I left the tables in the up position overnight and noticed the dirty one dropped more then the clean one. It was dropping about a half inch a night versus approx a 1/16" over night on the clean one. Great I got a leak. I understand the principal behind hydraulics but I have no hands on experience or knowledge of how to repair a hydraulic system. So I started researching and determined its either coming from the cylinder or the check valve in the hydraulic pack. Considering that I could see oil flowing from the vent tube back into the reservoir I was pretty sure I had a bad seal in the cylinder. I took off the vent line and raise the table to its top most position and oil sprayed out...yeah I definitely got a bad seal.
It made sense. Whoever painted the cylinder, forgot to mask the bottom of the rod. So there was a 1" wide line of paint on the underside of the rod and you could see where some had flaked off. My guess is that the paint got in the cylinder and ruined the seal.
So the next step is to get the cylinder repaired. I have no idea how or what I am doing so I called around to try and get a ballpark qoute on what it would cost to repair the cylinder. No one could give me an idea without seeing the cylinder. Youtube and a couple threads here in the GJ to the rescue. Learning something new is always fun...
I took the cylinder off and bought the correct spanner wrench to remove the gland.
Yup, quite a bit of crud in the bottom.
And there is the culprit....hard to see in the pic, but the plastic ring that hugs the o-ring and supports it is bent over and flattened out which would comprise the o-ring.
Definitely some scoring in there too...im guessing from the paint flecks. Most of them I couldn't feel with my nail, but a few I definitely could.
Next step is to figure out new seals and how to clean up the cylinder. Again, I have never done anything like this before so after hours or research and education, I ended up buying a Lisle 15000 Honing tool with the 500 grit stones. While I waited for that I called Martin Fluid Power here in Phoenix. You can bring the seals and or cylinder to them and they will match up the seals. I didn't want to do that though as I would have had to take time off work. So the lady was nice enough to walk me through measuring them over the phone and they shipped the seals to me. $38 and a day later I had two complete sets of seals to do both cylinders. And better seals then I had before. Not bad..
Used some lacquer thinner to take the paint off the rod and installed the new seals. Next up, clean up the cylinder.
There definitely is a learning curve to using that honing tool. The whole time I was worried I was going to screw the cylinder. I started with the 250 grit stone and once I couldn't see the large lines anymore, I switched to the 500 grit to finish it off. It looks much better now and my nail doesn't hang up anywhere.
After that I buttoned it all back up and reinstalled the cylinder. Being that its 18 years old, I figured its probably a good idea to replace the hydraulic hoses while I am at it. Refilled with fresh fluid and I am done. It would have been cheaper for me to pay someone to fix it, especially if you factor in the tools I had to buy and my time. However, I can reuse the tools down the road. As for time, well I consider the learning experience to be invaluable. While I am not expert, I am way more confident with hydraulics now.
I was concerned I maybe honed it to much or what not, but I must have done a decent job. There is no oil coming from the vent and the table dropped less then 1/32" over a 24 hr period. From what I gather, that's really good for tables like these.
This rail had only been used like 4-5 times. This shouldn't be happening already. I suspect its primarily from the heat during the summer time here in Phoenix. The box was leaning against the wall in such a way that the weight of the rail was also pushing on this strip. Granted they don't weigh much, but that also could have contributed to the strip adhesive failing. 
