runyun

Hey guys..

So I go and buy the recharge kit from Autozone ($35) and I prepare to recharge my AC.

Symptom:
Air does not blow nearly as cold as before. Some times it doesn't even get cool.

Recharging process:
I read up and prepare to do the recharging. I start the car w/ AC level 4 for 10 minutes. I then check the pressure on the LOW pipe. It reads 25-26 lbs.

My question is:
1. Does the R134 gas ever become "bad"
2. Do I let out the current gas and refill it with the new can?

Obviously this is my first shot at this - couldn't find a topic when I performed a search on this...

Thanks again

njmaxseltd

iTrader: (19)

1) No
2) No

Scruit

Do not discharge the existing R134a. Put the oil charge in first then the R134a. If you charge it up to much then the compressor will be turned off by a safety mechanism that senses the system pressure is too high.

The best way to figure out what is going on with the A/C is to run the car up to normal temp, open the windows, turn the A/C on, pop the hood then go look at the compressor. You can see if the clutch on the A/C compressor is turning. (at the bottom of the front of the engine, passenger side). If the clutch is not turning the the A/C is not running, either because the system pressure is too high (overcharged), the system pressure is too low (undercharged) or the car's interior is already cold enough (you got auto climate or manual?

The existing R134a charge can become 'bad' in a manner of speaking, meaning the system can become contaminated by moisture if there is a leak. if your system pressure is low then try just recharging.

If, when you're done with the recharge kit following all instructions carefully, and the A/C clutch is erngaged and is running the compressor properly, and the charge level is ok (the charge level can only be read when the compressor is running the air is just not cool enough, then you have to get into more indepth diagnosis that you would need to get a book on automotive A/C from the library or take it to a mechanic/dealer. If the compressor refuses to run then you can be overcharged or undercharged and that is difficult to diagnose with the recharge kit.

Be careful not to overcharge it. On my truck after doing the recharge the system quit running and I actually unplugged the high pressure sensor and jumpered it to see if the compressor would kick in - it did, and the guage showed I'd overcharged it. If the compressor didn't kick in then it could have either been a problem with the hi-pressure sensor wiring (unlikely) or undercharged, so charging a bit more would have fixed it.

runyun

njmaxseltd,
thanks for the short and sweet reply

Scruit,
The pressure was around 26-27lbs.
So since the pressure was pretty strong, I'm guessing there wasn't any leaks? (unless thats still possible)

I'll check to see if the "clutch" is spinning. I'm guessing it would be something obvious to see.

Manual

I can't. The kit I bought has the oil/R134 all in one can.

So I'll go check the clutch on the compressor. If it's not spinning - replace? My problem is that when it does cool.. the air is not nearly as cold as it should be. Maybe the compressor is going bad?

How is the Hayne's manual. I really do need to invest in a good manual.

Thanks Scruit

Scruit

A/C compressor replacement is very expensive, so you'll need to do a lot of diagnosis before you do that. Main thing to watch for is that the compressor is actually running. It's easy to see because the outside of the pulley will either be turning with the belt or not. The A/C does naturally cycle on/off but cycles very slowly, like minutes.

If you have the oil/r134a in one can then use that can first. Early kits had one can of oil (sometimes oil/r134a) and a couple of cans of just r134a. Always use the oil can first.

runyun

Thanks again.

UncleMax98

What is the correct AC compressor oil for 98 Maxima? I went to Autozone and saw many different types of oils, e.g. ester, PAG 46, PAG 100, etc.

Note: I am the newbie UncleMax, not the veterant "Uncle Max"

Dave Holmes

May not be your problem, but worth checking.
On my '96 GXE, the passenger side cooling fan stopped working. The AC was warm, but pressure, compressor, etc... all checked out fine. I then learned that the passenger side cooling fan should be on at all times the AC is on. Replaced the fan, and it went back normal. When I had this problem, AC was cold as long as I was at highway speeds. Stopping at a light, the AC would be blowing outside temp air.
Also note that anytime the passenger side fan is on, so should the driver's side. The driver's side is the primary cooling fan for the radiator. The passenger side is the secondary. Even with the secondary fan not working, there were no engine cooling problems running this way for a month (I checked with Nissan about it prior to running it that long. They said it would be fine). This was in Louisiana July-August temps (triple digits).

Dave

runyun

thanks Dave for the heads up. I'll ck the fans too.

didn't get a chance to look at the clutch yesterday since i took the maxima into the dealer for an oil change.

rofl, before i get flamed... this past weekend i changed out a starter on the suv, swapped out the bad ecu in my max (after pulling it from a junkyard).. and did yard work (in hot texas weather)

i found a coupon online for a local nissan dealer that offered a $19.99 oil change.

figured the OEM filter would run about $8-9.. then the oil about $6. So I figured the extra few bucks would be worth my time from getting under the car and away from the heat!