does the green a/c oil ring....
 

... look bigger or smaller when new -- compared to the old one you are replacing? Like radiator hoses, the new ones are usually smaller looking due to it not being stretched yet . But does the same principle apply to A/C green O-rings? I was changing my exp valve and the new ring seems to be smaller in thickness but the same diameter or should I say prettty darn close to the old one.Not to mention a little darker in color as well.

I just want to put the wrong one, esp. if I accidentally put the wrong one in the evaporator area..Too big of a job make such a small mistake.

Try to work from published o-ring sizes if you have that data. In the absence of specified data, make sure you're looking at a stash of metric o-rings when trying to make a match.

I got about six or eight different ones with my expansion valve for the TE -- I used the ones closest in size. My old ones were black, though, and soft, not compatible with either the PAG oil or the R134a.

If they seal, you are fine.

Peter

I called the dealership and they told me that qoute"there is no specified mbz part number for the o-rings. Therefore, if it is the right size or very close, that's the right part for it."end quote And they also said that old(used ) o-rings are usually "swollen" compared to brand new ones. That means the new ones should look a bit slimmer. Thanks for the reply guys

If you can't get the specifications, you'll have to go by feel. Sometimes you can tell if the o-ring is too big or too small by how it slips together. Make sure you install the o-rings wet. Use refrigerant lubricant to wet the seals.

royally confused
 

... I called the dealership (again) today to inquire about the o-rings for the heater core this time. Now they have a part number for it and it's $2.50+ for one and I need 2 or 3. But the funny thing is I asked this different person again about the green o-rings and he came up with a part number. And they are also $2.00+ / o-ring.

Question: Is it worth it to get these MBZ part numbered o-rings for both HC and EVAP/exp.valve?? If not , where can I get the heater core rings now? I already have the green rings. I'm just afraid that the non-MBZ part will not last as long as the of-the- counter part or I'm just over reactiing due to this 12 hr. removal time that I have spent on it? Lord knows how long it would take to put it all together..sorry for the gripe :rolleyes:

Well, I went ahead and called the person that knows--Phil
And he hooked me UP!!!:cool: Thanks Phil