Again, it's a simple system. When the up button is pushed, the solenoid is opened, the pump started, and fluid under pressure raises the window. When the button is released, the solenoid closes and the window stays where it is. When the down button is pressed, the solenoid is opened and the spring pulls the window down and pushed fluid back into the resevoir. One hydralic line only to each window. Kerry --- gimpineer@xxxxxxxx wrote: > > On Tue, 25 Jun 2002 10:51:51 -0700 "Dick Benjamin" > <DickB@xxxxxxxxx> > writes: > > The pressure in the system is about 250 PSI > (assuming this is the > > same pump > > as used by Packard). Remember that the solenoid > valve has to > > resist > > pressure in either direction - this may not be > what the ones you are > > looking > > at are designed to do, > > A few thoughts about solenoids. > How is the hydraulic circuit arranged? Are there > two solenoids, one to > open (feed) and one to close (bleed)? If not, how > is the pressure > relieved to close window? Is it a multi function > solenoid? Is there a > supply line only or a supply and return line? Does > the pump run > continuously, cycle to maintain pressure or cycle > with the window piston? > > If the valve is not just the right capacity (Cv) it > could work too slowly > or slam open and closed. If you don't know the > exact size, I would > suggest that you go a little large and pipe an > adjustable flow control > valve in series. This is just an adjustable (and > inexpensive) > restrictor. It can be adjusted for smooth > operation. It should be > available from the same vendor as the solenoid. > > Inquiring mind wants to know. > > 4 - Toes > >