Today's Message Index:
----------------------
1. 10:12 AM - hydraulic accumulator (Scott Dickey)
2. 12:30 PM - Re: hydraulic accumulator (Tom Fisher)
3. 12:58 PM - Re: hydraulic accumulator (Phil Stubbs)
Message 1
| INDEX | Back to Main INDEX |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | hydraulic accumulator |
--> Commander-List message posted by: "Scott Dickey" <jdickey@radictech.com>
Hi Everyone,
This is just a follow up on my efforts to get my accumulator charged and
working properly. Now you are all probably thinking, What a loser. This guy
doesnt even know how to service his hydraulic accumulator. So for the one
other Commander owner out there who doesnt know how to do this, here are
the tricks I learned over the last week.
1. Connect 600 psi nitrogen to the accumulator fitting and make sure the
fitting is open by turning the locknut counterclockwise at least 2 turns.
Leave the nitrogen source ON and the regulator set for 600 psi +25 / -0 psi.
2. With all power OFF (engine driven and aux pumps), move the flap handle
from the neutral position up or down VERY slowly until you hear the pressure
bleed down to zero (you can see this happen on the gauge and you can hear it
through the flap valve). It turns out the flap valve has a bleed port which
bleeds pressure just before going to the flap UP or flap DOWN position. If
you move the handle slowly, you will hear pressure relieve and see the gauge
go to zero 1/4" or so before getting to the flap UP or DOWN position. Now
the piston in the accumulator is at the end of its stroke with 600 psi
nitrogen on one side and 0 psi hydraulic fluid on the other.
3. Check your accumulator for internal leaks. Now that you have 600 psi on
the accumulator, you can see and hear if the piston o ring is leaking. If
you hear anything then open the hydraulic fluid reservoir to see if there is
any foam or bubbles. If there is nothing, proceed to step 4. If you see
bubbles and the thing is hissing away, take a deep breath and cancel any
upcoming trips. The good news is that you can get the whole accumulator
overhauled by Higher Planes for just $1800. And since those accumulators
just jump in and out practically by themselves, its a real bargain! But if
you need it done, they have a FAA approved overhaul for that component
(along with other commander stuff like power brake valves).
http://www.higherplanes.com/
4. With the nitrogen still ON, tighten the lock nut on the fitting and
remove the nitrogen fill hose (don't forget to turn off the Nitrogen before
removing the fitting - 600 psi is A LOT of pressure).
I believe this is the first time I've flown the airplane with the
accumulator serviced properly. The hydraulic pressure gauge now barely
moves, even when actuating the flaps, brakes, etc. It used to snap back and
forth during flight and especially when using the system. When serviced
properly, the accumulator does and excellent job of dampening the pressure
in the system, to the point where there is almost no pressure fluctuation at
all. If your gauge moves much at all or if you see any rapid movements,
chances are you have flat or low accumulator pressure.
The other trick to doing this properly is finding a nitrogen source that can
go up to 600 psi. Almost everyone has a N2 bottle with the welder style
regulator but most of those cannot regulate to 600 psi downstream pressure.
I decided to look for the components to buy and I really had to search for a
regulator that could regulate to 600 psi. Most regulators that I saw have
maximum of 350 - 450 psi regulating ranges. They maybe go a little higher
but you're lucky if your mechanic has the proper rig. If you are planning to
build your own rig, plan on spending about $500. Here are sources for
everything you will need:
1) 110 cu foot or larger N2 bottle - any local welding shop. About $200
buys the bottle and refills are cheap.
2) 0 - 1500 psi high pressure regulator. Available from
www.weldingsupply.com. Item # 3200300, about $230.
3) High pressure hose and N2 ground service fitting. Available from Hoses
Unlimited (510-483-8520). They will make up a hose of any length and sell
you the fill fitting as well. The regulator terminates in 1/4 NPT female so
you want a hose with 1/4 NPT male on one end.
So that's it. Anyone who is ever in the LVK area stop by for a free N2 fill.
* Credit goes to the service manager at DownTown Airpark for telling me
about that bleed port.
Message 2
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: hydraulic accumulator |
--> Commander-List message posted by: "Tom Fisher" <tfisher@commandergroup.bc.ca>
This article is a keeper, thanks Scott.
Tom F.
----- Original Message -----
From: "Scott Dickey" <jdickey@radictech.com>
Subject: Commander-List: hydraulic accumulator
> --> Commander-List message posted by: "Scott Dickey"
<jdickey@radictech.com>
>
> Hi Everyone,
>
> This is just a follow up on my efforts to get my accumulator charged and
> working properly. Now you are all probably thinking, What a loser. This
guy
> doesnt even know how to service his hydraulic accumulator. So for the one
> other Commander owner out there who doesnt know how to do this, here are
> the tricks I learned over the last week.
>
> 1. Connect 600 psi nitrogen to the accumulator fitting and make sure the
> fitting is open by turning the locknut counterclockwise at least 2 turns.
> Leave the nitrogen source ON and the regulator set for 600 psi +25 / -0
psi.
>
> 2. With all power OFF (engine driven and aux pumps), move the flap handle
> from the neutral position up or down VERY slowly until you hear the
pressure
> bleed down to zero (you can see this happen on the gauge and you can hear
it
> through the flap valve). It turns out the flap valve has a bleed port
which
> bleeds pressure just before going to the flap UP or flap DOWN position. If
> you move the handle slowly, you will hear pressure relieve and see the
gauge
> go to zero 1/4" or so before getting to the flap UP or DOWN position. Now
> the piston in the accumulator is at the end of its stroke with 600 psi
> nitrogen on one side and 0 psi hydraulic fluid on the other.
>
> 3. Check your accumulator for internal leaks. Now that you have 600 psi
on
> the accumulator, you can see and hear if the piston o ring is leaking. If
> you hear anything then open the hydraulic fluid reservoir to see if there
is
> any foam or bubbles. If there is nothing, proceed to step 4. If you see
> bubbles and the thing is hissing away, take a deep breath and cancel any
> upcoming trips. The good news is that you can get the whole accumulator
> overhauled by Higher Planes for just $1800. And since those accumulators
> just jump in and out practically by themselves, its a real bargain! But if
> you need it done, they have a FAA approved overhaul for that component
> (along with other commander stuff like power brake valves).
> http://www.higherplanes.com/
>
> 4. With the nitrogen still ON, tighten the lock nut on the fitting and
> remove the nitrogen fill hose (don't forget to turn off the Nitrogen
before
> removing the fitting - 600 psi is A LOT of pressure).
>
> I believe this is the first time I've flown the airplane with the
> accumulator serviced properly. The hydraulic pressure gauge now barely
> moves, even when actuating the flaps, brakes, etc. It used to snap back
and
> forth during flight and especially when using the system. When serviced
> properly, the accumulator does and excellent job of dampening the pressure
> in the system, to the point where there is almost no pressure fluctuation
at
> all. If your gauge moves much at all or if you see any rapid movements,
> chances are you have flat or low accumulator pressure.
>
> The other trick to doing this properly is finding a nitrogen source that
can
> go up to 600 psi. Almost everyone has a N2 bottle with the welder style
> regulator but most of those cannot regulate to 600 psi downstream
pressure.
> I decided to look for the components to buy and I really had to search for
a
> regulator that could regulate to 600 psi. Most regulators that I saw have
> maximum of 350 - 450 psi regulating ranges. They maybe go a little higher
> but you're lucky if your mechanic has the proper rig. If you are planning
to
> build your own rig, plan on spending about $500. Here are sources for
> everything you will need:
>
> 1) 110 cu foot or larger N2 bottle - any local welding shop. About $200
> buys the bottle and refills are cheap.
> 2) 0 - 1500 psi high pressure regulator. Available from
> www.weldingsupply.com. Item # 3200300, about $230.
> 3) High pressure hose and N2 ground service fitting. Available from Hoses
> Unlimited (510-483-8520). They will make up a hose of any length and sell
> you the fill fitting as well. The regulator terminates in 1/4 NPT female
so
> you want a hose with 1/4 NPT male on one end.
>
> So that's it. Anyone who is ever in the LVK area stop by for a free N2
fill.
>
>
> * Credit goes to the service manager at DownTown Airpark for telling me
> about that bleed port.
>
>
Message 3
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | hydraulic accumulator |
--> Commander-List message posted by: "Phil Stubbs" <br549phil@mindspring.com>
Thanks for the excellent article. You included some important details I
was not aware of.
Phil
> [Original Message]
> From: Scott Dickey <jdickey@radictech.com>
> To: <commander-list@matronics.com>
> Date: 5/24/2004 1:09:29 PM
> Subject: Commander-List: hydraulic accumulator
>
> --> Commander-List message posted by: "Scott Dickey"
<jdickey@radictech.com>
>
> Hi Everyone,
>
> This is just a follow up on my efforts to get my accumulator charged and
> working properly. Now you are all probably thinking, What a loser. This
guy
> doesnt even know how to service his hydraulic accumulator. So for the one
> other Commander owner out there who doesnt know how to do this, here are
> the tricks I learned over the last week.
>
> 1. Connect 600 psi nitrogen to the accumulator fitting and make sure the
> fitting is open by turning the locknut counterclockwise at least 2 turns.
> Leave the nitrogen source ON and the regulator set for 600 psi +25 / -0
psi.
>
> 2. With all power OFF (engine driven and aux pumps), move the flap handle
> from the neutral position up or down VERY slowly until you hear the
pressure
> bleed down to zero (you can see this happen on the gauge and you can hear
it
> through the flap valve). It turns out the flap valve has a bleed port
which
> bleeds pressure just before going to the flap UP or flap DOWN position. If
> you move the handle slowly, you will hear pressure relieve and see the
gauge
> go to zero 1/4" or so before getting to the flap UP or DOWN position. Now
> the piston in the accumulator is at the end of its stroke with 600 psi
> nitrogen on one side and 0 psi hydraulic fluid on the other.
>
> 3. Check your accumulator for internal leaks. Now that you have 600 psi
on
> the accumulator, you can see and hear if the piston o ring is leaking. If
> you hear anything then open the hydraulic fluid reservoir to see if there
is
> any foam or bubbles. If there is nothing, proceed to step 4. If you see
> bubbles and the thing is hissing away, take a deep breath and cancel any
> upcoming trips. The good news is that you can get the whole accumulator
> overhauled by Higher Planes for just $1800. And since those accumulators
> just jump in and out practically by themselves, its a real bargain! But if
> you need it done, they have a FAA approved overhaul for that component
> (along with other commander stuff like power brake valves).
> http://www.higherplanes.com/
>
> 4. With the nitrogen still ON, tighten the lock nut on the fitting and
> remove the nitrogen fill hose (don't forget to turn off the Nitrogen
before
> removing the fitting - 600 psi is A LOT of pressure).
>
> I believe this is the first time I've flown the airplane with the
> accumulator serviced properly. The hydraulic pressure gauge now barely
> moves, even when actuating the flaps, brakes, etc. It used to snap back
and
> forth during flight and especially when using the system. When serviced
> properly, the accumulator does and excellent job of dampening the pressure
> in the system, to the point where there is almost no pressure fluctuation
at
> all. If your gauge moves much at all or if you see any rapid movements,
> chances are you have flat or low accumulator pressure.
>
> The other trick to doing this properly is finding a nitrogen source that
can
> go up to 600 psi. Almost everyone has a N2 bottle with the welder style
> regulator but most of those cannot regulate to 600 psi downstream
pressure.
> I decided to look for the components to buy and I really had to search
for a
> regulator that could regulate to 600 psi. Most regulators that I saw have
> maximum of 350 - 450 psi regulating ranges. They maybe go a little higher
> but you're lucky if your mechanic has the proper rig. If you are planning
to
> build your own rig, plan on spending about $500. Here are sources for
> everything you will need:
>
> 1) 110 cu foot or larger N2 bottle - any local welding shop. About $200
> buys the bottle and refills are cheap.
> 2) 0 - 1500 psi high pressure regulator. Available from
> www.weldingsupply.com. Item # 3200300, about $230.
> 3) High pressure hose and N2 ground service fitting. Available from Hoses
> Unlimited (510-483-8520). They will make up a hose of any length and sell
> you the fill fitting as well. The regulator terminates in 1/4 NPT female
so
> you want a hose with 1/4 NPT male on one end.
>
> So that's it. Anyone who is ever in the LVK area stop by for a free N2
fill.
>
>
> * Credit goes to the service manager at DownTown Airpark for telling me
> about that bleed port.
>
>
Other Matronics Email List Services
These Email List Services are sponsored solely by Matronics and through the generous Contributions of its members.
-- Please support this service by making your Contribution today! --
|