Suggestions for repairing hydraulic cylinder on shop press.

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I have a 30'ish year old Bristol Tools 20-ton shop press.  After too many years in storage I pulled it out resealed it, added a little paint and got it ready to work.  To test my new seals and reassembly I applied about 1800 psi to the system by pressing an a 1" plate.This is when I found the tiny oil leak on the rear of the cylinder.  The new paint hides the exact location of the leak, but it appears that the oil is coming from the area between the fillet weld and the plate that the cylinder is welded to.  The leak is very small and only appears under high pressure.My question for everyone is, how would you repair it?  Is welding the best option?  Are there other options?  I can see some difficulties with welding with oil contamination.  I my welding resources are a Hobart Handler 210MVP mig rig and a Hobart TigWave 250 tig/stick machine.  My welding skills are in the beginner to moderate range.I am looking for ideas if anyone is willing to make suggestions or point out possible downfalls.  I am a machinist by trade, so working with metal and disassembling/assembling the cylinder is no problem.Here are a few photos.  This one is of the cylinder on the press.And this is a close up of the weld and the small leak forming.  I highlighted the area of the leak because clean hyd. fluid doesn't show up well on new paint.Thank you in advance for your help.R.J. Attached Images
Reply:I vote to -at most- wrap an "oil pig" absorbing wick around it and forget it.
Reply:If you decide to repair it.. Remove all the parts you can and wash the oil out. Grind paint off and grind into the area that's leaking a little. Weld, paint, put everything back inside. It doesn't take much to seal a small pinhole like that so don't go too crazy with the grinding.Airco Ac/Dc 300 HeliwelderMillerMatic 200 (stolen)Miller Maxstar 150STLMiller AEAD200LE (welding and generating power) Hobart MIG
Reply:i've built up shafts and worn parts that have been submerged in gear boxes, rear ends etc.    Even, when they look clean, there has been oil impregnated in the steel.   Major contamination when striking an arc.   I've taken a torch, and cooked the oil out, and have watched it smoke and oil bubble out.   Eventually it stops smoking and boiling, then I could weld it w/o oil contamination/porosity.    Most  don't believe me when i tell them that though.   But I'd think your up against the same thing.
Reply:This was a quick and dirty fix on a hydraulic cylinder leak the customer didn't want to spend the money (or time) on getting done right.   The cylinder was fully assembled when I did it.  Ground out the crack a little bit and ran a quick pass with 1/8 7018 over it.   There was still a little hydraulic oil weeping from the crack when I welded over it.   Didn't have any visible porosity in the weld.   As far as I know it held because the cylinder didn't come back to the shop.   I wouldn't recommend this as a general practice but every now and then you luck out.
Reply:Originally Posted by HT2-4956This was a quick and dirty fix on a hydraulic cylinder leak the customer didn't want to spend the money (or time) on getting done right.   The cylinder was fully assembled when I did it.  Ground out the crack a little bit and ran a quick pass with 1/8 7018 over it.   There was still a little hydraulic oil weeping from the crack when I welded over it.   Didn't have any visible porosity in the weld.   As far as I know it held because the cylinder didn't come back to the shop.   I wouldn't recommend this as a general practice but every now and then you luck out.
Reply:Originally Posted by manningIn the past, when we've had someone do a "quick and dirty" cylinder repair it never worked out. Often it was to provide a temporary fix to keep going until a new part arrived. We've never called the shop back to say it failed. Sometimes the cost of a quick repair is cheaper than the next day air freight on the new part.
Reply:Originally Posted by HT2-4956manning,That could very well have been the case with this cylinder.   It might have just kept the customer going on a rush job until he could get a replacement cylinder in.   I know when the machinist came got me and asked me to pull my machine over and make that weld I was highly skeptical of it working out very well.   I remember voicing some concerns but basically ended up getting told to do it because it was what the customer wanted us to try.
Reply:Originally Posted by HT2-4956This was a quick and dirty fix on a hydraulic cylinder leak the customer didn't want to spend the money (or time) on getting done right.   The cylinder was fully assembled when I did it.  Ground out the crack a little bit and ran a quick pass with 1/8 7018 over it.   There was still a little hydraulic oil weeping from the crack when I welded over it.   Didn't have any visible porosity in the weld.   As far as I know it held because the cylinder didn't come back to the shop.   I wouldn't recommend this as a general practice but every now and then you luck out.
Reply:If that was my press, i would remove the springs and run the rod all the way out to keep the piston seals at the opposite end of where you will be working. Remove the cylinder and drain the oil out of it. Grind the weld down where it is leaking and apply a little bit of heat with the torch, just enough to burn the oil out of the crack and then run a small weld over the leak.
Reply:You could try to mechanically seal it with a punch(s). Punch beside to leak not on it. It may seal or reveal a larger problem. A chisel with a small radius ground on the end so it swages instead of cuts.---Meltedmetal