A/C Compressor is leaking after repair shop…

[qx4guy333]

Hello, I have a 1998 Infiniti QX4 3.3 liter engine. I took my SUV into the shop to have the timing belt changed. They had to disconnect an A/C line that was in the way of the timing belt cover. When they were done they said they did an evac/recharge. The day it came back there were green drips under the compressor, which got progressively worse, and now (couple weeks later) the A/C is not blowing cold at all. I took a look at the A/C line that they disconnected and I didn’t see any green leaks at the connections. All the drips are coming from underneath the compressor. Do you think they could have caused this or do you think it’s just a coincidence? The A/C was working fine for over a year until the day they touched the car. Everything (and I mean everything) in the A/C system was replaced a year ago except the compressor.

Someone suggested that I take the SUV in for a UV test thinking it’s the little o-ring seal where they disconnected the line, so I did. They found it is not the line or the o-ring seal, but that the compressor is leaking. My question is do you think they overcharged the system and this is what caused the compressor to leak? According to the instructions that come with a compressor it says, "Compressor failure can occur because too much refrigerant causes high head pressure which will destroy the compressor." Do you think the guys who did the repair job put too much refrigerant? Is it even possible? Isn’t there some kind of safety built in that would prevent them from adding too much refrigerant (1998 Infiniti QX4)? It's the only thing I can think of that they might have done wrong, but I don't know enough to make this conclusion. Do you think it's just a coincidence instead?

The guy seems really honest so I would hate to accuse him, but I also don’t want to get stuck with a bill all because they did something to make my compressor suddenly leak.

Thanks in advance for your help; I really do appreciate your time.

[qship96]

It is possible they overfilled the system which would cause pressures to be high enough to blow open the safety valve on compressor causing the leak you are seeing and lack of cooling. It is possible the evac/recharge could have also finally caused a weak seal in compressor to go-

if compressor is original to car{ 11 years old} it is time to replace it with new, as it is past normal lifespan- replacing compressor now, before it fails and spews its guts throughout every other new component you have replaced in system is easier and much less expensive than waiting for the day it locks up and grenades.

[SteveTheTech]

Great advice Qship.

While this could be a bi-product of age without a doubt. If they added more oil into the system that could have damaged the compressor, or over charged it by a few pounds could cause the pressure relief valve to blow.Both of these incidents have only one repair, complete compressor replacement. Cleaning is very often overlooked but it is crucial to keeping older parts working for as long as possible. Depending on where the oil on the compressor is coming from would be a stronger indication but the way oil travels would make it nothing more than a guess even at any point . Many shops will make a deal with you either on the part or labor if something like that happens with a system that they took apart. It's just a hazard of the business. If the guy seems honest enough he should be willing to "give" a little, don't expect to get a free AC compressor but getting something off either the labor cost or parts would be a concession to save face.

[maxnix]

STT, is it SOP to open the AC to repair the timing belt on these 3.3L V6?

[SteveTheTech]

STT, is it SOP to open the AC to repair the timing belt on these 3.3L V6?

Not from my experience. Why do more work than is needed? Especially opening a system full of hydroscopic oil.

The tube can be moved out of the way with little effort once the mounting bracket bolts are removed. Oh well live and learn.

[maxnix]

Hence there is a question of competence here.

[qx4guy333]

Thank you everyone for all of your replies!

I had one quick question, do these compressors even have a safety valve that blows open if the system is overcharged? About how many pounds of overfill would it take to blow it? Is there something I could look at on the old compressor that would tell me if they did this? I would hate to confront the guy for nothing, he seems so honest. Although, everything was working fine until he did the evac/recharge.

[qship96]

The Q45 compressors have a pressure blow off valve on bottom of housing, probobly spring loaded. Since the Q compressor is nothing special or unusual, I would assume all nissan{and others} are similar- look in the factory service manual for confirmation.

[SteveTheTech]

There really isn't anyway to be able to determine the cause of failure of an AC compressor. I'll see what I can dig up and I will update when and if I find a decent picture of the valve in question.