Lorn, I have seen this too. One thing I have noticed is this usually happens when it is cold either due to altitude or season. The low side pressurizes only when the cabin heater is on. I told that to somone and they thought I was an idiot. The next time I took that same guy flying I prooved it to him. Weird! My airplane is VERY well insulated. The only thing I can come up with is that the heater is heating up the hyd system and causing the pressure to rise much quicker than when it is off. Turn the heater off and the low side stops creeping up. Go figure.. Randy Snarr
Lorn H Olsen <lorn@dynacomm.ws> wrote: I can set my plane on jacks for days and have no pressure leak. I can fly for hours and have no pressure leak. But if I fly high,
where it is cold, every hour the pump will run for 1/2 of a second (about 300 lbs). The reason for this is that the high pressure side has leaked about 300 lbs of pressure to the low side (or gone done because of the temperature). Most of the time that I fly high for more than 3 hours, the low pressure side has increased enough to stop the pump from running when I put the gear lever down. At this time, I open the dump valve for just a second. The pressure in the low side goes down and the pump comes on.
I believe that our activators leak more when cold. Or, it could be that the high pressure side gets so cold that it needs more pressure and the low side also takes the pressure without relief? -- Lorn H. 'Feathers' Olsen, MAA, DynaComm, Corp. LNC2, FB90/92, O-320-D1F, 1,300 hrs, N31161, Y47, SE Michigan
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