Compressor failed spectacularly
 

Had the compressor filled at or slightly below operating pressure, about 85 degree ambient. Was looking for leaks in the cabin with the engine idling and the AC on, had only ran for a couple of minutes. Without warning the system discharged rapidly. I shut the car off and ran while it cleared out. The r4 compressor split open where the rear piece met the body. It actually forced the main O ring out between the case seam. I am going to have to replace my parallel flow condenser that has about 1 hr of operating time on it probably, will be returning the compressor, and upgrading to a sanden kit with 100% new lines for the entire system, and replacing the (possibly leaking, not sure) evaporator.

At a cost of around $2k when all is said and done...

Will post pictures of the failed compressor when I pull it out.

It the shaft still turns and no rattling sounds, the compressor hardware is probably fine. If true, I doubt it sent anything into your condenser. Sounds like one of the circumferential O-rings just extruded. Big suspicion is that the rebuilder's used the wrong size. As I recall, the R4's outer steel shell just slides over the aluminum guts, and the only thing securing it is some bent tabs. If it slides too far either way, an O-ring can blow out.

For $2K, you must have had shops involved. I put a Sanden on my 1985, w/ new hoses, and probably spent $300 total ($200 Rollguy's bracket, $50 new compressor, barrier hose from ebay). I kept the R4 on my 1984 and probably spent $50 on new hose, oil, and refrigerant.

I guess I could save a ton on hoses by making them myself and buying/reselling a crimper. Or I may send all of mine out to be rebuilt (30-50$ each roughly to be rebuilt)
New condenser kit was on the pricey side at ~300 including brackets and hoses for it.
Compressor with brackets and new high side hoses I was considering is 600$. How did you get a sanden for 50$?
New evaporator is about 250
Considering an oversized aux fan for 150$. Or i can invest time in sourcing and rebuilding a w126 fan and making it work.
Might need another condenser. Will depend what the failure mode was on the compressor.
Hoping to return the failed r4 and get my money back, depends on if i can find the receipt and/or if the parts place will help me out. I am a regular there so pretty hopeful they will help.
Ugh. 4 or 5 driers now, one was ruined trying to remove a sensor plug that was painted in. One replaced with the drier last year, one after rebuilding the system and finding it was clogged, one more when I upgraded the condenser, and now one more thanks to having to reopen the system now that my compressor com-ploded.
And some oul, r134a, and having the system evacuated.

If I EVER touch ac again after this, I will be replacing everything upfront that MIGHT be bad.

Yes, the R4's case just slips over the body. If there's no metal filings in the system your condenser is fine.

-J

What kind of compressor was it, new or rebuilt? Where did you find an evaporator for $200? They are nla from MB. Here's a NOS genuine unit starting bid $750 Mercedes A C Evaporator W123 OEM NIB 000 830 46 58 | eBay

Brand new compressor.
Klima Design Works | W123 Evaporator

Sorry for your troubles... Question, did you install this bolt supporting the high pressure line?

http://www.peachparts.com/shopforum/...23-brazing.jpg

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Yep, I installed that bolt.

What were the hi/ low pressures on the manifold gauges when it blew? I recall you said the last can of R134 was leaking. Was it possible air got in due to the leak? Did you purge the yellow hose between cans?

Do you have the HF manifold gauge set? I have found that you need to use pliers to snug the fittings a bit more than just finger tight otherwise they could loosen up on you if you move the gauge set around. Did you pressure test the gauge set (easy to do with a tub of water) before use to insure it does not leak?

The quick couplers have o-rings in them. They must be well seated and not chewed up.

Does it look like this?
http://www.peachparts.com/shopforum/...1&d=1469454737

ROLLGUY's thread of his start to explore the use of a Sanden compressor.
http://www.peachparts.com/shopforum/diesel-discussion/369674-i-should-have-known-better-than-try-bring-gm-r4-compressor-back-life.html

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Just read the linked thread's first post. He said: "with the exception of a bad Klima relay, so the compressor was hot-wired". Don't know how the compressor was hot wired, but if it was hotwired to be always on, that may have been cause of the compressor blowing up.

Did purge the yellow line. Possibly it leaked, but I cant imagine much if any air got in while it was pressurized. Really dont know the manifold readings on the day it failed. The previous day it was charged to correct pressure for thr ambient, but on the day it failed I had just started the car about a minutr earlier and was still in thr cabin. I had run it about an hour the day before but was not getting very cold air (55 to 60 or so). I did wrench tighten the manifold set, and ran the sniffer around it, but I didnt think to run it under water. We never actually got the full 80% capacity recommended for 134a into it.

It looks exactly like that DelveryValve. Except I had recently flushed the system and added the proper amount of oil per the FSM. Also mine had oil that blew out with it.

I may take it to an indy to fill this time, so they can go by weight off of a large bottle not a can.

My Klima relay is unmodified. The compressor does cycle properly. It also had a new pressure switch. I did jump the aux fan temp switch to make it run always on while I was testing, and I had a ~18" industrial type fan blowing at the condenser.

New evaporator may be out of stock. I just ordered the compressor kit, an upgraded fan, and a set of crimpers for full size hoses. The person who was advising me said that the liquid line to the TXV needs to be reduced hose, and since that die costs about as much as it would to have the hose rebuilt, I'm just going to ship them the hose to rebuild for me - but I'll be replacing all of the suction side hoses, and between my PF condenser kit and the Sanden kit all of the high side hoses will be new. Also have all the ferrules and new ends for the hoses, except the custom bits for the suction lines that I'll have to re-use as they are not available. Will be getting some full sized #12 hose shortly as well.
The guy I was talking to advised me to take the evaporator in to a radiator shop to leak test, in case they are not able to source me a new one. If it is leaking, they said a shop might be able to repair it for me. I know it's a ton of work to pull it, but I was also pretty underwhelmed by the air speeds I was getting out of the vents, so even though I cleaned the coil with foaming cleaner, I might as well pull it to clean at the very least.

More importantly, did you install a hose that uses that bracket? This bracket keeps the compressor can from sliding off. If the can did slide off, I would not call that a compressor failure, more of an install issue.

If the body o ring was too small, it would have leaked from the start, if too large the can would not slide on or o ring get cut during install at the factory and leaked from the start.

What were your low and high side pressures?

The bracket, hose, etc were all correct
As i said earlier, we charged it the previous day, but the day it failed i had just started the car and hadnt gotten out to check manifold pressures, so I dont know the pressure, except that is now at 1atm absolute pressure due to having an O ring halfway out of the system.

Your post 12 says the can looks like the one in post 10. ( slid forward ) For the can to slide a washer or bracket had to be missing or improperly placed on the side it slid towards.

^^ yes another question, was the washer on that nut for the high pressure hose support bolt?

The liquid line is still available new from the dealer. If it is more than $100 to rebuild that hose, you might be able to find it cheaper. Part number 1238301015. Fwiw, I paid $54 for a new Behr hose in 2013.

Oh wow, I hadn't looked at the other picture well enough, I saw the O-ring pushed out but not the huge gap in the can - no, the can didn't slide forward, or if it did, not very much - it just forced the O-Ring out.

I would bet your compressor did not blow up internally, so your condenser should be fine.

If that look at the pic, the o-ring sits in a pretty deep groove. For that o-ring to blow out, I'd say the casing has to slide back a little, or the casing deformed somehow.

Well, looks like this was my fault after all. Apparently I forgot to do a final torque on at least two the compressor bracket bolts, or they loosened on their own. Most likely I forgot to torque them. I am not going to return the compressor now since this was clearly my fault.

And this is why I used touch up paint to mark suspension bolts after torqueing them. Plus it easily indicates if they have backed out for later inspections.

Once the evaporator is out, pressurize it with compressed air, place condenser under water to test for leaks. I'd bet that's what the radiator shop would do.

Just pulled one of the liquid hose ends in order to have it rebuilt. Even after flushing it i found quite a bit of gunk inside. Guessing this was the black death. Probably from the original compressor. Would this have contributed to my mediocre cooling?

You don't like to use pics to show what it looks like do you? Didn't you have other hoses off before when you replaced the TXV and dryer? What did those parts look like as far as signs of black death?

I didnt grab pics, and havent figured out a way of scaling them on my phone to upload under the file size limit, so it takes a bit to post them

I didnt stick q tips in the hoses while i was rebuilding it previously, didnt want to risk getting lint in there. I flushed the original system with four large cans of flush split between every hose until it came out clear. Will check other connections tonight and upload pictures.

Upload pics to hosting sites such as Photobucket (what I use), Imageshack etc and post the links. Much easier. All can be done from your phone.

I get the feeling that replacement evaporators are difficult to come by. I'd be super careful with the one you have. Rig up a pressure test setup like mine and test it in situ to make sure it is indeed leaking before pulling it to repair it.

I prefer to upload pictures here, that way five years from now they wont have been purged from the sharing site, and they might be of use to someone. It's super annoying to find a thread on a forum which might be useful, only to find a bunch of broken images because they were purged due to an inactive account or expiration date.

Fyi: I know starting in the 1983 model year, there are two original manufacturers of the evaporator box . Siemens and Behr. The evaporator itself do not interchange between the two brands.
Before you order an evaporator, make sure you check to see which manufacturer you have. I made that mistake, ordered a brand new evaporator for a Behr box and it didn't fit my Siemens box. I ended up getting a whole box out of the wrecking yard and another evap from a forum member. I used wrecking yard one and kept the forum member one as a spare.
Btw- the Siemens evaporator core is about a 1/2 to 1 inch wider that the Behr core.

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I totally agree with that super annoying piece. I am always like Ugh! I wish pictures are here in this great thread!

Great information! Do you know where to look for a brand marking on the evaporator box by chance?

You may want to figure it out quickly. Pics are worth a thousand words and help you communicate. Pics may possibly have saved you from some of the mishaps.

Here's the liquid line before I mail it out to be rebuild. I already got most of the gunk out of it last night, but was still able to get a bit more out today. There's a bit of corrosion inside the hose, as well as where the O ring sits. Edit: a bit on where the hose o ring seats as well.
I'm pretty much going to have to re-use this as well as the other metal pieces, such as the metal parts of both suction lines. I wonder if it's worth soaking them in a rust converter then flushing them really well after I cut the rubber hoses off of them?

If you pull it the whole HVAC apart, you'll see a large Siemens casted on the top of the evaporator case.

If you are not pulling it apart, it is harder for the untrained eye by looking at the shape of the box. But you can also tell by pulling and checking the blower, if it's original to the car. The Behr blower will have a caged center on the fan. The Siemens blower fan is solid in the middle.

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Agree totally.... that is happening all over the internet on all sorts of forums on different subjects...

What kind of flush agent did you use and how did you insure none was left in the system? I have heard some flush agents can cause problems if even a little was left in the system. Not saying that is what happened to you. Just like to know the cause of the R4's demise. How far back did the casing slide back? Do you have a better pic than the one you posted that would show it?

From someone who has never posted a pic as far as I know.

Remember, I have no apps on my smart phone.

Edit... I am sure I posted pics of my homemade / bent ' bent wrenches' for valve adjusting..

So you can't tell unless the blower is the original to the box? If I post a pic of the underside of the box that's in the car, can you tell which box I have?

Go ahead and post a pic, I'll see if I can identify it.

Here are 2 shots with camera zoomed out all the way, hard to get a wider angle due to space limitation. Let me know if you need other views/ angles.

http://i31.photobucket.com/albums/c3...726_113109.jpg

http://i31.photobucket.com/albums/c3...726_113151.jpg

If you can take a long shot picture of the expansion valve area, that may help more. But looking at current pictures, I would guess to say you have a Behr evaporator.

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Is this one better?
http://i31.photobucket.com/albums/c3...726_143916.jpg

I think it's a Behr. One more picture of expansion valve facing the side of the box please.

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I am 99% sure it's a Behr. Btw-you couldn't see your picture without logging on. I bet you uploaded your pic in your user photo album instead in the thread itself.

Thanks! Yes, my pics has always been uploaded to Photobucket. Never tried uploading to the thread itself.

You wrote: "starting in the 1983 model year, there are two types of evaporator box original manufacturers. Siemens and Behr. The evaporator itself do not interchange between the two brands. "

Does the Behr evaporator have a different p/n than the Siemens?
Which evap box is currently installed in yours?

Funola, So you do not agree with Demothen's view on this subject... ?
Did you understand the concept ?

Where did I say I do not agree? :confused: What makes you think I do not understand the concept? If an intelligent guy like Demothen cannot figure out how to post photos within a thread to Peachparts, maybe it is not very user friendly? All my photos on Photobucket are still there. I can see that they can all disappear if I decide to delete them from Photobucket, which I have no plan on doing.