Intermittent P/S

[Kneale Brownson]

At 11:11 AM 01/10/2003 -0500, Phil Rose wrote:
>>At 9:00 AM -0500 1/10/03, Joshua C wrote:
>>I have never been inside the PS pump
>
>If you do go, be sure to take Raquel Welch along (you're probably too
>young to "get" that.) :-)
>
>
>>  but I would belive that it is possible
>>to cause foaming of the pentosin withouth a leak.  It would be through
>>cavitation, it is like when a motor boat has a bad prop, you get foam,
>>bubbles etc..but reduced power.
>
>Yeh, I wondered about that possibility too, but I suspect that the
>properties of hydraulic fluid (viscosity, surface tension, etc)
>greatly reduce that possibility, although I don't really know. I
>think an air leak on the low-pressure side of the pump is more likely.

Bernie says the pump can suck air around the seal for the pulley shaft.  I
suppose it also can suck air at the banjo bolts too.  I think hydraulic oil
cavitation can occur in large-volume systems like excavation equipment.