Okay, I just installed a new compressor (OE). I was told by a guy at the auto store that usually a new compressor already comes with enough pag oil inside so there is no need to put more oil in. Is this true? I'm going to vacuum that thing, is vacuuming going to take those oils out? Also, how many 12ozs cans of freon should I get? What's the capacity of our R134a system? 60oz? Should I install more oils, if yes, how many oz is needed?

Dang, I did this a few years ago and I cant even remember, I believe it was like 2.5 to 3 cans.. it should say under the hood what the capacity is, check and get back to us

The system takes 1.98 plus or minus .11 pounds of R-134a and up to 6.8 ounces of oil. So adding two pounds should be okay.

According to the FSM, there should be some oil coming out when evacuating the system and it should be recorded along with the amount that came out of the compressor drain hole. Then drain the oil of the new compressor to see how much more oil will be needed to be added into the system. Then put back the new oil along with the extra needed oil.

Also, just in case, read the compressor warranty. Some may claim that you will need to get a new dryer too or the warranty will be void if the compressor were to fail without replacing it.

Might as well get a new dryer anyway. No reason not to for a ~$20 part. I replace the dryer any time I open an a/c system. You don't really "have" to unless the a/c system is open for a few days, but seeing as they're not much money, I always do anyway.

$40 for 92+ last I checked

I paid nearly $87 for it at Courtesy . But it includes the dual pressure switch which I intended to replace too. Not sure if it's included on aftermarket dryers.

$10.89 - $20.79 at Rock Auto for the dryer depending on the year..

yo yo I got these bad boys:





The blue line is connected to low pressure.
The red to high pressure
The yellow line goes to the pump. What I don't get is at the gauge set yellow line input is a T connector. I'm pretty sure one side goes to the pump, but what about the other side on that T? Does it need to be connected to anything? Also, the pump doesn't have an outlet to drop the receiving oil. Any idea where it could be going to?

Any ideas as to how I should I use this thing? I've never done this before so I want to learn this once.

The T is to purge the line. Your refrigerant goes through the yellow line so you purge it of air first, so that you don't suck a bunch of air into the system after you just vacuumed it



The oil doesn't go into the pump, it goes directly into your A/C system. Not sure on the Maxima, but I know on my Civic I put a few oz. in the compressor itself, and then an oz or two in the condensor, and then usually an oz or two goes in the dryer.

Funny I have that exact gauge set and vacuum pump. The gauge set is pretty cheap, but the pump works well (even though it sounds a bit anemic).

You probably want to do some research on using the gauges. I'm no expert on using the gauges so I won't try to explain, too many variables.

Few cars are ever over 8 oz. you are better off with too little than too much

8oz? Nah, you're thinking about the new European replacement for R134a, I forgot what they're called... but tree huggers are blaming R134a damaging our ozone so they're getting it done.

Okay guys, I got it done. Took me an hour. I vacuumed the system for 35mins.

Result: 30 PSI (low) & 190 PSI (high). The compressor operates extremely quiet. I can't even tell when the clutch is engaged unless I put my ear right next to the compressor. Wow, nice nice.

New Parts Changed: Evaporator ($45), Compressor ($100), O-ring kit ($8), and Dryer ($17).

Regarding the capacity, it took me 2 cans of 12oz refrigerant ($13) and 1 can of 3oz oil ($4). I should've not press in that 3 oz of oil. What a waste of money, now I'm definitely sure my compressor was already fully loaded with PAG oil.

Refrigerant, Oil, AC Gauge Set, & 2.5cfm pump cost me $150 total. Not bad, I like the fact that I get to own the tools.

That's what they said about r12 too

anyone knows what is that tard looking smelly crap that Nissan wrapped around the orifice that attached to the evaporator core? I didn't know where to get that item so when I changed my evap core, I just reuse it and man that thing is annoying as hell. When it gets a little too hot, it melts and produces road tardy odor. I swore, it stinks...is there a chemical out there that I can use to neutralize it?

It's called prestite tape (I think that may be a brand name?). It's meant to insulate the bulb portion of the expansion valve from the ambient air around it. That way, it measures the refrigerant temp as it leaves the evaporator rather than the air around it. Also, it keeps condensation from dripping down and soaking the floor/whatever

Odd that it's giving you such an odor. I've never had such a strong odor before, especially on stuff you've re-used. Why would it be getting so hot as to produce a tar-like smell? Did you heat it up to wrap/press it? Even if so, it shouldn't STAY smelling like tar after it cools off

Hmm is the A/C going out a common Nissan problem, mine is out too damnit...

Actually, 3rd gens have pretty stout/long lasting/trouble free factory A/C systems. You really don't see many A/C complaints/problems among 3rd gens. I see 4th gen A/C threads ALL THE TIME. Nissan really went cheap with the 4th gen.

Not sure about other Nissan's though..

My 05 Altima SER only has 49k on it and the A/C recently went out hopefull all I need is a recharge and not a expensive Compressor

They're about 1cm thick tape, black, with sticky tardy gooey. When it gets hot, they'll release that tardy smell. Man, I wished I had known where I can get the prestite tape before hand. I wouldn't have to deal with it right now. But it's too late, I guess I have to live with that smell for now. Oh well. It's probably did that because it's old. I dunno, just guessing.

I wouldn't mind upgrading from R12 to R134.....I'll check to see what's involved!

Retrofitting an r12 system to r134a isn't really an upgrade. A retrofitted system generally doesn't even work as well, let alone better. Although, depending on the car/condenser design, it can work well enough that you don't notice a large dropoff in cooling ability. Just FYI

So converting over from R12 to Onethirtyfour a is a waste of time yah think. I ask cause I need to recharge my r12 system and freon is hard to get/expensive. I was gonna either convert or just put one thirty four a in my r12 system. Any opinion on that?

http://www.freeze12.com/
try it, let us know how it works?

Not sure if it's a good thing to do, but mine was working just fine for years after someone snuck r134a into my r12 system.



True.. My 03' BMW at 105k was already having A/C trouble. Thats when I bought it. Who knows when it originally started. And nobody can find where its leaking from. Even better. I've never had A/C trouble with any high mileage 3rd gen I've owned over the years.

My 286k at that time (now 332k) 4th gen had working A/C when I got it with the exception of an o-ring slowly leaking, perhaps I got lucky?

My 3rd gen I had to replace the condenser before I could get cold air and currently isn't working because of a wrong size o-ring that couldn't hold pressure by the condenser, otherwise I'd say they both do have great A/C systems

On my max, the bolt holding the low pressure hose to the compressor was rusted as well on the inner thread of the compressor which caused a very large leak. Instead of fixing it, I might as well convert everything from R-12 to R-134a. Got used evaporator compressor, condenser, lines and hoses from a donor 94. So far it's working well and it's operating much quieter than the setup it had.

That's the way to do it right if you're gonna go r134a. Can't really beat going with a factory setup. '93-94 Maxima's were all factory r134a

Does putting r134a into an r12 system ruin seals or something?

It can cause a chemical reaction. So, yes and not only that but ruin every componet of the system.

Yeah, it'll kill your compressor quick. Plus r134a and mineral oil don't mix

yea mineral oil is something more like what you'd wanna shower in or rub on your face to look young and beautiful

Some body replied to my post on the topic of putting r134a into r12 system and suggested this freeze 12 stuff that is the same thing as r12. It read that it would work with my r12 system the same.

Freeze 12 is actually 80%+ r134a.. The rest is 142b which supposedly helps carry the mineral oil through the system to lubricate it (r134a won't)..

From what I understand, it doesn't work nearly as well as r12, and probably not even as well as a properly retrofitted r134a conversion. Most experts I've seen on some A/C forums really don't recommend it

bvtran... what kind of center vent temps are you getting at idle with the r134a (as well as the outside temp at the time)?

I generally despise r134a but it seems the 3rd gen has a stout enough system to handle the conversion well. My "new" '92 keeps losing its charge so I'm contemplating which direction I want to go with it. My '89 Civic has such a rinky dink little A/C system that I was getting 70+ center vent temps when I retrofitted it to r134a, hence my move back to r12.

Holy moly! thats not considered A/C, thats like a fan I remember when I first got my 3rd gens A/C working, I was getting like 24-30 degrees Fahrenheit with about 80-85 ambient temp, 'twas awesome. My 4th gen's isn't as freezing cold but enough to make you open the window a bit or lower the AC