Air con pump advice

kyles1976, Sep 19, 7:42am
Hi some advice. My air con pump in my Mazda 6 failed 5 months ago and I a second hand one was fitted by an air con specialist. The 2nd hand air con unit was under a 3 month warranty and then 5 months later the compressor failed and now I have to get another unit fitted!Costing me another small fortune. What I want to know is whether the compressor could have failed because it was already faulty and have I got any legal rights even though the warranty period was out by a couple of months! Any advice would be much appreciated!

intrade, Sep 19, 7:53am
could be that the actaul fault nuked the unit, it be hard to proof , you probably want to find a place whom is better at what they do. My mate who knew loads about aircon has died 2 month ago so cant ask him no more what he knows. But i remember the dryer should always be changed. check your paperwork if that was done last time round.

mantagsi, Sep 19, 7:54am
I work in the refrigeration industry, and we have a bit of folk wisdom for these situations - compressors don't fail as a rule, a failed compressor is almost always symptomatic of a problem elsewhere in the system. I would get a second opinion at another car air conditioner firm and see what they say. When you say it is broken, can you provide any more specific details!

kyles1976, Sep 19, 8:15am
Hi there thanks for the advice.Apparently the compressor collapsed. It started with a funny rattlingnoise and over the day it gradually got louder. When I drove it to the garage today the air vent was literally smelling of a foul and very strong burning smell.

4piggy, Sep 19, 8:29am
was the ac system flushed and new tx valve and drier fitted when job was done also did it fail due to running low on gas from leaking evaporator(common fault on these vehicles) or tx valve failing,job may not have been done fully causing new unit to fail as its not common for these pumps to fail, ive done plenty of evaporators and a few tx valves but never a pump on one

kyles1976, Sep 19, 9:05am
hi there thanks for your feedback. They didn't go into specifics and I guess I will never know cause we put our faith in the fact that they should know what they're doing! I will definitely ask the mechanic who passed the message on for more information.

mantagsi, Sep 19, 9:07am
Hmm, sounds a bit nasty. I am no guru on automotive air con, but I do know that sometimes folks can retrofit a new refrigerant into old systems, and you can have issues with the new refrigerant not carrying oil properly, which can affect the compressor. Being a Mazda 6 I would imagine it is a pretty standard R134A system, not some old R12 setup with a goofy drop-in refrigerant.

My best advice would be to try another auto ac shop. If I were doing it myself for example, I would recover and dispose of the old refrigerant & oil, clean the condensor & evaporator, flush out the system with a good cleaner (pity R11 is banned!), then vac it out, bang a new filter drier & new compressor and charge virgin refrigerant and correct type/volume of oil. If it failed again I would definately start to wonder what on earth is going on!

kyles1976, Sep 19, 9:20am
Hmmm you realize it is a female you are talking too! :) problem is its at the garage now and I can't drive it anywhere cause of the smoking issue! The air con guy is doing another second hand air con unit for me at half the price of the first one but adding it all up I should hav just bought a brand new air con unit in the first place! Thanks for your advice, I'm going to use these suggestions and speak to the mechanic tomorrow:)

mugenb20b, Sep 19, 9:24am
After reading about the A/C problem, my guess is that the replacement compressor has had its oil drained out and fitted "dry" or a clutch bearing collapsed, which can happen.

kyles1976, Sep 19, 9:28am
hi there, so you think if that is the case then they didn't do their job properly! Is there anything that an owner/driver could have done to have caused this to happen!

mugenb20b, Sep 19, 9:42am
I'm only guessing here based on what I've read.

But, this could be one possibility: A/C compressor supplier *may have* drained the oil out of the compressor. The fridgie may not have checked that there was any oil in there when he bought / fitted the compressor.

The compressor may have been left open on the shelf too long (moisture contamination) and therefore failed prematurely. Brand new compressors are usually precharged with Nitrogen so that no air can get in.

If the above fault occured, it will be just about impossible to prove who or what was at fault. It may be a combination of things.

The other problem, clutch bearing, it can fail at any time, that's just bad luck. The burning smell may have been the rubber belt slipping, squealing, smoking, etc. Who knows, you'll find out tomorrow.

mantagsi, Sep 19, 9:45am
Yep :) I work with a lot of very smart technically inclined women, they have trained me to never speak down to them on pain of death! :P Good luck anyhow, I hope it works out for you in the end

cuda.340, Sep 19, 10:05am
when you pick your car up, ask to see the old compressor. when they show it to you, ask that they drain a little of the oil out of the compressor so you can inspect it. if it is clear like water, the oil is good. if it is dark, & the darker it is the worse it is, then confirm they have fitted a new dryer into the system. a dryer looks like a cylinder with two pipes attacached at the top. usually this also doubles as a sightglass to check the refrigerant level in the system. if no oil comes out then you have your smoking gun for this failure. if the oil is dark that could most likely be due to contamination prior to being fitted last time, another smoking gun.

4piggy, Sep 20, 12:19pm
these cars dont have a drier as such they have a drier bag in the side of condenser and have no sight glass as most newer cars dont, if she wants to find out cause of second failure it would be best for her to take old compressor to another ac specialist and have compressor stripped to find out what caused fault as if oil is dark it doesnt prove it was contaminated from before it only proves that compressor is stuffed now and when compressor is stripped the cause of failure can normally be found

pup2, Sep 20, 6:54pm
I always go for the overhaul or new unit option. 2nd hand means you are buying someone else's problems (as in the compressor may have been working on an undercharged or contaminated system). Air con is not cheap! Motto is.do it once & do it right.

lyonruge, Sep 20, 7:14pm
As said before, the pump possibly failed due to contaminants in the system, the system should be cleaned out and a new receiver dryer fitted when the first pump was replaced. They should have advised you of this at the time. If it isnt done again this time, give it about the same time and save up for another pump, this one will die soon too!