I have a 480CK I've been bringing back to life, I have the engine running great, starts on the first try every time now, changed engine oil/filter twice, totally drained power steering and changed filter, and I'm going to spend this weekend installing new seals in a few leaking cylinders. I will also flush out transmission as well. All the fluids on this machine look like heavy cream/melted chocolate milkshake. See pic attached of boom cylinder leaking all over:
My question is, is there a systematic way drain the hydraulic fluid before adding any new fluid? The only thing I can find about it in the manuals is to flush with 50/50 kerosene and hydraulic fluid, with a warning not to use 100% kerosene or any solvents, but nothing about the process.
This machine has a ~10 gal hydraulic reservoir, with another ~10 gal in the system. So draining the tank and refilling only gets rid of half the contaminated fluid, and draining again and refilling again only gets rid of 25% contaminated, etc...
When I flushed the power steering I was able to completely drain the system because it can gravity feed down to the cylinders and by disconnecting the cylinders and cycling by hand I was able to empty both sides.
However, the hydraulic system on this machine is much more complicated and won't just drain out with gravity, and I doubt I'll be able to work those cylinders back and forth by hand, other than maybe the stabilizer cylinders... I also understand the dangers of using compressed air in a hydraulic system.
This is my first time working on a hydraulic system, so please let me know if the following is a bad idea, or will damage the machine or is unsafe.
My idea so far:
1. Raise loader and hoe to fully extend each cylinder. Drain hydraulic tanks (left and right loader frame). Carefully drop loader and hoe to push as much fluid back to tank. I assume with an empty tank it will suck air into the other side of cylinders? I'm also wondering if the regen in the valve body will just divert the fluid right back into the other side of cylinder, making this whole step pointless?
2. Pour some kerosene in and try to scrape out any gunk from bottom of tanks with bottle brush through drain holes. (It's impossible to see into tanks as the loader bushing is right inside the breather/fill hole.
3. Disconnect and drain main supply and return hoses from pump, and from loader and backhoe valve bodies. Reconnect hoses, except for final return to reservoir.
4. Fill tank with 10 gal of new fluid, crank tractor til clean fluid comes from return hose. Reconnect return hose, Add more fluid to reservoir. Install new hydraulic filter.
5. Go to each cylinder one at a time and disconnect hoses, with engine idling, work control forward til clean oil comes out, and then work control backward til clean oil comes out. Disconnect piston end from machine and attempt to work back and forth by hand, draining both sides of cylinder. Reconnect hoses. Add new oil to tank as needed.
Is there a better way to do this? Do I need to do this? I've searched google and YouTube, and I can't find much about doing a complete drain of a backhoe hydraulic system.
Thanks for your help!
My question is, is there a systematic way drain the hydraulic fluid before adding any new fluid? The only thing I can find about it in the manuals is to flush with 50/50 kerosene and hydraulic fluid, with a warning not to use 100% kerosene or any solvents, but nothing about the process.
This machine has a ~10 gal hydraulic reservoir, with another ~10 gal in the system. So draining the tank and refilling only gets rid of half the contaminated fluid, and draining again and refilling again only gets rid of 25% contaminated, etc...
When I flushed the power steering I was able to completely drain the system because it can gravity feed down to the cylinders and by disconnecting the cylinders and cycling by hand I was able to empty both sides.
However, the hydraulic system on this machine is much more complicated and won't just drain out with gravity, and I doubt I'll be able to work those cylinders back and forth by hand, other than maybe the stabilizer cylinders... I also understand the dangers of using compressed air in a hydraulic system.
This is my first time working on a hydraulic system, so please let me know if the following is a bad idea, or will damage the machine or is unsafe.
My idea so far:
1. Raise loader and hoe to fully extend each cylinder. Drain hydraulic tanks (left and right loader frame). Carefully drop loader and hoe to push as much fluid back to tank. I assume with an empty tank it will suck air into the other side of cylinders? I'm also wondering if the regen in the valve body will just divert the fluid right back into the other side of cylinder, making this whole step pointless?
2. Pour some kerosene in and try to scrape out any gunk from bottom of tanks with bottle brush through drain holes. (It's impossible to see into tanks as the loader bushing is right inside the breather/fill hole.
3. Disconnect and drain main supply and return hoses from pump, and from loader and backhoe valve bodies. Reconnect hoses, except for final return to reservoir.
4. Fill tank with 10 gal of new fluid, crank tractor til clean fluid comes from return hose. Reconnect return hose, Add more fluid to reservoir. Install new hydraulic filter.
5. Go to each cylinder one at a time and disconnect hoses, with engine idling, work control forward til clean oil comes out, and then work control backward til clean oil comes out. Disconnect piston end from machine and attempt to work back and forth by hand, draining both sides of cylinder. Reconnect hoses. Add new oil to tank as needed.
Is there a better way to do this? Do I need to do this? I've searched google and YouTube, and I can't find much about doing a complete drain of a backhoe hydraulic system.
Thanks for your help!
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