Planning Air Conditioner Repair
 

1992 190E 2.6
Zero Air Conditioning
Seems there is no freon

Please comment how I should Address the issue ...

How do I know when the compressor is bad - when there is no Freon in the system?

We tried recharging the freon last year - but leaked out quickly. We were just trying the - it took years to leak, maybe it will last years. It did not.

As thei has the "Old" freon, should the old be fixed?

Should I consider replacing stuff and just convert the system to the 134 freon?

In general, the car is running well - so I'm of the mind set to keep it. Other required work includes speaker repair and timing change replacement.

Zero rust, and no oil leaks.

Thanks for the comments and suggestions. ;)

If nothing else I'd convert it long enough to locate the leak, add BG "fridgiquiet" with dye. Once you nail the leak, decision time. R134 works OK but not great in the older 124 and 201 cars. The 201 never had 134 so there are limited options to enhance performance. About the only thing you can do is install a 134 expansion valve and set the fans for "always on" low speed. Make sure your fan clutch is good and tight and run the latest version of the compressor that will fit on the car, I know there are a few different clutch pulley sizes as well that will turn the compressor faster for better cooling performance with 134. (I just did a replacement on a 89 201 car, the replacement was 1/2 shorter than the orignial, cooled much better and the pressures were better)


Joe

Is the Compressor the same fo rthe old and the new freon?
 

Some of the components between the old and the new (r134) freon share parts.

Is teh compressor one of them - or is it commonly replaced -

Please identify the parts that are replaced in a conversion.

many thnaks

Assuming the system is healthy (any worn or damaged parts replaced), conversion involves the following steps:

- Flush all old lubricant from the components (except dryer, expansion valve, and compressor) using mineral spirits, followed by laquer thinner or brake cleaner.

- Replace joint seals with ones that are compatible with r134.

- Drain and flush lubricant from compressor. This is accomplished by hand cranking new lubricant through the compressor on a bench.

- Add specified amount of r134 compatible lubricant.

- Replace dryer.

- Button system back up. Pull vacuum.

- Charge system with r134. Should take about 80% of specified r12 charge. Though I have manifold gauges, after a conversion I like to charge to acceptable vent temperatures. That is, charge until vent temperatures don't drop anymore.

If you search through old posts, you'll learn many of the finer point of a/c repair. It's not difficult with the right tools. For your job you'll have to find a source of shop air for flushing and a vacuum pump. Without these tools, you're really doing a half-baked job and wasting your time.

Ain't there any laws stateside that prevent you from knowingly releasing freon into the atmosphere?

Sounds to me as though you need to refer this to a specialist - largely because you do not have a clue what you are doing.:rolleyes:

Yes, we have laws against knowingly venting r12 into the atmosphere. But if the freon has already escaped, no laws are broken.

HFC-134 refrigerant is widely available over the counter at just about any auto supply house, except in Wisconsin. This has to do with safety, since a lot of shadetree novices hook the bottle to the wrong (high pressure) side, which can have disasterous consequenses.

Sorry Kestas my response wasn't aimed at you

Didn't think it was.

Perhaps we should back up and advise Bill that he first needs to find if there is a charge in the system. This can be done with a/c manifold gauges to measure the static charge. Something like 70 psi should indicate a full charge. If there is no charge, the source of leaking should be found.

Bill, post back with the results if you decide to tackle it yourself. There's a whole lot of "ifs" when diagnosing the system.

No Freon left - ....
 

I didn't press the mechanic for the specifics, but he said the Freon is gone.

From the sounds of Kestas replies - I’m assuming I can purchase a new compressor, that may have been designed for R12, and use it with R134.

What brought this Air Conditioning question to light, while it is 10 degrees Fahrenheit - the pulley on the compressor is starting to lock, in addition to the Freon being gone.

Please confirm - if I purchase a Nippon compressor from Fastlane - it will work with R134, even if it was originally designed 12 years ago, before R134 was available.
Unfortunately the mechanic may not permit me to bring the parts in - I am not doing air conditioner work - don’t have those tools.

I’m considering if I should keep the car. I want to be USA legal, and I don’t want the R12 leaking. But if the air conditioner will not work, perhaps I should offer the car to a teenager.

Many Thanks for your suggestions

If the compressor pulley is starting to lock, you may only need to replace the pulley - a lot cheaper than replacing the entire compressor. You still have to find the leak though. If the leak is at the compressor, such as a shaft seal, then yes, a complete rebuilt compressor and pulley is in order.

I'm pretty sure a/c compressors are compatible with both r12 and r134. Check first with the supplier to be absolutely sure.

I can understand why a mechanic wouldn't want a customer-supplied a/c compressor. He needs to guarantee his work. Plus he may have a relationship with his supplier. Shoud the a/c compressor crap out, it would be a lot more difficult (involved) to replace than say an alternator.

Sadly, your plight is rather typical of people who own older cars. Usually, when the owner sees the cost of repairing a/c on an older car, they opt to replace the car, even though it's otherwise running fine and serves the driver well. Cold a/c is important to a lot of drivers. This is also one of the more financially rewarding repairs a DIYer can do.

Perhaps you should contract and pay your mechanic to first do a diagnosis. He can find the leak and figure what needs to be replaced. If the machanic who charged the system with freon last time had any foresight, there's a good chance he probably put dye in the system. Only then can you make an informed decision.

Thanks
 

Thanks for the suggestions.

My questions have been answered.

I will post the findings of the mechanic.

Ah - the Air Pump
 

Well - I was wrong yet again -
The air compressor was not broken - the air pump.

The air conditioner issues will be put off for another day.

Oh - Happy days
 

The air pump seized, not the compressor.

The mechanic inspected things and the freon leak is at a joint near the evaporator.

We will change to R134 and fix leaks in several months.

Thanks for the help.:)