lml@lancaironline.net Mailing List Archive

Dennis, On the door seal. Your description sounds like a slow leak. Several things to check: you should have a 1-way valve in the system just downstream of the pressure pump. This keeps inflation air from back-flowing through the pump... Most pumps have a small amount of leakage built in to them, so the anti-backflow valve is important. Second, (CAREFULLY so as to not damage the tubing) pinch the pressure feed line closed as close to the door seal as possible and activate the pump. If it continues to cycle, your leak is between the pump and the clamp point. If it does not cycle, the leak is in the door seal itself. This one is a bitch to isolate, but you can do so by (again CAREFULLY) rigging jumper wires so you can inflate the seal with the door open. This will open the leak and you'll be able to hear it. You must be able to control the power on/off when doing this, as it's possible to literally blow up the seal if you over-do it, so some caution required. This is what I did to isolate a pin-hole in my door seal...and it took me a good period of time to find the hole, then somewhat longer to get it plugged. I was almost ready to replace the seal in frustration when I finally got some 3M RTV sealant in the right spot, and BINGO, no more leaks. My door seal pump does not cycle at all any more... Good Luck. Bob -----Original Message----- From: Lancair Mailing List [mailto:lml@lancaironline.net] On Behalf Of Denis Conkey Sent: Sunday, July 28, 2013 10:57 PM To: lml@lancaironline.net Subject: [LML] IVP Pressurized Door Seal and A/C Fans I know many of you have experience flying with the pressurized IV. How often should the door seal pump engage after the pressure is up on the Seal? Ours seems to have a very short cycle "on" about every 5-8 second. The pump runs a second or less when it cycles on. Not having experience with the pump, seems like the cycle time should be a bit more than that which might be indicative of a slow leak. We have checked for leaks in all our tube connections using soap bubbles and could not identify any leaks. What is a good way to check for leaks? Is it possible for the pump to be leaking internally? Any advice on this topic would be much appreciated. We have an air conditioner unit and the fans in the cabin that draw in the air are very noisy. They are 4 inch Attwood Turbo 4000 fans. These fans are estimated to be more than 5-6 years old but used very little. I noticed that Attwood has a Series II fan that might be quieter. Are there other options for fans that are not quite so noisy. These will drive any backseat passenger crazy and I fear will be quite noisy in the front as well. If you know of any other 4 inch fans that would be well suited for this purpose or if the Series II fans are better, please let us know. Thanks, Denis Conkey/Jim Thompson Lancair IVPT - N750PJ 805-402-6197 -- For archives and unsub http://mail.lancaironline.net:81/lists/lml/List.html