You’re right, if you have a line or cylinder leak downwind of the hand pump, the hand pump will do you no good. That’s why I’m glad my Glasair III has separate lines and hydraulic cylinders downwind of the handpump.

 

-----Original Message-----
From: Lancair Mailing List [mailto:lml@lancaironline.net] On Behalf Of Robert R Pastusek
Sent: Tuesday, January 29, 2013 12:11 AM
To: lml@lancaironline.net
Subject: [LML] Re: hydraulic pump/reservoir in IVP

 

Laurie Fitzgerald (Australia) advises that while the manual pump can compensate for an electric pump failure, it will likely only help you dump the remaining hydraulic fluid overboard in the event of a leak. I agree with this assessment…for leaks within most of the IV/IV-P hydraulic system. Laurie further advises that he’s working on an improvement. If he successfully figures this out, we’d be pleased to publish it to LML and LOBO followers.

 

Bob

 

 

 

Thanks Bob,

 

And that’s a great idea for the dip stick.  As I recall the overflow vent was called for in the plans and I have that feature.

 

John

 

 

John Barrett wrote:

 

Anyone know the capacity of the reservoir?  I measured the box roughly and got 6”X6”X6.5”.  Don’t know the displacement of the internal parts that go inside the tank.

 

An even more important question is how full to fill the tank?  All the way or some measurement below the top?

 

 

John,

 

I’d recommend you leave at least an inch of airspace at the top of the reservoir; 2” is better. This allows for thermal expansion and to accommodate any air that might get into the system. It’s also important that the tank be vented as shown in the building diagrams…for the same reason. The volume in the reservoir doesn’t change appreciably during operation of the gear and flaps. Also note that the tank has a pickup for the emergency extension hand pump that is lower than the normal pump pickup. This allows the emergency pump to draw oil for gear extension after the electric pump has pumped all it can overboard in the event of a leak.

 

I made a very simple “dip stick” for the reservoir by drilling the fill plug from the inside for a length of 1/8” aluminum pipe, and bonding the tubing in the plug with JB Weld. Then mark the dip stick for the max and min levels you’d like. Do this easily by crimping the tube gently to mark it with a pair of side cutters.

Works well…

Bob