89 5.0 AC help - O rings

[GKforce]

I found my leak with the help of my HVAC buddy - the Oring connection near the firewall where dthe line connects. I picked up some No. 8 rings that look like the same size as the old ones (just a bit skinnier) but I cant seem to get get the line to reconnect. I am trying to avoid damage by not pushing too hard.
Does anyone know if that is the correct size? He told me that they may be the correct diameter, but the wrong ring material thickness.

Thanks for any help.
(I tried to search first)

 

[hatchback88]

i would say get the exact size if you know anyone at a local garage that does ac repair they will have a kit with all the sizes and as far as getting it to lock back on, the seal may be the problem or check the locking tabs on the line sometimes they dont spring back like they should

 

[GKforce]

Sounds like good advise on the tabs.
I am working out of town now, only have sat's to work on the car, will check that this weekend.
Keep the info comming please.
Thanks