Read a lot of old threads about flushing excavators--not a simple task. I've got the dreaded water in my oil. Read lots of threads about how to remove that too. Time for an oil change. The hard part is purging all the old oil from every nook and cranny. I was thinking, what if I connected an air compressed to the pilot and main pump test ports? Would 120psi of air in the pilot circuit be enough to actuate the main valve body enough to get air through the lines? Then with the machine turned off, tank drained. I could disconnect the lines of the cylinders, motors, and just blow all the lines our with air.
That would only work for the main and return line..........unless you want to you disconnect each secondary line at the main control valve. The secondary line will deadhead at each spool cap so there will be no flow of air. How bad is the water contamination? You may be trying to do too much.
The machine used to leak oil pretty bad. I figured with the amount of 5gal pails I've fed it over the years, the oil would be a lot cleaner--the continual oil flush program. Started the machine at -15F yesterday and the hydraulic oil froze up around the suction strainer. It's pretty milky. I suspect the hardest part will be the tank, main pump and return loop--the basics to get the machine started. Once it's idling with clear fluid in the tank, chasing out everything downstream of the main vale seems straight forward enough. My concern is how many oil changes it'll take before I'm idling clear. I suspect the more old oil I can drain initially, the sooner I'll have a clear tank. I'd like to hear why this is a bad idea: if I connect shop air to the main pump test ports, I'm thinking it would push out a lot of dirty oil through the main gallery, oil cooler?
Give it a try. Let us know how it goes. In the big scheme of things, it only accounts for a small portion of the entire capacity. The reservoir and cylinders contain most of it.
One item to consider is you'll to carefully plan where you want your boom, dipper, and bucket positioned to ensure you get all oil out of your cylinders when you disconnect the hoses. On a side note: Do you have another machine that's time for a change in hydraulic oil? I asked because it might be worthwhile to dump the contaminated oil then flush the machine with the other machine's used hydraulic oil to get more water out. Then fill both machines with new oil.
Might be more beneficial to rent a filter cart and get at it. I did watch a vid of a guy doing an excavator with a AC line and his hydraulic tank and dried the fluid, took awhile though.
I hear you: once I start, I can't make any movements or I push rotten oil back into the tank and I get to start over. Rotate house so the tank drain is in a good spot. Bucket and dipper cylinders retracted and lay down the boom as far as it can go. I was going to roughly follow these instructions: HeavyEquipmentForums Any idea with Nige says step 4: "Loosen (don't remove) a line from the rod end of each boom cylinder." I feel like full disconnect is the way to go? Otherwise it'll blow most of it back to the tank?
Another option to consider instead of compressed air is the @willie59 suckbucket. HeavyEquipmentForums May be easier to crack upstream lines to break vacuum and suck the oil out at the appropriate fitting. Should be able to rig a cheap and easy suck to to any hydraulic fitting you disconnect. And yes, you might be better off disconnecting the fitting instead of breaking it open. All depends on hard the line will be to reconnect and where you suck/blow into it.
Why not just get machine oil hot and let sit. When it cools down all the water in the oil in the hydraulic tank will go to the bottom. Use a straight pipe with a clear hose attached to a 20 liter suck pail, with vaccum and suck out the bottom about 20 liters. Do it with a clean pail and keep the top half of pail as some good oil will come into the pail along with the water. Discard bottom of pail oil. Refill oil and do the same thing 4-5 times and the water should be out. Just to let you know, that water is getting into your system, probably because the oil is being stored in a place at Dealership or your place where the pails are warming and cooling. Every time it cools it sucks back in water. That is my guess how your water is getting into your machine especially in B.C. I lived there before and the up and down in weather every day makes for water in pails. Simon C
Watched a video today of a guy using a vac pump to boil off the water from the oil. Snatch Garage I think? I can't find it now. I had someone put diesel in the hydraulic tank in my Bobcat. Even 5 years and multiple filter and fluid changes it still smells of old diesel.
I don't know how much time and money you want to invest into the job but I think you'd be putting in a lot of effort for minimal return by trying to flush with air. It'd probably leave a lot of residue behind. Depending how bad it is I would probably dump the oil in the reservoir, pig as many of the main lines in the boom and travel circuits as possible and drain the cylinders out. New oil in and cycle it all through a filter cart to catch whatever's left in the valves and manifolds. Before any of that, find and fix the source of water intrusion or you'll be doing it all over again.
You want to empty all the cylinders? Loosen each connections at the cylinder, remove the pilot line from the spool cap. Take a piece of wooden dowel and shift the spool off neutral. This will allow air in to the circuit and allow the oil to return to tank. Travels, you'll have to drain the old fashioned way, just make a mess. Good luck.
Don't forget to drain the cooler. There's probably 5 - 20 gallon in there depending on the size of yer hoe.
I agree. Drain as much as you can and when the oil looks fairly clean run it through a filter cart/ kidney loop to catch the last remnants of water. Tiny amounts of water won't hurt anything and may get caught by the filter.
Just came out a few days ago! I even have a HVAC vac pump. I did save all my old milkshake oil. Probably build one myself out of an old propane tank when I have some down time.
The air wasn't bad, not sure if it was worth the effort. It blew a bunch out of the cooler. It was a day long job. I cycled every cylinder, made a huge mess. I sure hate playing with lines to the boom cylinders while it's up in the air. Not sure where it's coming from. Going to change seals on the tank, although it seems to hold a certain amount of pressure. Suspecting the boom seals. Farmer fix: going to tarp off the boom when it's parked for long periods.
I'm not sure where to get a cart around here. A few threads talked on here talked about the economics of the card, but it seemed like the cost of the filters was similar to the cost of oil. It was long overdue for a change anyway.
A good hydraulic shop might rent a filter cart. A filter cart would help get rid of any water and other contaminates still in the system even after the oil was changed. Just changing the oil won't do what a filter cart will. It's not a bad idea to filter new oil either unless it's certified clean. Most oil isn't.