Trying to educate myself on A/C maintenance.

My A/C works. However, I believe I hear what sounds like a bearing noise when the A/C clutch pulls in. Sounds sort of like a throw-out bearing noise you hear in a M/T when it is about to go out, in case you are familiar with that sound. It is not excessive, but it is noticeable enough to make me read a bit on A/C systems. This happens when the A/C clutch pulls in only.

I found several references (using google) which suggest that lubricant for the A/C, or more correctly, lack of proper lubrication, is a primary cause of compressor failure. That is basically where I am now.

So how is lubrication done? There appear to be several likely possibilities. Some port on the compressor, or maybe an injection of a special oil when the refrigerant gas is changed?

Can anyone take me a bit further with how lubrication of the compressor is done?

Thanks for any info.

 

The refrigerant gas has a lubricant in it and this should be enough. If the AC has not been used much moving parts may have dried out. This happens a lot in the UK as we don't get enough warm weather to need the AC running on a regular basis. Owners do not realise the AC should be run at regular intervals,regardless of the weather,to keep everything lubed.

 

I don't recall lubricating AC compressor even though there might be possibilities. If they are bad, people just replace them.
If you run AC regularly, AC systems can hardly go wrong.

Since your AC works, then you are good to go.

It's good to run your AC even during the cold weather.

 

Thanks for the info guys... billofdurham and volvolove. That makes sense. I'll ignore the "mild" bearing noise, and, if it gets to be loud enough to be of concern, I'll replace the compressor and recharge the system. In the meantime the system works.

I'm a Toyota person by experience, as I need reliable 4wd 4-5 times a year, so I have a 4Runner and a long bed PU. Both are very easy to maintain. But I'm enjoying the "Volvo Experience". Main differences I've noticed are Volvo's emphasis on safety (you notice little things that make a difference in their emphasis), and, on the downside, Toyota is really good at body hardware, switches always work, plastic is bulletproof etc, whereas Volvo is terrible (based on my experience and reading others experience) with plastic and switch reliability. Other things, it is easy to get parts for Toyotas in the rare case you need them, but much more difficult for the Volvo, especially in the case of my Turbo Diesel.

But this Volvo loves to cruise at 80, gets amazing fuel mileage, is very "solid", and feels very "safe"..

Different worlds. But I think Volvos make a lot of sense, all things considered.

 

yeah, volvos have lots of electrical problems as it turns out and parts are expensive and difficult to get.
so do bmw, mercedez, VW, audi, etc.

 

rdharper, i would not recommend to ignore that noise. What I would recommend is to check/recharge your AC with one can of 134acontaining oil. People make the mistake of just recharging their AC without adding any oil, thus killing their compressors. I believe that recharging the system is less expensive than installing new compressor.
P.S. One of my "ex" mechanic told me my compressor was bad.... until I recharged the system with one can containing oil andthe "bad compressor fix itself...."

 

Thanks for the comment. I've been following the previous advice of leaving it running... which has resulted in the system becoming more quiet.

However your approach makes sense. I was not aware that you could add "a can". The valve must allow that... or is there a "trick"? I'd assumed once you went for a refill, you had to completely discharge the thing... then recharge from that point.

Secondly, I was also not aware (thats a lot of not-awares) that you could buy a can with lubricant in the proper ratio for the can.

Any further tips would be appreciated.

 

yes you can buy a canof refrigerant with oil.
1. check the system's pressure by allowing theAC to run for 5 minset to max cold using the AC recharge pressure gage set.
2.if the low side pressure is below 35 psi, add one can. (depending on your car and outside temp, you should avoid going over 45 psi)
3.enjoye your cold AC.

 

Thank again for the info. The '84 (the vehicle in question) has no markings indicating conversion to r134a. I understand the low-pressure fittings are physically different. Anyone know how to spot them?

I see r12, while not legal in California, continues to be available. I've never heard of anyone being prosecuted. I don't think it is illegal to own, only to purshase. (ain't that cute).

Do all cans, r12 or r134a, contain oil, or does it have to be specifically marked as containing lubricant?

Addendum: Here is a URL for an eBay kit which claims to handle both r12 and r134a systems. I'm going to give it a try. Thanks again for all the help you guys.

http://cgi.ebay.com/ebaymotors/R12-F...QQcmdZViewItem

 

Follow up on A/C adventures. The kit I referenced in the previous post worked!! The guy that did the kit provided a video which explained the whole procedure... extremely well done.

My Volvo is now a refrigerator. I know how to keep it that way. I'm a happy camper.

Oh, and the bearing noise is gone.... thanks to the supplied oil.

Lastly, thanks for the help you all... it helped!!

Addendum: One tip. If your A/C is "working", but weak... and the clutch is cycling the compressor at regular fairly short intervals, that is a sure tip that the fix is simple. What happens is... if the pressure is below a certain level (about 25lbs), the compressor will drop out (there is an in-line switch)... build the pressure, then engage. Pressure drops in a short time... too low, compressor is shut off... cycle repeats.

That simple case you can fix yourself... in about 15 minutes, with a "kit". If your system ever needs another treatment, the cost is peanuts.

 

I'm glad that everything worked out for you.

 

Thanks again pawel, your input kind of pushed me into finishing the job. I ended up using R12a since the kit came with adaptors and the excellent video. Plus R12a mixes with either R12 or R134a. So I can use it on my 4Runner as well.

I researched the question of the use of R12a. As you know, it is a mix of hydrocarbons which are flammable. But it is a better coolant than R12 (freon). R12a was the original coolant used at the turn of the century. It was abandoned because of the stability of Freon. So there are a lot of hystryonics on the web about R12a. However in the quantities used, and the way it is used, you would have to have a very unusual combination of events to create a fire or explosion. Even with a leak, it would dump on the ground below.... in an open environement the risk is very low, even if the whole 3.5lbs dumped instantly.

Couple that with the fact that no cases of fire happening have ever been documented... the risk is acceptable. After all, gas and diesel to a lessor extent are potentially hazardous. And there are a lot of vehicles running propane. Its just a silly smokescreen to worry about R12a.

That coupled with the ease of use, and more efficient as a transfer gas... I'm in.

I'm a worry wart... one of the reasons I prefer diesel is its lower volatility and higher flash point. If R12a meets my level of concern... its safe.

I added one can of R12a and one can of lubricant... which is meant to provide the right lubricant in the right quantitiy for 3.5lbs.. I assumed mine had never had any added. The "expert" on the video said he adds one can for every two cans of R12a. Anyway, it sounds good, works well at this point.

Thanks again.