Several of our guys (including me) have junked our mechanical pressure switches and moved to solid state adjustable switches.

 

http://www.automationdirect.com/adc/Search/Search?searchquery=PSD25-OP-5800H&cmd=Search&fctype=adc.falcon.search.SearchFormCtrl&TxnNumber=-1

 

 

-----Original Message-----
From: Lancair Mailing List [mailto:lml@lancaironline.net] On Behalf Of Don Gordon
Sent: Monday, February 07, 2011 7:45 AM
To: lml@lancaironline.net
Subject: [LML] LNC2 Hydraulic Landing Gear Pressure Switch Wear Issues

 

I have recently replaced both my high pressure and low pressure switches in the hydraulic system for the landing gear.  These switches began to have trouble providing a positive and discrete on/off event when the hydraulic pressure reached the prescribed limits.  I began to hear strange crackling and static noises in my headset just prior to the hydraulic pump running (though it would just run for a fraction of a second to re-pressurize).  These strange sounds in my headset began to occur longer and longer prior to the pump tripping on.  I also began to notice some other odd electrical issues with the aircraft.  Finally, I began to suspect these switches were faulty are replaced both of them.  The problem went away and so did my electrical issues I experienced.