Wood splitter issue

[Dougie]

I dropped a small O ring into the (empty) hydraulic fluid reservoir on my new wood splitter as I was putting it together.  It is extremely difficult to remove.
If I don't get it out would it pose a risky to the hydraulic system, potentially by getting lodged somewhere in the system and restricting flow?
If yes, any ideas on how to remove it?  I can't just pick up the reservoir (which is part of the wheel system) and shake it.  It's not possible to see the O ring through either of the holes in the reservoir.  I can only think of rigging up something with my vacuum cleaner and creating a "filter" in the line to catch the O ring before it goes into the vacuum cleaner bag (or to let it go into the bag and sort through the dirt and dog hairs in the bag in an attempt to find it).

UPDATE:
I was able to remove the O ring though the hole from the hydraulic line using a tiny flashlight that I maneuvered with two shoelaces attached so I could adjust its azimuth and altitude.  I finally located the ring, dragged it near the hydraulic line hole with a cut-off piece of a coat hanger, and then rebent the coat hanger so that I could catch it and drag it up the side of the reservoir and out the hydraulic line hole.  If I had not been able to see the O ring with the flashlight I might have been SOL.

[sawguy21]

Welcome to the forum!! Have you got a fresh bag for the vacuum? You need to remove it or it will make a real mess in the hydraulics.

[mike_belben]

The pump will chop it up and distribute it everywhere, causing issues in the valve and relief cartridge. 

Use a paper towel roll, with a sock over it, jammed in the vacuum hose and go to town.  Blow air into the tank with a soft copper or brakeline extension tube if you need to jar the oring over to where the vacuum can get it.