Audi bomb recharge

[Joel Skousen <jskousen@enol.com>]

Dan wrote:
A warning...
I mentioned this repair to my mechanic, and he suspects
that in most cases, a pinhole in the bladder will allow
the pressure to leak out again over time.
He also suspects that the nitrogen leaking out and seeping
into the pentosin is/was a cause for some of the leaks 
he's seen.  
It's worth the experiment, but let's see how Joel's bomb
holds up before you all start drilling :)

The mech may be right, but in my opinion, no one can know very much
about these accumulators until you dig into them--and I don't think many
mechs have actually done any of that.  We don't need a lot of people
sitting around waiting to see how my bomb is doing--we need lots of
others trying it--what have we got to lose?  Now I am not suggesting
that any person drill a working bomb--why take the risk.  Wait until it
loses its pressure, and then add the valve and try a recharge.   Even if
it does leak down after a year or two (which I doubt), a cheap recharge
every other year is still a lot less money than one new bomb.  Besides,
once you have a dead bomb--its never coming back to life on its own, so
go ahead and put a valve in it and see if it can be revived.  

If you don't get any oil out of the casing after drilling the hole,
chances are pretty good the bladder is intact.   I did drill a bomb from
the boneyard yesterday that (as I found out later) had a bladder that
had come completely disconnected from its attachment point inside the
casing.  Naturally I got oil out my hole when I drilled it.  I cut the
case open just to see if the oil was from my drilling a hole in the
bladder or something else.  I was glad it was some other cause, because
I had been very careful in drilling.  

I also wanted to separate the valve pack end from the bomb casing just
to see if the valve/hydraulic attachment core could be attached to a new
accumulator.  HYDAC brand accumulators makes a unit ($99) identical in
shape to our Audi bomb, with a schraeder valve built in on top--right
where our mounting stub is.  But it has a 1/2" size 8 SAE threaded
attachment point at the base (meant to screw into another hydraulic
unit), where our audi valve pack/hyd attachment point is normally
attached.  When I cut off the valve pack on my bomb, I found that the
spring loaded ball valve that keeps the Pentosin inside the bladder is
sitting exactly in between this welded joint and the bomb portion.  When
I cut the weld, the spring and retainer popped out--there was no
separate housing to hold this to the valve pack side--thus ruling out
being able to find some suitable attachment to the HYDAC unir.  

I'll keep experimenting with old bombs and hope others do to.  

Best, Joel
-----------------------------------------------------------
Joel M. Skousen         <mailto:jskousen@enol.com> 
Joel Skousen Designs    WebSite: <http://xsw.com/securehome>
290 W. 580 S.           Telephone:  (801) 224-4746        
Orem, Ut 84058