A/C O rings

[68 CUDA FORMULA S]

I was wondering if there are O rings that are made just for A/C or can I just go up to the local hardware store and get an assortment of different size ones? I would like to replace all of them while I am hooking up these lines on this 74 Scamp. If they are A/C specific and anyone knows a place that sells them please let me know where.
Thanks
Bob

 

[Woods74]

Yes, A/C Specific, go to Rockauto or Amazon, probably eBeg too.

 

[68 CUDA FORMULA S]

Thanks I'll take a look.
Bob

 

[Pete in NH]

Hi,

They are A/C specific especially if using R-134A. For R-134A systems you want HNBR material O rings, they are usually green in color. Your local auto parts store should have assortment kits. Take the old ones out of the system, go to the store and match up the sizes.

New O rings should be installed coated with a little e 525 A/C mineral oil, never dry. You can also use an A/C O ring lubricant like blue Nylog for an R-134A system.

 

[68 CUDA FORMULA S]

Thanks Pete.

 

[65 Dartman]

Hi,

They are A/C specific especially if using R-134A. For R-134A systems you want HNBR material O rings, they are usually green in color.

How about if using R-12?

 

[mderoy340]

Autozone has an assortment pack of the green ones and they work on 12 and 134. As mentioned before lube with AC mineral oil. If you don't have the AC oil a little bit of vasoline works fine.

 

[BillGrissom]

Harbor Freight has a kit of HBNR O-rings (green). BTW, HBNR has also come in blue and red. The industry is trying to standardize on green, since has been typical in after-market. If R-12 or HC (Duracool, Enviro-safe), you can use Nitrile/Buna-N (black), but better to stay green just in case R-134A someday (to be discontinued) or the new HFO-1234yc (compatible?). Viton (brown?) is better than nitrile for most things, but haven't heard of using it in AC. I don't know what O-ring if they change to CO2, but that will be 2000 psi so wouldn't work for your system anyway.

Are you re-installing used hoses? If so, I would change the rubber. Any AC or hydraulic shop should be able to do so. I have hose and a Master-cool crimper, but you could even buy hose on ebay and Oeticker stepless crimps. You don't need the crimper pliers if you have a nail puller (even the cheap Chinese one). Can also use screw hose clamps (Breeze smooth ones are best) but the Oeticker crimps look better and can use 2 to be extra-safe. After-market AC in the 60's used screw hose clamps (my 65 Newport) and they didn't leak.