O Rings on a/c compressor? - PeachParts Mercedes-Benz Forum

Box-a-rox · #1 07-31-2002, 09:48 AM

I ordered a new a/c compressor and dryer for my 83 300sd. I removed the old compressor and it has o rings for a seal. The new compressor looks like it takes something flat like a garden hose washer. The seal area is larger and flat the o rings are to small. The new compressor didn't have the new seals. Can you get these seals from a local NAPA parts store? Thanks, Ken

jobah · #2 07-31-2002, 10:10 AM

It should still take o-rings. The o-rings are available at many auto parts stores (it is best to get a wide assortment). Make sure that you get o-rings which are intended for use in AC systems. The ones that are available for 134 systems are likewise compatible with the ones available for r-12 systems.

I would replace all of the o-rings which are readily accessible. As your car is approaching 20 years, the o-rings will generally be quite old and it is better to replace now than to fill the system only to find that a $.30 o-ring is leaking.

Also, if you had a compressor seizure, I would replace the expansion valve.

Box-a-rox · #3 07-31-2002, 11:04 AM

There is no way I can get an o ring in there the machined area is flat and too wide for an o ring. I hope I didn't get the wrong compressor. Has any one seem the newer GM R4 compressors?
It looks like it take a large flat washer something like a garden hose washer.
I didn't burn out the compressor it just had a bad leak in the body of the compressor so I am replacing it. Ken

leathermang · #4 07-31-2002, 11:11 AM

You are probably looking at the flare portion of the fitting... the o ring goes on the other side of that.. on the back side of the ridge, and in front of the "nut" on the line...

call these guys,,,, they are very good....

http://www.caawparts.com/

They just fixed me up on the 240 and my ford pickup... they know pretty much everything... Greg

#5 07-31-2002, 11:40 AM

I think it is a safe assumption that this is an R4 compressor. The later, replacement R4 compressors do use a sandwich or some other type seal. There are two different styles besides the earlier o-ring models. You just need to take the compressor to your local automotive air conditioning shop. Most communities have one that does service AND sells parts. They will surely have the later type seal that you need. The manifold that is on the car will still work, it is a flat surface, so it doesn't change.

Get the new seals and put a little Nylog lubricant on them. If you don't have any, use refrigerant oil.

Good luck,

Box-a-rox · #6 07-31-2002, 01:44 PM

Thank You, I called the supplier I bought it from and it should have had the new seal in the box. In addition when I looked closer at the ports it looks like the compressor was dropped and the lip on one of the ports is bent. I am going to try and return it and get another comressor. Thanks again. Ken

the_good_fellow · #7 07-31-2002, 02:06 PM

New A/C Compressor would have two packages of seals in the box. One package contains a green, a red seals and two aluminium adaptors for suction side I believe. For 300 SD use the green one on suction side and the bigger one of two in the other package for the other port. After you tighten the 15MM nut you should see a 1-2 mm space between the compressor and the hose mounting plate. make sure they are even on both ends.

MVK · #8 07-31-2002, 09:56 PM

Make sure its new and not a rebuilt R$. If you are buying the rebuilt R4, you might as well throw your money in the garbage.
Tons of failure with rebuilt R4.

Also the green or blue o rings are the way to go they are good for both r134 and r12

MVK

jbaj007 · #9 07-31-2002, 11:15 PM

Pull up your car and the compressor on the FastLane menu (on this page right above you) and read the description of the sealing rings for the STEPPED port R-4 (which is what you have). Follow what the_good_fellow said.