So I built a hydraulic pump today

[RCP57]

I've been messing with this(big mess, oil everywhere) a bit lately and I need some advice on the shaft seal. I've got the pump to produce around 12bar or 175psi without any trouble but the o ring(now 2) on the shaft can't take the pressure. I have tried standard rubber, Viton and harder rubber with no success. Does anyone know what the manufacturers use on this style pump? I'm trying to seal the 1/8 motor shaft. Pictures of any working set ups would be nice to see too!

Thanks, Reg

[Jw.]

What kind of o-rings are you using?

Have you looked in to square type o-rings? I believe this is the type they would be using on these pumps. Have anyone taken apart a Jung pump on here? I would be interested to know as well.

Similar to these...
http://www.theoringstore.com/index.p...ndex&cPath=700

[Jw.]

This might be of some help.

http://www.rlhudson.com/O-Ring%20Boo...g-dynamic.html

Look at rotary seals and table 53. It lists dimensions for a 1/8 shaft using a round style o-ring.