Notes on AC Compressor Replacement - Turning and adding oil - PeachParts Mercedes-Benz Forum

rhodes2010 · #1 06-29-2006, 01:03 AM

I installed a brand new and dry (no oil) compressor onto my 300D.
Put it in place and used the yellow (steel color) washer on large line (low pressure and the thicker Green washer on the high side.

The low pressure line has a fitting conveniently located above the compressor
where I was able to set a small funnel and add the 4 ounces of oil.

I took two 1/4 inch female spade electrical connectors and attached to two pieces of 3 foot wire (16 or 14 guage). Attached these to the compressor magnetic coil and to my battery charger (set the charger to 2 amps at 12 volts).

Now I was able to use a strap wrench (Harbor Freight cheapo) to turn
the compressor clockwise to circulate the oil.

It is all buttoned up and has been drawn down with vacuum and is sitting overnight. Tomorrow I will add the freon.

I used Harbor Freight vacuum pump and my compressor to pull the vacuum.

So far so good.

Oh, and one more thing. I replaced the AC Evap in the interior with one from the 81 300D (this is a 1980 300D). Well, they are not exactly the same size and it required a marriage of the three major pieces that make up the housing for the AC evap. Two lower parts from the 1981 mated to the 1980 upper section.

And I determined that replacing the older ACC II system with vertical buttons and the heater servo underhood with a newer version using the horizontal buttons would have required the wiring harness to be pull and separated probably up to the fuse box. This subject has been talked about, and in my opinion is not practical - even given unlimited amounts of time and parts.

Diesel Giant · #2 06-30-2006, 08:47 PM

If you need some help on the A/c check out the pictorial

http://dieselgiant.com/repairyourac.htm

leathermang · #3 06-30-2006, 09:09 PM

Did you install any into the Receiver/dryer ... or your new evaporator ?
How much total oil and what kind do you plan on using ?
That does not seem to be enough oil. And only putting it into the compressor may allow too much time before it gets circulated back to the compressor...
Usually the instructions when replacing items like the evaporator include measuring the oil which comes out of the old one and putting new oil into the new one.

rhodes2010 · #4 07-01-2006, 12:23 AM

I followed the DieselGiant guide as listed and split the oil between dryer and compressor. The book (manual) calls for 8.10 ounces.
I used an 8 ounce bottle.

Some listing of similar body called for as low as 5.8 and some say 7 to 9 ounces.

A little leeway.

I would be curious what the downside is to too much oil and how
someone could tell if they had too much.

Drove it to work today, on the way home it was 108 fahrenheit where I live.
Saw the temp gauge on the car go up to just over 100c and got a little worried.
Of course I was cool inside and did not realize it was hot until getting out of the car.

One More Thing (OMT): I am gong to give my first endorsement...
Techchoice Parts 3051 FM 663
Midlothian, Texas 76065
(972) 723-0112

http://stores.ebay.com/TechChoice-Parts-A-C

I do not want to take anything away from our beloved sponsor and I shop here first, always.
During this AC ordeal on my two cars I shopped several sources and was pleased with all of them.
Not one bad experience. But the guys at Techchoice will really go out of their way and give
tremendous personal service. (they have flush kit, O-ring kits, oil, compressors).

Hope you all don't mind me putting in a plug.

leathermang · #5 07-01-2006, 07:25 AM

"(manual) calls for 8.10 ounces.
I used an 8 ounce bottle. Some listing of similar body called for as low as 5.8 and some say 7 to 9 ounces. A little leeway."

Yes, you should be good in that range and it split out in the system to start off...

"I would be curious what the downside is to too much oil and how
someone could tell if they had too much."

There are serious downsides to too much oil... If you use the search with my name as poster you should be able to find them.

"Of course I was cool inside and did not realize it was hot until getting out of the car."

That is what it is all about... hope it lasts ten years.

"One More Thing (OMT): I am gong to give my first endorsement...
Techchoice Parts 3051 FM 663
Midlothian, Texas 76065
(972) 723-0112

http://stores.ebay.com/TechChoice-Parts-A-C
But the guys at Techchoice will really go out of their way and give
tremendous personal service. (they have flush kit, O-ring kits, oil, compressors)."

That is great to know. You could also post that in the ' good shops' category on this site...I have also had that kind of help out of Carlisle Auto Air in San Antonio... in Texas automobile AC is a very serious subject.