereby replacing what has leaked out over the years?

Not an expert, just parroting what the guys who claim to be: R134a can't be filled by pressures. (Actually, R12 could only marginally be done by pressures - my former boss was a refrigeration man in a prior life and he could do it by filling until he felt liquid in the compressor return line and then venting until it stopped. I tried to feel what he was describing gut I couldn't tell. He could estimate the pressures based on the outside temperature and humidity but never relied on them.) Apparently the pressures with R134a are only a measure of condensor and evaporator temperatures and don't relate in any useful way to the amount of refrigerant, like pressure in a propane tank only tells the temperature and not the amount of propane inside.

I've tried to fill R134a by pressure and only succeeded in messing things up, so there must be something to it.

Mike

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Have you changed your cabin filter(s yet? If they're plugged, you'll only move about 1/2 as much air thru the system as you should, whether on RECIRC or regular.

'Curly'

Yup, that actually _is_ something I did on my own since I didn't want to pay the dealer $109 for the labor disassembling virtually everything on the front-passenger side under the glove compartment.

Airflow has never been a problem. However, ever since the car was new the air coming out of the vents (with A/C and RECIRC both off and with the temperature dial all the way to Cold) always was slightly warmer than the outside air. I assumed it was unavoidable that any incoming air would pick up some heat from the heater core - my '92 was the same way. In any case, the difference in A/C performance when I'm at freeway speeds versus sitting idle at stoplights is much more obvious lately. That difference was only slight in previous years.

Mostly, that sounds like the compressor is going bad. The valve plates leak and otherwise don't perform well, and that effect is minimized when the the engine is turning faster. An '02 sounds awfully new for that, though - usually it takes about 10 years to reach that point.

Another possibility is that the condensor fan has quit. The airflow on the road takes over to make the fan unimportant while cruising. The fan is something you can check yourself, while the bad compressor is a conclusion even the experts reach when everything else checks out okay.

If the refrigerant is low, the cooling is the same at idle as at speed, but the compressor cycles more often at speed than at idle.

Mike

More details: if the compressor is in fact going bad, is it possible that visible "vapor" coming out of the inside vents is a symptom of that failure? It rarely happens, but at 26K miles I reported this to the dealer during a routine maintenance visit (it was documented but they couldn't find a problem at the time). So there is a chance I could get this fixed under warranty since I reported it early on, even though the warranty has since expired. Compressor fan is OK.

Lemme correct that last sentence - condensor fan is OK. Tells you how much I know about A/C....