Mailing List lml@lancaironline.net Message #44398
From: Bill & Sue <5zq@cox.net>
Sender: <marv@lancaironline.net>
Subject: Re: [LML] IVP accumulator question
Date: Wed, 10 Oct 2007 12:23:54 -0400
To: <lml@lancaironline.net>
HOLD ON DAN! Be very careful with the accumulator. Accumulators have what is known as a "precharge" probably somewhere in the neighborhood of 1000 psi. This charge will be in the top side even when the bottom side is at zero pressure. Make damn sure that you're not screwing out something with 1000 psi behind it. To remove the accumulator from the plane, you should just have to bleed the HYDRAULIC pressure to zero on the bottom side. No AIR bleeding should be necessary.  If necessary, the precharge should be refilled to the recommended pressure with nitrogen. Check with Lancair for the recommended pressure.  Hope this helps.
 
Bill Harrelson
N5ZQ 320 1,400 hrs
N6ZQ  IV  under construction
 
 
----- Original Message -----
From: Dan Reagan
Sent: Wednesday, October 10, 2007 9:02 AM
Subject: [LML] IVP accumulator question

Recently I have noticed that the hydraulic pump seems to cycle more than usual when the flaps are going into the down position.  Going down it cycles once every second for about 6 seconds.  Going up it cycles one time. 
 
I am trying to check the accumulator pressure but it looks like I am going to have to take the accumulator out of the plane to do this since the end cap which protects the schrader valve won't easily turn.  Before I started the disassembly process I thought I would get some opinions and advice on if there is a problem and what to do about it.
 
Also, with the hydraulic pump breaker pulled, the pressure in the accumulator will cycle the flaps to the opposite position but not much more.  My thinking is that the accumulator is not totally bad but just has low pressure.
 
If I remove the accumulator for maintenance, what air bleeding will I have to do?
 
Any advice and help would be appreciated.
 
Dan Reagan
IVP 450+ hours
Cincinnati
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