Hola. I need to replace the a/c compressor (as clutch dnw- has power) and the guy at auto parts store says I also need to replace the expansion valve (for $35.00). I don't believe there are any leaks in the system as even with the clutch not working, the system does not blow hot.

Wondering if the existing expansion valve is ok, or if I need to replace.

Thanks for the replies in advance!

If it was OK, leave it alone. If you are opening the system, consider replacing all the TXV "O" rings.

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'83 300D, 126K miles.

thanks

If the compressor clutch is inop, the a/c system blows the same temp whether the refrigerant level is full or empty.

Did your parts store advisor recommend replacing the receiver/drier?

They did not specify that anything else "had to" be replaced to meet the compressor warranty, but were the ones that suggested doing the expansion valve. Honestly, i don't know that they know very much about this car. When I asked how many cans of 134a I needed, they said their book did not go back that far. (Would like 5-6 cans be more than adequate? I can return what is unused).

Also the shop that is going to do the work did say that according to their book, the accumulator is a 17 hour job :-\ and we agreed to leave that alone.

Thanks.

accumulator in a MB W123? 17 hours?....

it uses a liquid line drier and is only held on by two flare nuts and a clip.

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2012 BMW X5 (Beef + Granite suspension model)

1995 E300D - The original humming machine (consumed by Flood 2017)
2000 E320 - The evolution (consumed by flood 2017)

Maybe his book doesn't go back that far either :-{ LOL

So accumulator and drier are same thing? Is there anyway to tell if i need to replace it? Thank you.

You didn't list your location, but as long as you're starting from scratch, I would stay with R12, and I mean R12, not any of the "designer" replacements. It will cool better on hot, humid days, conserves engine power, and is easier on the compressor than 134. It is still readily available on ebay.

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'83 300D, 126K miles.

I agree that R12 is better, but it's already been converted to 134a. I'm in MO btw- gets pretty darn hot here too, but not like FL where i came from . Appreciated.

Is the problem the clutch, or has the compressor itself failed. If the problem is the clutch, replace only the clutch. If that is not possible and an entire compressor is being replaced, but the old one did not internally fail, the flushing and expansion valve replacement will be unnecessary.

Since you don't post your location, what kind of climate are you in? This would be the ideal time to reverse convert and put back the refrigerant that belongs in there.

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2001 SLK 320 six speed manual
2014 Porsche Cayenne six speed manual

Annoy a Liberal, Read the Constitution

I'm in southwest MO and unfortunately, subject to the limitations of the local auto parts and service shops. I am a DIY-fer, especially on this car- but don't really have all of the tools to do everything, and limited knowledge of a/c parts.

I believe for sure it is the clutch, as I have confirmed that it is getting voltage all the way up to the clutch. It was my understanding that the clutches are specific to the compressor (i.e. not universal). I did have the compressor/clutch replaced about 7 yrs ago but not sure of the mfr. I don't mind replacing the comp/clutch together as both reman and new have 2-yr warr.

Excuse my apparent ignorance, but there I believe the drier is located in the RF fender area...(round device w/sight glass?) if so, looks like pretty easy for repair guy to R&R and probably worth replacing @$65.00...? Thanks.

Contrary to what the auto parts person told you, I'd highly recommend replacing that receiver/dryer -- the silica inside those things wicks the water out of the air, and they saturate pretty quickly. And water is like the *very* last thing you want in the system.

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Java Developer/Linux SysAdmin

Current:
*1984 300D ~200K,1989 MR2 250K, 2012 Ford Fusion 4.5K (fiance's car to replace the uber-unsafe cavalier)
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Past: 1998 Chevy Cavalier ,2005 Saab 9-3 2.0T, 1996 Mazda Protege, 1974 Porsche 914 2.0, 1997 Land Rover Discovery 4.0L/5Speed, 1995 Jeep Wrangler

First you need to make SURE what the problem is. It sounds as if the case might be that you only have a bad or misadjusted clutch. Try jumping 12V directly to the clutch and see if it engages. If it is not engaging, do some research and check the air gap. If the air gap is not excessive and the clutch still does not engage, replace only the clutch.

If you can get by with adjusting or replacing the clutch, you will be saving yourself a HUGE amount of work, due to all the disassembling for flushing, replacing, and evacuation that accompanies compressor replacement.

Assuming that the clutch engages with the 12V jump AND the Climate Control Unit (CCU) is giving the proper signal, then you might have a bad compressor. If it IS the compressor itself to a point where it must be replaced and it failed internally, all line connections will have to be broken and the lines thoroughly flushed of debris. The expansion valve needs to be replaced, but if you can see it well enough to know that it is properly flushed, you can leave it be, with the understanding that it will compromise the new compressor warranty.

In the case of a catastrophic compressor failure, you should indeed replace the r/d and it is in the passenger side front of the engine compartment. Do not install the new r/d until EVERYTHING ELSE is complete and reassembled. Be ready with the vacuum pump and install the r/d and immediately began evacuation. The reason for this is that the dessicate in the r/d begins absorbing moisture as soon as it is open, so you want to begin evacuation so that it does not saturate before it has a chance to dry the system.

Also, any time you are working on the a/c system of one of these cars, remove the glove box and ensure that the soft line going across to the center vent in the dash is intact. It originally was a foam hose that deteirorated and disappeared in a few years time. Foam pipe insulation from Home Depot makes a good substitute because it does not conduct heat very well at all and there is no significant pressure to be dealt with.

Hope this helps.

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2001 SLK 320 six speed manual
2014 Porsche Cayenne six speed manual

Annoy a Liberal, Read the Constitution

Thanks for the thorough reply. I am getting power at the clutch terminals but obviously no engagement of clutch. Is it correct in what I was told that clutches are specific to the brand of compressor? Thanks.

Thanks. I am going to do so.