I think that this question has been answered already, but to summarise depending on the insulating strength vs. temp(easily checked with OEM) the hydraulic oil may be acting as the dielectric medium between the carbon brush and the slip ring, and then rapidly breaking down to become a conductor...
Thanks for the info!
Sorry about the vagueness. The terminals (24VDC about 7mm diameter) are mild steel that are mounted on a Perspex block inside a stainless steel enclosure (about 25cm in diameter. However the stainless steel enclosure over time has moisture ingress which causes seawater and...
I was looking for a sealing material that is non-conductive and is both impervious to diesel and salt water. The sealant is to be used on Stainless Steel, Perspex and mild steel.
