Cylinder Leak

KubotaOne · Mar 23, 2006

One of my FEL lift cylinders is leaking. I've tried teflon tape several times and it appears that the leak is coming from the female fitting that is welded into the cylinder. I can see tiny dots where the paint is removed.

My question is, can I "touch" this up with my MIG welder? Or would the heat be too much for the seals inside the cylinder? My other idea was JBWeld.

Any others had a leak from one of these fittings?

slowrev · Mar 23, 2006

I don't think JB weld would handle the pressure.
Heat on the seals, well it sort of depends is it the connector on the rear or the rod end of the cylinder ? If the rear and the rod is exteneded, heat should not be an issue, but remember the cylinder has combustable oil in it.....
I would recommend checking with a good hydraulic repair shop for repair recommendations.
Ben

Soundguy · Mar 23, 2006

JB weld will have about as much chance as a snowball in he11.. maybee less.

I've imersed smal parts in water up to withing a few inches of where I was welding to help draw heat away from seal... no sure if that would be an option for you. in any case.. you will need to get the oil away from the weld.. it will cause more leaks..

Soundguy

slowrev · Mar 23, 2006

Agreed soundguy. I would think the rod would have to be removed and the oil cleaned well with solvent before welding. Perhaps the leak hole/s drilled out with a small drill to clean them for welding.
Ben

markct · Mar 23, 2006

it all depends where the fitting is, if its at the base end then yea it can be welded by extending the rod, if its at the gland end then ya can either weld it fast and try and keep it cool or dissasemble the cylinder. hydraulic seals can take a good bit of heat realy. often times at work we have to repair damaged hydraulic cylinder fittings or they crack around the base of the tube and endcap. either case the way i usualy do it is to grind it out then clean it with brake cleaner and dry it and heat it some with a propane torch to burn out the last bits of oil then weld it up, stick welding is usualy the method of choice since its alot more tolerant of small amounts of oil

JimR · Mar 23, 2006

I would just weld it up. The piston casing will disperse the heat for you.

Soundguy · Mar 23, 2006

All good advice .. but markct touched on a good point... a few minutes with a small torch will help burn out any oil missed from using brake/carb cleaner.. and they key to less heat is fast welding.. add to that, that arc welders are extremely tolerant of contaminants like paint, rust, grease in the work area.. etc..

Soundguy

KubotaOne · Mar 24, 2006

Thanks for the input guys.

Sounds like this might be more involved than I first thought. The leak is at the base end, not the rod side. Regardless, I think might call my dealer on this one. I'm a rookie welder at best, cheers.

slowrev · Mar 24, 2006

If when welding any slag gets blown inside the cyl then the seals will fail very soon unless cleaned out /forums/images/graemlins/frown.gif One reason for pulling the rod out while welding.
Ben

KubotaOne · Mar 24, 2006

Good point.

I should clarify though, it's not a big crack or large hole, I'm talking pin size hole or two. I thought i could literally just touch it up quick, not run a bead around the whole fitting.

I also thought about swapping cylinders from side to side to at least make sure the leak isn't coming from somewhere else (a fitting or hose) All this talk about welding to find it's not where the leak is in the first place.

</font><font color="blue" class="small">( If when welding any slag gets blown inside the cyl then the seals will fail very soon unless cleaned out /forums/images/graemlins/frown.gif One reason for pulling the rod out while welding.
Ben

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