2003 A/C compressor replacement


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I have a 2003 T1N with a single A/C compressor that runs both front and rear A/C systems. The compressor is leaking a lot of fluid so the system won’t hold a charge. I had it working for a day after getting it filled by a shop, but I UV-traced the leak to the compressor (which I installed, and probably did a bad job of, plus it was an Ebay rebuild). It seems that the fluid is coming from between the clutch pullies and compressor body. I guess the seal on the input shaft is bad?

I want to buy a brand new compressor. Europarts-SD is about $500 or so, and one from RockAuto is around $280 for a Denso w/clutch assembly. Will I be okay with one from RockAuto? Note that my 2003 is a Freightliner, and on RockAuto I’m looking at the Dodge section since they don’t list any A/C compressors for Freightliner Sprinters. Europarts mentions something about Auto Temp Control, which I don't know if I have (http://store.europarts-sd.com/accompressor-frontnew2002-2006.aspx)



Own a DAD ODB2 Unit.
I think the auto temp control is that sensor between the knob that selects where you vent the air to and the button you enable (turns on the red led) the AC. All US Sprinters have it that I am aware of.

The 2002/2003 Freightliner parts = 2003 Dodge parts (in 99.9% of the cases - get the parts manuals to verify that. The 2002 versus 2003 have a few minor differences, but the 2003's should be the same, except for trim and related items).
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Bob of QF

New member
I would agree with your diagnosis that the shaft seal is a goner.

However, I'm not a fan of new parts like this, unless you get a major branded replacement part (such as Bosch, etc). I prefer to get a quality rebuild part instead-- I've had brandy-new out-of-the-box parts fail (or be faulty) immediately after purchase-- but, always, after it's been installed.

Sure, it's warranted, so what? I have to remove the darn thing again, take it back to the auto parts store, and hopefully they have another of that item in stock... many auto parts stores only keep one of each on obscure things.

Whereas a quality rebuilt item has the distinction of being inspected, each and every one, by a quality technician. You cannot say the same for a brand new part, which may or may not have been tested at all...

But that's just me-- I hate R&R on the same part immediately after having done it once already. The key is quality rebuilder-- one that stands behind their rebuilding process with a nice fat warranty. Or even better? A local shop who specializes in rebuilding whatever it is you want rebuilt. I found one here, that specializes in alternators & starters; you can either exchange your old one for a newly rebuilt, or if you can wait? Have your part quality rebuilt in a few days.

That and a cuppa coffee will get you the local news at your local watering hole... and not much else. <big grin>


In full disclosure? I should note that I service home and business A/Cs and furnaces for a living. And about a year ago, I had a leaky A/C compressor on my little GM Caviler. I thought to myself, how hard can it be, to replace the seal? I can rent for free the tools to pull the clutch, and re-install them, so long as I'm buying replacement parts from the same auto parts store-- basically, their tool deal is this: you "buy" the tool for your use, knowing it's used, but in good condition. If you return it within a few days, with all the parts intact? (and keep your receipt) They will happily refund your entire "purchase" price of the tool.

So armed with a clutch removal tool, a clutch re-installing tool and a gizmo that was supposed to let me install the seal without damage, I proceeded to "fix" my compressor myself.

Did it work? No. Was it easy to remove & replace the clutch? Certainly! The tools worked flawlessly. Did I take especial care in replacing the seal? Yes, yes I did-- the problem, I think, is that it was not only the seal that was worn, but the shaft too, and the new seal would not seat against the old, worn shaft, so it leaked slowly. (dye confirmed).

I ended up junking it, and buying a quality rebuilt compressor assembly-- clutch and all. (although you can buy just the compressor, and re-use your old clutch if it's in working order)


New member
You're right about quality parts, etc. However, both Europarts-SD (who I trust) and RockAuto sell the Denso A/C compressor, so I think it's a legitimate replacement part. I think it's made it Japan, too, which gives me some comfort.


New member
I get lots of stuff from Rock Auto, including Sprinter stuff. There should be nothing wrong with a Denso compressor, they make lots of them for various vehicles. Some car components are specialized, but I think in the case of an A/C compressor, they are more commodity and Denso makes many OEM units.



New member
Welp, bought the brand new OEM Denso compressor from Rockauto. Only came with an o-ring for the smaller of the two fittings, so had to reuse the larger one. Still in good condition, fortunately. And it's not a standard size so I couldn't have used a regular o-ring. Not sure where you've even get it, honestly.

The compressor came pre-oiled, and I confirmed with RockAuto who confirmed with Denso that I don't have to add any PAG 46 oil (ND-OIL 8). Still a bit worried that the axial seals will leak again. Just paranoid, I guess. That's what happened to my system last time, but the compressor was a rebuild and had been sitting in a box for a long time, and I didn't properly spin the clutch before installing. Did it this time around.

Also bought a replacement drier from Rockauto. That came with both o-rings which was nice.

Got everything bolted up and the system was charged earlier today. Blows nice and cold, but that's what it did the last time I got a re-charge on the old rebuilt compressor. Axial seals started leaking for the aforementioned reasons I assume. I'll just keep running it over the next few days and see if any leaks crop up.


New member
I have a problem not sure if anyone can help. I am repairing a line on the rear a/c and upon completion I found that the rear a/c compressor is not bolted or have any brackets holding it in place. Someone had work on it and for some reason they took the brackets out and never replace it, and now I cant get a belt on with enough tension on it. it seem to be missing a pulley as well. the bracket that the rear a/c is mounted on ran behind the front a/c compressor the bolts was remove and the rear a/c compressor and left hanging there being kept in place by the front a/c compressor. What I need is a diagram or a photo of a rear a/c mounting brackets to reattach the compressor. I have already test it and it works fine just need to find a diagram.

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