High Pressure PS Hose O-ring

[tomblue01]

Doing a PS flush.
I think this o-ring has seen a few years.

A) What do I replace it with?
B) What type of material does this o-ring use? EDPM, Buta-N, Vitron...?

The metal tube OD --> ID for the o-ring I measured at 9.2mm / .36"
The o-ring thickness (in its squished state) I measured at 2.3mm / .090"

 

[tomblue01]

A thread here from years ago mentioned using a "Danco #6" o-ring, but the dimensions don't quite line up.

The 94-96 Truck Parts Catalog does not mention the o-rings. Only the complete hose.

 

[Ozymandias]

You can get these rings at the parts stores, I had to do that while I was exchanging the PS pump. No big deal.

 

[tomblue01]

The auto parts stores near me didn't know which rings would fit, but offered to sell the entire hose.

Desired material: FKM (Viton) or FFKM ((Kalrez) (highest temp & best chemical resistance) ($)) with a preferred hardness of Durometer 90. Both types hate brake fluid, fyi.
AS568 size "dash" 011. 5/16" ID, 7/16" OD, 0.07" CS (>1/16").

Those of you living up in the land of cold and snow may wish to use butadiene nitrile rubber o-rings, Buna-N, because they can have better cold weather performance. A word of caution: There's a range of variation within the Buna-N community. "Depending on its intended use, Buna-N can be customized with different mix-ins and accelerators." - https://www.technoad.com/buna-n-nbr/ What the article goes on to say is that if the Buna-N o-rings have been manufactured with the correct ingredients, then they can fit varying scenarios. So far as buying random Buna-N o-rings off of Amaz/Ebay, I caution against it unless their properties are clearly presented (which I found not to be the case. YMMV).

I bought FKM o-rings from McMaster-Carr (FKM and Viton are like "tissue" and "Kleenex", respectively. Similarly: "hex key" and "Allen key"). The Duro 90's were not available, so I picked the next highest at Duro 75. I'm not too worried about the hardness factor, especially after feeling them. I would not buy Duro 55 rated o-rings, though. High pressure lines want harder o-rings.

New & old, side by side:

 

[tomblue01]

A final thought regarding ordering from McMaster-Carr: The website assumes that you want overnight shipping. If you find you have a ridiculously high shipping & handling price, then ensure that you are not getting next day delivery!
I couldn't resolve the s&h issue through the inet (probably cookie related), so I called them. Excellent customer service. Issue resolved.

 

[GAmes]

tomblue01. I tok a look at the McMaster-Carr page and it appears the o-rings only come in packages of 100. If that's the case would you consider selling a few to me? I certainly don't need 100 but having 4 or 5 could come in handy.

 

[SAndreasen]

It’s an O ring pick one up at a farm store or heavy equipment dealer for 1 or 2$