I bought an S40-E which I believe to be a 1976 about a month ago. Got it for a steal but, of course, it has lots of leaks that we're trying to chase - mostly hydraulics. I think we have found the big ones but I have a question about a seemingly small leak from what I would assume is an uncapped pressure release valve on the left hand side of the lift just above the battery. The valve is connected to a tank with a fill cap but no dip stick - unlike the right hand side where there is clearly a hydraulic fill. I purchased an online PDF of the service manual that seems mostly complete. In the manual it calls that left hand tank a fuel tank. It is an LP lift. I'm wondering what this tank actually is. And what that valve is. Is the tank a receiver for hydraulics or fuel? Is it a tank for gas in what would have been a gas powered lift? For better or worse, there is definitely some hydraulic fluid in it currently. I appreciate any thoughts and / or advice.