REFLECTOR: Hydraulic Fluid

Sid Knox sbjknox at earthlink.net
Sun May 24 00:29:30 CDT 2009


----- Original Message ----- 
From: "Chuck Jensen" <cjensen at dts9000.com>
Subject: Re: REFLECTOR: Hydraulic Fluid


> Okay, I need to add hydraulic fluid and the FBO is shut tight for the
> weekend...no 5606 available.  It was speculated that the automatic
> transmission fluid (ATF) is just a rebranded/repackaged 5606.
> Has people used ATF in their gear retract system?

> Chuck Jensen


For the first time in the eight years that I have owned this Velocity I had 
to replenish some lost hydraulic fluid.  I used ATF (Mercon IV ?) because 
that is what I have and I figured that a modern automatic transmission is 
far more complex and works far harder than the retract system.

For me, a greater concern is.... where did the fluid go??  I have never 
found signs of a leak but it obviously went somewhere.  Well, actually, I 
discovered the low fluid situation by what at first appeared to be a leak. 
After a flight during which I noticed that my pump would cycle briefly every 
two or so minutes (not normal) I found hydraulic oil on the belly.  Opening 
the nose cover, I found hydraulic fluid all over so there was no way to 
determine from where it came.  I checked all fittings for tightness, cleaned 
up the mess, and tied small scraps of rag around all the places where I 
figured it might be leaking.  Flew for about 30 minutes, landed and looked 
inside the nose.  Oil everywhere but none of the rag tell-tales showed any 
more than what was blown on them from the turbulence due to gear doors 
opening.  WTF??   I let it rattle around in my head for a few days and then 
it came to me.  The fluid was probably low and the pump was cavitating and 
building pressure in the reservoir and blowing fluid out the breather line. 
I added a few ounces of ATF (I have no sight-gage) and no more problem!

Sid Knox
Oklahoma

Velocity  173 RG  N199RS
Starduster  N666SK
KR2         N24TC
W7QJQ






More information about the Reflector mailing list