How to tell if your AC compressor is bad?
 

I've got a mechanic telling me my AC compresser and evaperator/dryer are bad and need to be replaced. I bought the car off Ebay and the AC worked for about 300 miles.
I've purchased a 'parts car' of the same year and modle and I was going to take the compressor and dryer off of it. The engine on the parts car doesn't run and when it did, the former owner said he wasn't getting any cold air off of it. So, without knowing how to tell if the AC compressor is working, I don't know if it's worth the time and effort to take the part off the 'parts car' other than hoping it works and saving about $400 in AC parts.
(It's about another $300 to $400 for labor and freon.)

What flavor of car are your writing about?

A compressor can still operate even with leaking seals. Make the mechanic tell you what is wrong. It is standard practice to replace the dryer along with the compressor. In a perfect world, the dryer should be replaced any time the A/C system is opened.

Do not use a used dryer. They are usually $50 or less. Cheap insurance. A plugged dryer will cause the system to not function, or worse.

HeyTX76513,

I'm working on a 1985 300SD Turbo Diesel.
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not a foolproof test but....
 

put your hands on the compressor and turn the metal center part, usually with three angle parts forming a triangle.
if it is free, at least you know the compressor is not siezed up.
John

PM me your email address and I will send you the 21 page pdf document to test every component on your 85SD ACC. Don't get overwhelmed with the amount of information, but it's a good idea to become familiar with the beast. ACC can be a real bummer as you probably have read many threads on the subject. With that said, once you get the idea of how everything works there not that bad. There are plenty of pictures to help you identify components

I'll drop ya a PM too, my '85s will be gettin' fixed this weekend hopefully.

Given the cost of labor and freon, it just isn't worth it to fool around with salvage parts. The drier is not reuseable, anyway. You can buy a new compressor for around $200.

Saving money on A/C repairs usually turns out to be an expensive proposition.

Napa Auto has the R4 version which I think is whats on that car for 130 bucks. Its a reman but for the price you get a warranty. A cheap option but way better than junk yard ac parts.

Do you know the p/n and would that fit my 75 240D?

I dont have a clue whats on the 1975 but Its prolly the older Sanden one. That one looks like a bilge pump sitting on the pass ide of the engine. The R4 look slike a doughnut.

not that mine works (spins freely, but i think it doesnt work) my 76 300d has a york compressor

Unless it's been retrofitted, a '75 240D will be equipped with a York recriprocating compressor. A retrofitted car would have a rotary Sanden.

TX, can I get in on that offer also? It will be appreciated.

Thanks,

Padraig

Sent:)