Which o ring material is best for hydraulics?

[STx]

I need to replace an o ring on my hydraulic system and have both rubber and viton (fluorocarbon) on hand. Which is better for this application? I'm leaning towards the viton this time. They're $$$$ but, I've already got them.

 

[GeneV]

I would think just the standard nitrile rubber ie buna-n.

 

[SBCO1]

Buna bounces,viton does not:
Simple test, need metal rod about 12" or so, or something similar,brass,copper,etc. Put o-ring in question under one end of rod pin the other end down with your finger raise end over o-ring then let it drop if it bounces it's buna,if it hits with a dead thud it's viton.

 

[Midniteoyl]

Buna bounces,viton does not:
Simple test, need metal rod about 12" or so, or something similar,brass,copper,etc. Put o-ring in question under one end of rod pin the other end down with your finger raise end over o-ring then let it drop if it bounces it's buna,if it hits with a dead thud it's viton.

Thanks for that, but not what he was asking.

 

[STx]

Thanks for that, but not what he was asking.

LOL, it's all good.

I ended up using the Viton, I've had the traditional rubber fail twice here so I figured I'd try something different. We'll see how it holds up over time.

 

[FTG-05]

McMaster-Carr chart; the temp difference may cause the Viton to be slightly more robust, I would think.

 

[oldnslo]

What is the application? Viton will with stand higher temperatures and different fluids than nitrile or Buna - N. Seal failure is usually a result of their being to large of a gap between metal mating surfaces not the seal material itself.

 

[crazyal]

If you think Viton is expensive price out a compound like Kalrez. I would go Viton over rubber everytime when dealing with hydraulics. Rubber breaks down much quicker.