AC o rings
 

Whats the location of them all and how many do I need?

Great question! I'll go one further- does anybody have a link to something that shows the whole ac system in an exploded view, or something similar?

Waiting on the first joke to be cracked along the lines of "Load one of them up with illegal, dangerous, unlawful, irresponsible, catastrophically cataclysmic refrigerants and we'll show you a view of an exploded ac system." :D

AC o-ring kits have a bunch of any size you should need for about $15 dollars. Locations? Cant say, but anywhere two lines or parts meet. Pretty easy to tell. I have replaced AC o-rings on entire systems many times.

Get a free subscription to the Mercedes-Benz EPC (Electronic Parts Catalog). It will show what you need, though it is still not always 100% clear what seals go where. Sizes of o-rings (seals) depends on model and even VIN within that model.

http://epc.startekinfo.com/epc/welcome.jsp

Never knew about this. Really helpful to know.

Richard

Cool. Good info for a newbie like myself.

a/c system is pretty straightforward.
compressor has two o-rings on the manifold. unless your compressor has been changed... then it could have spacers/manifold/god knows what else...
the big lines go to a fitting on the condenser that has an o-ring, out of the condenser there is a fitting with an o-ring, from there it goes to the dryer with an o-ring and three small o-rings for the sensors and the line out, from there it goes to the expansion valve with an o-ring, then out of the evaporator back into the expansion valve with an o-ring, then the large line has a connection in the firewall with an o-ring, and if you have a 123, another line with another o-ring, if not, then the line goes right to the compressor on a 126.
other systems will be similar.
also the R4 compressor has a valve on the back of it, with a snap ring, that could leak also, with an o-ring under it... if it's not leaking don't muck with it...

Will O rings from 134a work for 12?

yep. no issues with 134 o-rings

Sweet

Why has no one mentioned Nylog ?
I think the color does matter on that....

Well, I asked as the o rings in the current system are good, so I was wondering if they'd go with 12 too, i dont want to replace em lol

You want green o-rings. If you disconnect anything, you put new ones in! I was told to use a VERY small amount of silicone grease to prevent binding when coupling the two parts. Not sure if that is standard practice, but I had no issues.

the O-rings on the compressor are a no brainer, I just don't want to have to go back through the whole system to replace them all.