my Air Conditioner is upside down - PeachParts Mercedes-Benz Forum

thayer · #1 07-08-2010, 11:53 AM

Here is some information I found while researching the r4 compressor and it's uses on both GM and Mercedes. I found this fascinating.

Re: [MBZ] AC Compressor woes...

Royce Engler
Sun, 11 Feb 2007 21:54:49 +0000

Thanks, Marshall...that's the post I was looking for. I'll show it to myindy and file it in a safe place.Best Regards,RoyceRoyce Engler1985 300TD Turbo 290K-----Original Message-----From: Marshall Booth [EMAIL PROTECTED]Sent: Sunday, February 11, 2007 2:42 PMTo: [EMAIL PROTECTED]; Mercedes Discussion ListSubject: Re: [MBZ] AC Compressor woes...Royce Engler wrote:> Gents,>> I seem to recall a discussion at one time about AC compressors on 123's> being mounted "upside down"...and if not mounted right side up, failingdue> to improper oil distribution in the compressor... Anybody remember orknow> the answer?>> My compressor has once again seized up, and last time I was under there, I> thought I noticed that it seemed like it was upside down from what I> remembered. My indy does all my a/c work, and this will be under> warranty...just had him completely overhaul the a/c system a couple of> months ago, but I'd like to solve the compressor seizeup problem once and> for all. I've probably gone through 4 or 5 compressors in the past 2 or 3> years. After replacing the mono valve and resoldering the ACC board, Iwas> getting real used to the climate control working correctly. ;-(>> Royce Engler> 1985 300TD Turbo 290KThe sure fire solution is to buy the compressor from a parts supplierthat will sell you a compressor that is configured to work on a Mercedes- and if it fails, will provide you with a replacement and the cost ofthe labor!As to the X or lack thereof:> "A word of advice on buying a replacement compressor:> Any one you get that does NOT come from Mercedes will have the frontbearing> cover installed UPSIDE DOWN. Look at the cover on the front behind the> clutch. It will have 4 bolts. Between 2 of the bolts will be an embossedX.> This is the position of the oil hole to lube the front bearing. The R4> compressor was originally designed for GM cars with the compressor mounted> on top of the engine. The X and the inlet/outlet port is UP. Mercedes used> the compressor but rotated it 180 degrees and mounted it under the engine.> This put the ports DOWN. Then they rotated the front cover so the X is UP.> Oil does NOT flow uphill. If you use an aftermarket compressor with the X> down, you will starve the front bearing of oil. It may last a week, amonth,> 6 months.... depends on the quality of the bearing they put in. "I have received feedback on that information confirming that it isbasically correct. That DOES NOT Mean that if you mount an R-4 upsidedown, it will fail prematurely - only that it is much more likely tofail prematurely if you mount it upside down.I have had many people dispute this and tell me that, "I mounted mycompressor without an X on it and it's still working 10-15 years later.No argument, but there really is a reason why Mercedes marked theircompressors and most of the guys I've spoken with that do this for aliving (and don't want comebacks) insure that they use compressorsconfigured to work on a Mercedes.Marshall--Marshall Booth Ph.D.Ass't Prof. (ret.)Univ of Pittsburgh School of Medicine[EMAIL PROTECTED]

4thesporty · #2 07-08-2010, 12:07 PM

This is good info from a very respected source.

As you and I seem to be on the same road to functioning CC in our cars it is very important.

I have gathered everything I need for my A/C except for the compressor as I have also been doing some research on brands. Thank you for posting.

85chedeng300D · #3 07-08-2010, 02:42 PM

Quote:

Originally Posted by thayer

Here is some information I found while researching the r4 compressor and it's uses on both GM and Mercedes. I found this fascinating.

Re: [MBZ] AC Compressor woes...

Royce Engler
Sun, 11 Feb 2007 21:54:49 +0000

Thanks, Marshall...that's the post I was looking for. I'll show it to myindy and file it in a safe place.Best Regards,RoyceRoyce Engler1985 300TD Turbo 290K-----Original Message-----From: Marshall Booth [EMAIL PROTECTED]Sent: Sunday, February 11, 2007 2:42 PMTo: [EMAIL PROTECTED]; Mercedes Discussion ListSubject: Re: [MBZ] AC Compressor woes...Royce Engler wrote:> Gents,>> I seem to recall a discussion at one time about AC compressors on 123's> being mounted "upside down"...and if not mounted right side up, failingdue> to improper oil distribution in the compressor... Anybody remember orknow> the answer?>> My compressor has once again seized up, and last time I was under there, I> thought I noticed that it seemed like it was upside down from what I> remembered. My indy does all my a/c work, and this will be under> warranty...just had him completely overhaul the a/c system a couple of> months ago, but I'd like to solve the compressor seizeup problem once and> for all. I've probably gone through 4 or 5 compressors in the past 2 or 3> years. After replacing the mono valve and resoldering the ACC board, Iwas> getting real used to the climate control working correctly. ;-(>> Royce Engler> 1985 300TD Turbo 290KThe sure fire solution is to buy the compressor from a parts supplierthat will sell you a compressor that is configured to work on a Mercedes- and if it fails, will provide you with a replacement and the cost ofthe labor!As to the X or lack thereof:> "A word of advice on buying a replacement compressor:> Any one you get that does NOT come from Mercedes will have the frontbearing> cover installed UPSIDE DOWN. Look at the cover on the front behind the> clutch. It will have 4 bolts. Between 2 of the bolts will be an embossedX.> This is the position of the oil hole to lube the front bearing. The R4> compressor was originally designed for GM cars with the compressor mounted> on top of the engine. The X and the inlet/outlet port is UP. Mercedes used> the compressor but rotated it 180 degrees and mounted it under the engine.> This put the ports DOWN. Then they rotated the front cover so the X is UP.> Oil does NOT flow uphill. If you use an aftermarket compressor with the X> down, you will starve the front bearing of oil. It may last a week, amonth,> 6 months.... depends on the quality of the bearing they put in. "I have received feedback on that information confirming that it isbasically correct. That DOES NOT Mean that if you mount an R-4 upsidedown, it will fail prematurely - only that it is much more likely tofail prematurely if you mount it upside down.I have had many people dispute this and tell me that, "I mounted mycompressor without an X on it and it's still working 10-15 years later.No argument, but there really is a reason why Mercedes marked theircompressors and most of the guys I've spoken with that do this for aliving (and don't want comebacks) insure that they use compressorsconfigured to work on a Mercedes.Marshall--Marshall Booth Ph.D.Ass't Prof. (ret.)Univ of Pittsburgh School of Medicine[EMAIL PROTECTED]

So is there a way, a DIY'er like me to rotate the cover 180 deg. so the "X" mark will be on top and configure the AC comp. for Mercedes, just like clocking a Saab alternator.

The AC compressor that I currently installed right now was bought brand new from Advance Auto 3 years ago and still working great, blowing cold air, no noise and no issues right now but it doesn't have an "X" mark but it has an embossed "triangle" mark just like an arrow head at the 6 o'clock position, which means that if this "triangle" is the equivalent of the "X" mark that is supposed to be on top, then my compressor is bound to starve with oil and seize up anytime soon because it is clocked at the bottom..

leathermang · #4 07-08-2010, 02:49 PM

What if ' triangle' symbolizes the ' down position' instead ?
I would think more research would be needed....

85chedeng300D · #5 07-08-2010, 02:58 PM

Quote:

Originally Posted by leathermang

What if ' triangle' symbolizes the ' down position' instead ?
I would think more research would be needed....

...or the "triangle" could symbolize an UP position??? who knows....

Anyway, this is a Factory Air by 4 Seasons PN: 58228

....anybody has bad or good experiences with this AC compressor used in a 617 Mercedes?

funola · #6 07-08-2010, 03:11 PM

Quote:

Originally Posted by thayer

Here is some information I found while researching the r4 compressor and it's uses on both GM and Mercedes. I found this fascinating.

Re: [MBZ] AC Compressor woes...

....The R4> compressor was originally designed for GM cars with the compressor mounted> on top of the engine. The X and the inlet/outlet port is UP. Mercedes used> the compressor but rotated it 180 degrees and mounted it under the engine.> This put the ports DOWN. Then they rotated the front cover so the X is UP.> Oil does NOT flow uphill. If you use an aftermarket compressor with the X> down, you will starve the front bearing of oil. It may last a week, amonth,> 6 months.... depends on the quality of the bearing they put in. "I have received feedback on that information confirming that it isbasically correct. That DOES NOT Mean that if you mount an R-4 upsidedown, it will fail prematurely - only that it is much more likely tofail prematurely if you mount it upside down.I have had many people dispute this and tell me that, "I mounted mycompressor without an X on it and it's still working 10-15 years later.No argument, but there really is a reason why Mercedes marked theircompressors and most of the guys I've spoken with that do this for aliving (and don't want comebacks) insure that they use compressorsconfigured to work on a Mercedes.Marshall--Marshall Booth Ph.D.Ass't Prof. (ret.)Univ of Pittsburgh School of Medicine[EMAIL PROTECTED]

The OEM Mercedes GM Delco compressor in my 83 300D has the inlet/outlet ports and the X on top. It is not mounted upside down as the above suggests.

thayer · #7 07-08-2010, 03:12 PM

Quote:

Originally Posted by 85chedeng300D

...or the "triangle" could symbolize an UP position??? who knows....

Anyway, this is a Factory Air by 4 Seasons PN: 58228

....anybody has bad or good experiences with this AC compressor used in a 617 Mercedes?

I've heard them referred to as 4 "seize"ons.

However, if the above information is correct then we have now found out why they are short lived.

BUT!!!!!!!!!!!!!

My remanned advance auto compressor's main seal blew...that is a rebuilder defect. So, it may be that all the cards are lined up against you on a rebuilt r4. My previous ebay comp was working fine when I showed up to go back to r12 and when we evacuated (I use the term loosely) the 134 we found grey dust/gunk in the lines. That puppy wasn't long for the world.

Yak · #8 07-08-2010, 08:10 PM

I suppose this could be true, or it could be Internet hearsay.

No disrepect to the good doctor, but according to a post on ACsource.net, the original source was "Karl on USENET".

And since Funola currently has a compressor disassembled in another thread, let's ask him.

engatwork · #9 07-08-2010, 08:28 PM

There were some pictures from the inside of one of these units floating around here a few years ago.

vstech · #10 07-08-2010, 08:37 PM

I'M thinking since the r4 has no sump, there should be no issues with orientation. thayer has read that there are oil passages for the compressor that need to be rotated down on a true GM R4 compressor. I hope funola can confirm the oil passages with the torn down compressor he's working on.

funola · #11 07-08-2010, 09:38 PM

Quote:

Originally Posted by vstech

I'M thinking since the r4 has no sump, there should be no issues with orientation. thayer has read that there are oil passages for the compressor that need to be rotated down on a true GM R4 compressor. I hope funola can confirm the oil passages with the torn down compressor he's working on.

The "oil passage" is a hole in the casting on the cover plate directing oil to the main shaft roller bearing. The location of the hole is marked on the outside of the plate with an "x" or a "o" (unconfirmed) so you can see it's orientation. It makes sense for the hole to be on top so that oil mist will gravity feed into the hole and lubricate the bearing. If the hole is on the bottom, the bearing may not get enough lube and fail prematurely.

netboy · #12 07-09-2010, 09:28 AM

Just opened my brand new Behr a/c compressor and all the markings are inverted. Looks like it has a sight gage of some sort with a view window that should be on bottom but will be on the top as it would be installed on a MB.

leathermang · #13 07-09-2010, 09:41 AM

Netboy, you need to go to the user controls and place your car model , year, etc into your signature...

netboy · #14 07-09-2010, 09:57 AM

Sorry about not specifying which car. It is for a 1981 300sd.

I have a '83 and '81 SD, an '85 D, a'83CD, and a '91 350sdl. Cheap transportation for my teenagers. I can't keep them straight, but i'm trying to keep them running

leathermang · #15 07-09-2010, 10:16 AM

Can you post pictures of your new compressor ? Include closeup of that sight gauge...