Air conditening question!!!

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After how many years would you expect your vechiles air conditening unit to loose enough of it's charge to make the compresser not kick in anymore? My Civic is 9 years old and after a few hundred miles of driving in the heat with the AC on it blows only warm air anymore and the compresser does not kick in. Do AC unit's need to be regulerly topped off?? I mean no AC system can possibly be 100% tight right???
 
In a perfect world the system should stay charged forever. Every car is different so there is no way of predicting how low yours may be.

But since yours works then quits when things warm up I'd look into a wide clutch gap that expands when things heat up.
 
No Chris the AC stopped working after i used it for several hundred miles. Its not kicking in any longer. Before the long drive I had no issues with the AC!? My freind says that the refridgerant level is probably too low and thats why the compresser wont run. Should I try having the AC recharged or should I have them look for a leek allready???
 
If it's low it will cycle on and off, on and off. Next time it doesn't come on tap the clutch hub with a screwdriver and see if it comes on

If it was so low that it can't come on it won't come on at all.

Yours works ok till things heat up so it has enough refrigerant to work.
 
It could be any number of things. Low refrigerant is one, bad clutch is another...or bad hi/low pressure switch, blockage in the system, bad relay, bad compressor, bad HVAC control unit, etc. If you jump the clutch pins, does the compressor come on?

If you've never worked on an A/C system, I'd leave this one up to someone with the proper tools and some experience to troubleshoot it.
 
Just to give you an idea my 91 mitsu has only had one can of R-12 added in all the years I've owned it. I put a can in last summer after checking its pressures. Going by temperature and pressure it seemed to be low. Adding a can didn't help or hurt, pressures stayed about the same and the vent temp didn't go much lower than the 43F it was before on a HOT day. So I'm guessing its probably a compressor getting a little weak. It has held its charge right at 18 years and still cools pretty well so I'm gonna leave it as is until it develops a real problem.

To answer your question further I've seen cars loose their charge after only a week (stone hit on condenser) and I've probably seen many go 10 years. I'd have to guess most fall somewhere in between those at 4-6 years without problems.

I'll give this one tip. If you get it fixed or have a car that it does work properly USE IT once a month for about 5 min even in the winter. A lot of newer cars run it in the defrost setting so its getting hard to not use it sorta year round. I've heard it helps keep o-rings "wet" with oil and will help keep the system sealed. I tend to belive it now.
 
Originally Posted By: Oilpants
After how many years would you expect your vechiles air conditening unit to loose enough of it's charge to make the compresser not kick in anymore? My Civic is 9 years old and after a few hundred miles of driving in the heat with the AC on it blows only warm air anymore and the compresser does not kick in. Do AC unit's need to be regulerly topped off?? I mean no AC system can possibly be 100% tight right???


Both of the Cavaliers my aunt had didn't make it through 2 summers before the system leaked out all the refrigerant. She had it fixed under warranty and they both leaked it all out again... So 9 years isn't terrible.

My sisters 2000 Elantra which has over 300K KM (180K Miles) still has ice cold A/C in it and has had nothing done to it.

IME, most "Domestic" vehicles seem to have more A/C woes then that of other makes, with the exclusion of Ford. For some reason...
 
Any R134a system since the mid to late 90's shouldn't lose refrigerant. If you're losing refrigerant, there's a leak. In days of yore...R12 systems seemed to gradually discharge over time.
 
Ford testing shows an average of 7 ounces a year loss of refrigerant. Seems high to me, but it shows loss is normal.
Leaks at junctions,the compressor seal, and even right through the rubber lines accounts for this.
So after 9 years, you are long overdue for a shot of fresh refrigerant.
 
You don't need a mechanic to check the pressure. Get a gauge/filler and add a pound or 2 if it is low. Use the high mileage R134a with oil and seal conditioners. If it is actually empty (at atmospheric pressure) you need to vacuum/evacuate the lines and then add the R134a or they have the R134a that supposedly absorbs water that you use in a new or empty system. In the case of it being empty then yes an AC specialist may be a good idea. They can sniff out your leak with a halogen sniffer.
 
they can also add dye and use a UV light to find the leak. if they open up the system its usually recommended to replace the dryer and all the o-rings. some people also replace the schrader valves.
 
Originally Posted By: mechtech2
Ford testing shows an average of 7 ounces a year loss of refrigerant. Seems high to me, but it shows loss is normal.
Leaks at junctions,the compressor seal, and even right through the rubber lines accounts for this.
So after 9 years, you are long overdue for a shot of fresh refrigerant.


7oz/year? When was this testing done....1970? No modern A/C system (by modern I'll say since the switchover to R134a back in the mid-90's) will lose anything close to that amount unless there is a leak.
 
I'll bet somebody misinterpreted original data. Ford probably specified 7 oz. loss per year as the acceptable maximum before repair is needed. I'm sure we've all played "telephone" when we were kids. I really doubt Ford vehicles - or any vehicle - would average a loss of 7 oz. per year.
 
I havent had time yet to have my mechanic take a look but something Wierd is going on!!! The ac startded wroking again but now there are two noises. I turned the ac on and it blew cold air fine but there was a knocking sounds tock tock in like a one second ryhtm!! When I drove I couldnt here the knocking probably because of engine noise?? I stopped at a light and there was no knocking noise but a could seconds after I drove of there was a howling nose like the sound a jet engine makes coming from the ac!!! I turned the ac of and the noise stopped immedeatly. while standing i turned on the ac and there was no noise but once I took off the howling noise started agian!! What could it be??? I really don't have time until some time next week to have it checked.
 
I have the same problem you do. After a 500 mile drive with the AC on it won't even hold freon anymore. I put it in and it's leaked out the next day, or so it seems. The compressor doesn't run anymore at all.
 
I recall reading something about Fords losing refigerant, I thought it was 4 oz/year. Most of the older cars leak over time, some don't. I found GM to have the best AC of the domestic cars. Fords leaked from 0 rings. Mine holds a charge for about 5 years. I still have about 25 LB of R-12, so I don't have to do any conversions.
 
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