580C Hydraulic Tank Leak

[jbender]

Found a puddle this morning, and realized that the hydraulic tank is rotted in one spot near the floor. I'm hopeful now that I got the area cleared out and things cleaned up that this can be welded - so I don't fee quite as sick now

Let me know what you guys think - is this weldable with a cover plate?







Does this tank need to be empty before welding this? Unfortunately a (quite strong) impact was not able to get the drain plug off. It showed signs of stripping so I stopped trying. I ground down a 3/4" to 1/2" drive adapter to have better engagement (no end chamfer) and can try that. Would it be safe to put a oxy-acetylene on the drain plug to loosen that up?

In case those who live in nicer climates are unaware - this is rotted most likely due to salt on the roads and this machine having driven many miles during it's career.

 

[cosmaar1]

Found a puddle this morning, and realized that the hydraulic tank is rotted in one spot near the floor. I'm hopeful now that I got the area cleared out and things cleaned up that this can be welded - so I don't fee quite as sick now

Let me know what you guys think - is this weldable with a cover plate?

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Does this tank need to be empty before welding this? Unfortunately a (quite strong) impact was not able to get the drain plug off. It showed signs of stripping so I stopped trying. I ground down a 3/4" to 1/2" drive adapter to have better engagement (no end chamfer) and can try that. Would it be safe to put a oxy-acetylene on the drain plug to loosen that up?

In case those who live in nicer climates are unaware - this is rotted most likely due to salt on the roads and this machine having driven many miles during it's career.

Do not attempt to weld that with oil in the tank. Hydraulic oil is very flammable.

Drain the tank, clean the crap out of it with soap and water, cut the section out and fix it, and clean the crap out of it again.

I just did this on my 555e.

 

[Billrog]

I've welded up a few cracks in hydraulic tanks after draining them and grinding out the crack but I'm not to sure how you'd put a patch on that rusted out area. Where exactly is it leaking.

 

[jbender]

Looks like I'll have to figure out how to get that drain plug loose and clean out the tank. How many gallons is in just the tank?

I was planning on cutting off the bracket there to give myself a flat surface to work with. A rectangular plate the width of the column could be welded around the edges to good metal to make a seal. That's the hope, at least?? I'm not a welder and looking for someone that might attempt it.

 

[NH575E]

If you can't drain it pump it out. I use a $15 diesel pump to pump mine before I remove the drain plug. Saves on a lot of mess. You are going to want to remove it and turn it upside down. My old radiator shop said they flush all gas or oil tanks out with tide laundry detergent before they put heat to them.

I just tried welding a hydraulic hard line and it didn't work well. I brazed it and built a layer of brass over the whole area and so far that is holding. You might get that clean enough with a wire brush on a grinder to braze it?

 

[Welder Dave]

Flush the reservoir out. Heating the drain plug should be OK. What I would probably do is make a patch plate that bends around the corner and extends at least 1/2" past the rusted sections. You could weld a new mount on the patch plate. Make it out of at least 3/16" steel, 1/4" would be better. I wouldn't try to cut the rusted section out and weld in a new section. You don't want grindings or welding slag inside the reservoir. I'd imagine the leak is pretty small so wouldn't affect anything with the patch over it. Would probably still leak in between the existing tank and the patch but that wouldn't matter as long as the patch was properly welded.

 

[jbender]

Hi Dave. Thanks, I'll put some heat on the plug to see if that will come out. I was going to clean things up on the surface and get down to shiny metal in the hopes that a flat piece could do it, but was thinking along the lines you are if it needs it.

 

[Tinkerer]

X2 on Dave's suggestion.
A shop vac and a suck bucket with a long hose will remove all but few drops of oil from the tank.

 

[HarleyHappy]

I may be in the wrong here but have welded many hydraulic tanks as long as the fluid was over the crack or rust area and before you flame me I am aware of how flammable hydraulic fluid is always have best luck with filling hole or crack with 6011 as even the flux will seal and then over it with 7018.
As small as that area is 4”x5” I would just mig passes from the bottom up and then fill in as needed.

 

[Welder Dave]

If there's oil in the tank, the heat from welding would draw the oil out. No different than trying to weld or braze a hyd. line. Also some of the oil would get burnt and you don't want any welding slag to get in the tank. 6010/6011 would most definitely leave slag on the underside of the weld, especially if a full penetration weld was done or you burnt through. With bad corrosion like that it can be difficult to know how thick the steel is. The area in question is pretty big to be putting a pad of weld beads on. Trying to grind it nice and smooth without being wavy would be difficult too. I'd wire brush it to remove all the paint and rust and just weld a patch plate over it. Very little chance of oil contaminating the weld and would be nice and smooth. Just have to make sure you put a sound weld around the patch. If done with 7018 could pretty much visually inspect the weld for any flaws or bad tie ins, etc.

 

[jbender]

We're going to go after this in the morning. I used Tinkerer's suggestion (thank you!) and made up a suck bucket and took out a few gallons to get the level below the leak (the plug decided it is NOT going to come out). We're going to make up a plate and weld all the way around on (mostly) solid 1/4" thick metal - no cutting of the tank - just leave the pinhole where it is. This is the frame of the machine so there is no way to "remove" it, FYI. There seems to be a shelf or baffling internally, so I don't think the oil is even close to that spot, but it's tough to tell.

I've got a tank of CO2 and some tubing that I'll use to purge the volume of air / oxygen and keep if flowing as we go. If anyone has any dire predictions - let me know!

 

[stinky64]

Something to ponder, there is a T of sorts at the front of the pump for the supply side that is fed from both sides of the loader frame that I think will allow the tanks to self level and perhaps fill the other side back up so ya may want to recheck the side you will be welding for a higher level before you start welding.Maybe you can get lucky with the plug on the opposite side.

 

[jbender]

I understand a lot of that - but maybe I'm missing something. Do you think they might have ended up at different fill heights? That maybe it could run back to the tank I'm welding on somehow? I would check the level on the other side, but not sure I know of any way to do that.

 

[stinky64]

I'm pretty sure they will self level via the T in the supply feed that supplys the hydraulic pump so oil will go from left tank to right tank or vise versa. If you can drain the oil out of the opposite tank you are welding the level should go down more than enough to weld and will be beneficial to get any moisture out of that side of the system as well.

 

[Welder Dave]

You want to get as much oil out as possible and leave the fill cap off when welding. Wouldn't be a bad idea to put some non flammable solvent in and then extract it. It should thin out the oil and help remove more of it. How hot did you heat the drain plug? Seems it should come loose with enough leverage after being warmed up. If the tanks are higher than the pump, remove the suction side of the pump and drain the hyd. oil that way. You could plug the intake hose and even put some water in the tank to make welding safer. I don't think hyd. oil would pose a real big problem welding your patch plate on though. Similar to diesel fuel tanks that are welded regularly. Make sure every port on the reservoir is open so it can vent.

 

[jbender]

I think I might have it where I want it... It's a bit confusing because there is some kind of baffling in the frame. The hydraulic fluid is some distance from the area we will be welding. You can reference my detailed drawing below. It's the best I can tell from poking around in there from the fill hole - I can't see in much. The fluid is only down in a recess to the left at this point.

 

[Welder Dave]

If you could put some epoxy or emergency gas tank sealer on the pin hole it would help to basically eliminate the chance of drawing oil into the weld.

 

[jbender]

Got it done!



Ran a 10 pound tank of CO2 through it while we did it. Next time I would turn the flow down a bit since I ran out just before we were done.

In case it matters to anyone, the inside of this is different that what I thought, and I ended up getting another ~5 gallons out of this after prodding around with my suck hose. There was access to lower in the frame to the right of the fill hole.

 

[Tinkerer]

Awesome repair !
Kudos to Willie59 for inventing the suck bucket.

 

[Steve Favia]

Wow,that looks great hope that care of the leak.