It's still nice to know why. I know the tow truck i just bought doesn't seems to do it, and it's other wise the same, athought the po replaced the hyrovac unit recently. I've got a bad feeling that's what it is.

Still strange that there's nothing on the ground - that's alot of brake fluid. Well, the truck's for sale, so I've just got to get it to work well enough to get up here, then sell it.
~John