I bought the car new and have never had a problem with the AC cooling until late last summer when apparently a small leak developed that required adding one pound of R-134A. So I had it topped off and everything seemed fine until about 3 months ago when the AC started blowing warm air again. The compressor spins freely. My mechanic checked the system to see if it was low on freon again and it was full - but the pressure on the gauge was high.

The mechanic said it looks like the AC system has a blockage somewhere. He told me to get a quote on a compressor kit, which I did. Do you guys agree it sounds like an AC system blockage and does this mean the compressor needs to be replaced? Or is it common in these cars to develop an AC blockage in a particular place in the system?

Does anyone in the group have any advice?

I’ve owned my ‘99 since brand new as well.

Since then my AC system work has pretty much been the equivalent to 2 full system replacements … with much of the hard-part replacement work having been done by me.

My advice would be to find a reputable auto AC shop in your area and have the system evaluated by them, being prepared to have pretty everything replaced.

Compressors, accumulators, evaporators, refrigerant lines, can all be replaced DIY. It’s time consuming but totally doable, if you’re so inclined, but then with the system being charged and balanced by the pros (assuming you’re not).

That’s my advice …

I don't know what to recommend or how to respond, because I never heard the term "Blocked" in an AC system. But maybe that's a possibility with too much leak stop.

I'm with TB.... Second opinion at a REPUTABLE AC shop. My 99 is all original with 218K.

A blockage in an a/c system comes from a failed component typically an old compressor will ware internally and fill the system in time with tiny participles of metal, this is why flushing the a/c system is critical

I will attempt to explain this some what, Ill assume your mechanic hooked this up to an a/c machine and is seeing a higher low side pressure. What were they? Was there any movement in the gauges when the compressor kicked on? There could be several reasons for this but some things will need to be verified first. Is the compressor on and turning and are the fans running on high.?
The system it self is actually not complex, we replace most a/c systems in kits these days in the shop because that how's they are sold to us for warranty purposes.

Did you ever find out where it actually was leaking at the first time.? If you added Freon back then hopefully it contained dye, did he check this with the light.? what I typically find on Nissan is the compressor's leak at the case half's just under the car. If you want to replace the majors if that's what determined here you mainly need a Compressor, Expansion valve and Dryer. I also recommend replacing the evap core while you have it out. The expansion valve is attached to it on these behind the glove back. Everything else can be flushed. IMO Id'e buy a used OEM compressor they are still in fact superior to what is out here aftermarket for Nissan today.

I have gone through the pain and suffering of a faulty AC in my Maxima. I live in an area where summer temperatures reach 100 degrees. So a functional AC is a necessity.

I took my car to 2 garages. The 1st garage gave me a quote for $2500 to replace all major components. The second garage said …sure they can fix it. But after driving it back and forth for weeks for them to look for leaks, I realize they have no idea what they are talking about.

So I took matters in my own hands. AC’s seem complicated but they really are not. My 1st advice if you are a DIY is get an AC manifold pressure gauge with high and low connections. By measuring the pressure on the high vs low end, it will tell you many things about your AC.

My testing led me to a faulty compressor. I went ahead replaced the compressor and the condenser. It cost me about $350 in supplies and a couple of days in me garage. That was in 2019. Four years later, my AC still blows 35 degree ice cold air when it is 90 degrees outside. Awesome feeling.

If you can fix your own brakes, you can tackle an AC job - IMO. It just takes a bit of learning because it is not something that we have to deal with very often.

Which brand of compressor and condenser did you replace it with?

It has been almost 5 years since I did my repair. Unfortunately, the brands of compressor & condenser are no longer available. But here is a link to the compressor that I used:


If you search amazon, there are plenty of other options.

I spoke to this guy a couple of years ago when I was trying to replace the clutch pulley bearing on my 99 Maxima.

Good guy... Knows his stuff, and he's straight forward. He can help you decide what's REALLY necessary to rebuild it right and to last MANY years without wasting money..

https://www.ackits.com/