I am properly converting the AC on my 92 from R12 to R134a and I just picked up a new expansion valve today. The kit came with new metal crush gaskets and also O-rings. Why are there o-rings, I can not recall anywhere in my lines where O-rings are used except for at the compressor (TIII) Can someone tell me what these o-rings are for? Are these used on a different car that uses different lines?
Here is the part I picked up today:
https://www.oreillyauto.com/detail/b...on+valve&pos=0

Thanks