Parts Catalog Accessories Catalog How To Articles Tech Forums
Call Pelican Parts at 888-280-7799
Shopping Cart Cart | Project List | Order Status | Help

Go Back   PeachParts Mercedes-Benz Forum > Mercedes-Benz Tech Information and Support > Diesel Discussion

LinkBack Thread Tools Display Modes
Old 02-29-2008, 10:29 AM
Registered User
Join Date: Nov 2007
Location: Snohomish, Washington
Posts: 47
AC oil again

Please foregive the redundancy here, but my search of the archives did not answer my question:

How much and where do I put oil in a vacated ac system with new compressor? 1981 300D with R4 compressor.

My guru is suggesting a bunch in the compressor (then turn by hand 12 times) and some in the receiver-drier. He also says to use ester oil as this is going from R12 to R134a. Doesn't seem to know anything more specific for an old MB.

So, after reading the archives, I am only more in doubt: one thing in consensus seems to be that adding too much is bad. But i am not clear on what is too much.

The gist of what I've read seems to suggest 4 oz in the compressor and 4 oz in the receiver drier. Does that sound right?
1981 300D 202K daily driver
Reply With Quote
Old 02-29-2008, 10:58 AM
sailor15015's Avatar
Reverse lights! Score!
Join Date: Apr 2005
Location: Norman, Oklahoma
Posts: 1,184
That sounds right. You need to turn the compressor first because its new and has no oil in it. I've heard 6-8 oz and when I redid my system, I used 4 in the comp and 4 in the dryer. If its not too late, go with synthetic oil. That way there's no need to worry about specific oils for specific refrigerants, and its got to be better for the compressor and the R4 needs all the help it can get. BTW, I redid my system two summers ago, with a rebuilt R$ and, you guessed it, I'm having to do it again right now because the rebuilt comp gave out. Don't cheap out the $60 or so you'll save with a rebuild. Its not worth the hassle.

1984 300D 225K
1985 300D Donor body
1985 300D Turbo 165K. Totaled. Donor Engine. It runs!!!
1980 300SD 311K My New Baby.
1979 BMW 633csi 62K+++? Dead odo
Reply With Quote
Old 02-29-2008, 11:22 AM
vstech's Avatar
Join Date: Mar 2006
Location: Mount Holly, NC
Posts: 26,274
also, be surre surre surre that you have totally blown and flushed all traces of mineral oil from the evaporator, condenser and all freon lines. also replace the expansion valve and reciever/drier. now, once you have done all that, buy some real R12 and put it back the way it was. don't cheap out, 134a is junk in this system. it will not cool well, it will kill the compressor. just go back with 12.
John HAUL AWAY, OR CRUSHED CARS!!! HELP ME keep the cars out of the crusher! A/C Thread
"as I ride with my a/c on... I have fond memories of sweaty oily saturdays and spewing R12 into the air. THANKS for all you do!

My drivers:
1987 190D 2.5Turbo
1987 190D 2.5Turbo
1987 190D 2.5-5SPEED!!!

1987 300TD
1987 300TD
1994GMC 2500 6.5Turbo truck... I had to put the ladder somewhere!
Reply With Quote
Old 02-29-2008, 11:25 AM
rrgrassi's Avatar
mmmmmm Diesel...
Join Date: Jun 2006
Location: Royse City Tx
Posts: 4,872
You need to use either the GM specified oil, or get the BG frigi-quite oil. I'm using the BG stuff. I got it from a local rep for $11.99. Much cheaper than $39.99 through Diesel Giant.

70's SPM #5608 Fairmont A-4 MOW car

06 VW Jetta TDI 210K miles

03 VW Golf TDI 5 speed 372K Miles

RIP--Lost in fire...82 300D 322K was My Daily Driver-On the search for a w126 now...

90 Dodge D250 5.9 Cummins/5 speed. 350K
Reply With Quote


Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On
Trackbacks are On
Pingbacks are On
Refbacks are On

All times are GMT -4. The time now is 03:01 PM.

Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2019, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2018 Pelican Parts, LLC - Posts may be archived for display on the Peach Parts or Pelican Parts Website -    DMCA Registered Agent Contact Page