Air Conditioner freon leak

volvo_user · Post by **volvo_user** » 25 Jul 2004, 17:24

The air conditioner of my 88 740T stopped working last year. I took it to the mechanic who said that he has put in a conversion kid and fill up with the new type of freon ($200 job). It worked for a week and it stopped working again. The mechanic claimed that the freon has leaked out because there is a leak somewhere. He told me that if the leak is the hose, it'll cost me $600 to replace. I did not do it last year because Summer was almost over. I need some advice from other users if my mechanic is honest. Is it $600 to replace the hose ? Is there anything that I can do to find the leak and just do what is needed to fix it ?

potroast · Post by **potroast** » 25 Jul 2004, 17:57

doubt it's $600 for a hose... What is the cost of the part and what labor is he charging (and ask him how long). Also, ask for the name of the part.

I don't think you mean freon, I think you mean hfc-134a, which replaced r12 for environmental reasons.

petershen1984 · Post by **petershen1984** » 25 Jul 2004, 20:03

argh, I feel your pain buddy... blame the car for its old age, but ever since I performed the retrofit just for replacing a faulty radiator, I've had the hfc-r134a leak out through the high pressure and low pressure hoses (they lead to and from the dryer and the compressor) on three distinct occasions. if I have another refrigerant leak I'm gonna go insane!!

A.Baker · Post by **A.Baker** » 27 Jul 2004, 09:36

There is a lot you can do. First dump the mechanic. the reason you an the freon and (hfc134a) is that the old hoses for r12 were not barier prof. The molacule for 134a is way smaller then r12 so the old hoses tend to leak. So make sure ther berier prof hoses. volvo will tell you that. If you are half way good w/a wrench replac the hoses your self.REMBER. Two things. Replace the o-rings @ both ends of the hoses(oil soak them first. The oil will come in the retro kit) next w/a/c work cleanlyness is next to godlyness. Replace the compressor oil and take it to a good a/c shop to have it recharged.Follow the retro kit instructions. DO NOT put freon it the system w/out a complete vacum. NO the a/c compressor will not pull the vacum for refill.
hope this helped
A.Baker

petershen1984 · Post by **petershen1984** » 11 Sep 2004, 08:26

I don't work on my car myself, but I still enjoy, through participating in this forum and doing online research (for leisure) to learn more about my car.

I still remember that my first R134a leak occured two days after the retrofitting and 15-minute vacuum and refill. The "Volvo Cars Taiwan" (established after the acquision of Volvo by Ford) mechanics blamed the leak on a coincidental failure/fatique of these old pipes (the high and low pressure pipes from compressor to dryer), but I had every reason to believe that my R12 wouldn't have leaked on that same day if left undisturbed. Then I did a reading a few months later and learned that the initial leak could be attributed to the residual old mineral oil lube in the pipes being mixed with R134a and Ester oil.

Afterwards, within sixth months I've had the freon completely leaked out through High Pressure pipe twice, and my current mechanic, a father-son Volvo shop, blamed Volvo Cars for a shoddy worksmanship (lack of experience with older Volvos, and something about how the pipes were mounted made them suspectible to damage from engine vibration). Although both times, the service was performed under warranty (which is bound to expire in November), I found it frustrating to one day start the car and have no air-conditioning, with no computer notifications or any early detectable signs of failure. (other than HOT AIR)

Eventually, after the LOW pressire line had failed (asking for more dough), I dumped Volvo Cars after they quoted a price beyond warranty repair (they offered to recharge my freon for free), and had the pipes replaced at this father-son Volvo shop. They use the same authentic parts at a bargain price, charge less for labor, and they have the capability to work with modern Volvos because they have the PC Interface Software for reading the communications ports.

I feel sorry for my dad because it's costing him so much to let his son drive this car (but I'm convinced its less than buying a new Toyota for now).

Volvord · Post by **Volvord** » 11 Sep 2004, 11:09

A couple of quick comments. First A. Baker is right on with his assessment of the R134a. The smaller molecular structure of the product makes it a real challenge to create a completely leakproof system. It takes the mechanic some time and attention to detail to ensure their work is done correctly.

The R12 and R134a products are not compatable, also air and moisture and disaster with and A/C system. When retrofitting it is very important to completly flush any residual oil and R12 from the system, replace any questionable hoses, replace the reciever dryer, flush the system with a nitrogen purge, add the correct amount of R134a compatable oil, fully evacuate the system with a vacuum pump and then fill with the correct amount of R134a refrigerant. Finally the system must be very carefully tested for leaks.

This process takes time and a competent mechanic who takes pride in their work.

petershen1984 · Post by **petershen1984** » 12 Sep 2004, 00:43

I'm not even sure if they even did the Nitrogen Flush..

I'm putting my money down on they didn't.

Davedaknight · Post by **Davedaknight** » 29 Oct 2004, 16:26

It's a conversion okay- emphasis on the CON. My '90 740 went out in 1996, I took it to a specialty airconditioning shop, and for $60.00US in parts and $75 in Freon, I was back on the road. Unfortunately, that shop is closed. My airconditioning went out in '02 and I took it to the dealer after all the other shops in my area refused to work on Volvos. The dealer quoted me $1400.

to convert to R134a- with a 90 day guarantee. The secondary shop that does Volvo work in our area quoted me half that -$700- but told me from the get-go that it would never be even as close to cool as the original because the system simply doesn't work as well with "tree-hugger Freon." He also said I'd probably be getting a flush and recharge every year after CON-version.

Volvord · Post by **Volvord** » 29 Oct 2004, 19:36

Your right that prices vary greatly from shop to shop, but there is a high cost to providing AC services with the equipment and "environmental" fees. Your point is well taken, shop around.

R134a does have a lower btu equivelancy and will not be as cool as R12, but most vehicle AC systems are designed to be larger than required so R134a usually does a good job of cooling. The more frequent recharge is because the newer R134a is a much smaller molecule than R12, it is small enough that it actually migrates (leaks) right through the rubber hoses. There is nothing that can really be done about this problem.