Hydraulic fluid flush on a Case 480ck

[Abseim]

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!

 

[Tinkerer]

I have done it and had excellent results. It is tedious and requires a lot of new oil.
Don't contaminate the system with kerosene or diesel fuel. Use new hydraulic oil.
Don't force dirty oil back into the tank.
Below are links to a couple of threads on how to do it.
The swing cylinders are kinda unsafe to do.

https://www.heavyequipmentforums.com/showthread.php?t=14595

https://www.heavyequipmentforums.com/showthread.php?t=19687

 

[Abseim]

Thanks! Unfortunately those links aren't working for me on my phone or desktop...

What is dangerous about the swing cylinders vs others?

Is there any specific oil I can use besides the Case TCH? In one part of the service manual it says I can use 10w motor oil above 32deg and 5w below 32

 

[Delmer]

The transmission needs TCH or hytran or equivelant. The hydraulics need a hydraulic oil, which could be lot of different oils, could be TCH or hytran, but not required.

#5 is the best way to get the old oil out. I don't think it's needed though. The water in that oil is the issue. You can get the water out by a number of methods, heating the oil and bubbling air through it is what has worked for me. Vacuum and heating, or boiling works also. Set it up so you can do it easily, because you will have to repeat many times, as you've shown by how little you change just draining it. Do that until you get no more noticeable moisture, and change the filter. You'll add enough new oil when you pop a hose...

 

[Abseim]

The transmission needs TCH or hytran or equivelant. The hydraulics need a hydraulic oil, which could be lot of different oils, could be TCH or hytran, but not required.

#5 is the best way to get the old oil out. I don't think it's needed though. The water in that oil is the issue. You can get the water out by a number of methods, heating the oil and bubbling air through it is what has worked for me. Vacuum and heating, or boiling works also. Set it up so you can do it easily, because you will have to repeat many times, as you've shown by how little you change just draining it. Do that until you get no more noticeable moisture, and change the filter. You'll add enough new oil when you pop a hose...

Thanks, I have a fully mechanical transmission with a dry clutch, and I'm pretty the gearcase takes regular 90 weight gear oil... Any issues going with 140weight?

Also, those weren't 5 different options, they were steps in order, haha, not sure if you misread.

I definitely want to do a full drain, I have no idea how old this oil is or whats in it, and I'd like to have a fresh start. This tractor is 55 years old and has plenty of battle scars, but it's still a solid machine and I think I can get many more years out of it doing light duty work around my property.

 

[Abseim]

I have done it and had excellent results. It is tedious and requires a lot of new oil.
Don't contaminate the system with kerosene or diesel fuel. Use new hydraulic oil.
Don't force dirty oil back into the tank.
Below are links to a couple of threads on how to do it.
The swing cylinders are kinda unsafe to do.

https://www.heavyequipmentforums.com/showthread.php?t=14595

https://www.heavyequipmentforums.com/showthread.php?t=19687

Thanks Tinkerer! Your links aren't working but I just punched in 14595 in the search bar and I found the old thread, here's the link that works: https://www.heavyequipmentforums.com/threads/quick-fluid-change-ques.14595/

I repacked the 4 worst leaking cylinders last weekend and will do a few more this next weekend. The main seal in all four glands was totally mush, it would just crumble out in chunks that I could crush between my fingers... I have no idea how I was even able to use the hydraulics at all with the seals that bad.

I assume the rest of the cylinders will be similar, now that I've put a few hours on the machine ripping out stumps I can see every other gland starting to leak as well.

There was also a significant about of grit and junk that came out of the bottom of the cylinders that I assume got trapped. Uggh...
But the good news is that I finished the dipper cylinder late Saturday night and stuck the hoe up in the air and measured the bucket height off the ground, and the next morning it had only sunk about 2 inches! Before I could literally watch the bucket drop after I let off the controls...

I still haven't drained the fluid yet, I'm hoping to get to that this weekend as well. It still looks like melted mayonnaise, even though I've added 10 gallons now to the 20 gallon system.

My question now is, what do I put back in after the flush?

I'm leaning towards using Traveller ISO 46 hydraulic fluid. This machine has a standalone hydraulic system and has a totally mechanical transmission with a dry clutch, so i figure this would be a good choice? Anyone have a better suggestion? This is an old clapped out hoe that lives in the woods and I'm not looking to invest a fortune or drive to the case dealer over an hour away...

 

[Abseim]

Swing cylinders with new seals



Draining some salad dressing... And these swing cylinder bushings are extremely worn, so much slop on the little joints mounted mid cylinder



Using a comealong to pull swing cylinders.

 

[Tinkerer]

The Travelers oil would be OK. ISO 32 would be my choice it you plan on doing any work in really cold weather.
80/90 would be a better choice for gear oil.
Changing the bushings may save the cylinders from getting destroyed if they get loose in the bores.
The trunnions they pivot on can be welded up and cut to OEM specs on a lathe.

 

[Abseim]

The Travelers oil would be OK. ISO 32 would be my choice it you plan on doing any work in really cold weather.
80/90 would be a better choice for gear oil

Yes, definitely, I would only use the iso 46 for the hydraulic system, and would use 80/90 for the final drive.

One thing I'm still trying to figure is if my mechanical shuttle needs its own fluid, not gear oil. And I'm also stumped about this white plastic thing with the clip in the pic below. I've studied every page of the parts manual and it isn't shown anywhere that I can find. This is the four speed gearbox with the cover removed.

 

[edgephoto]

You have water in the oil. Make sure to flush things good.

 

[Abseim]

You have water in the oil. Make sure to flush things good.

Yes, there is water in every fluid in this machine! Any tips to flush it out good? The service manual says to cut it with 50% kerosene.

The gloop that came out when I drained the engine oil was the worst! But I've changed the oil and filter twice after running it for a few hours and it seems to have cleared that up. I've also flushed out the power steering.

Next is the hydraulic system and the gearcase, and possibly the shuttle if that has a separate oil reservoir.

 

[edgephoto]

Was your machine submerged at some point. Wonder how all that water got in there?

 

[Tinkerer]

The shift lever rubber boot is usually one way for water to get in a gear box.

What is dangerous about the swing cylinders vs others?

The way I do it requires the backhoe to be off of the ground so that it can be swung from one side to the other with all the hoses removed from the cylinders. That will force ALL of the oil out of them.
But it is dangerous because you could get injured from a boom that can swing freely.

 

[Abseim]

Was your machine submerged at some point. Wonder how all that water got in there?

I don't know anything about it's history, but it has ancient dealer stickers from a town nearby... a 55 year old machine that has clearly done some work, several of the hoe teath are worn down to rings... probably been someone's beater machine for decades, and stored outside in the Catskill mountains with 60" average rainfall and 4 months of freezing nights, I think it's mostly condensation and rain through the taped up breathers. If the machine was only ever run for short periods and never spent much time running at operating temp over the past 15-20 years and no one changed the fluids or just topped them off with whatever was available, it makes sense that the fluids all have picked up water.

Here it is this morning moving a pine stump, I worked the machine for about an hour to warm up the fluid and drained the tanks and the main 1" loop from the pump to the return filter. Tomorrow I will go cylinder by cylinder like tinkerer talks about in his other threads and drain each circuit.

 

[rumblecloud]

I admire your resolve in resurrecting it. Even after all it's been through, it looks to have some balls.
Hats off.

 

[Abseim]

I admire your resolve in resurrecting it. Even after all it's been through, it looks to have some balls.
Hats off.

Thanks! I just finished flushing out the hydraulics following tinkers advice, I'd say I was able to flush out about 90%. I didn't think through the positions of the boom and stabilizers good enough and I wasn't able to completely empty those cylinders.

Also, the tank drain wasn't at the bottom of the reservoir, it was about an inch or so up, and just a 3/4" hole and I stuck my finger in after draining and felt a whole pile of crud and metal chips... I worked up the pile with a frayed up scrap end of battery cable while my son poured kerosene in the top breather ports... Did this several times on both sides til it started coming out somewhat clear... Went through 2 gallons of kerosene. I took a little ring magnet on a string and pulled out all sorts of metal chunks. There were still chunks inside that I suppose weren't magnetic, I think I could feel pieces of paper gasket that I could feel stuck to wall of tank.

I wish I knew where the pickup for the pump is inside the loader frame. I have all the parts and service manuals for this machine but nothing with a cutaway of the loader frame reservoir.

It's a 19 gallon system, I bought 25gallons (5x 5 gallon pails) of iso-46 fluid and it took about 3 hours, I still have a half pail left. I couldn't get some of the connections to come loose so I had to break some lines in the middle instead of close to the cylinders, meaning there was some old fluid left.


However, the water pump/fan shaft was getting wobbly, its been on the list to replace, but while I was doing the flush it got worse and worse and eventually the fan blade started hitting the radiator and now the radiator is leaking...

 

[Abseim]

 

[Abseim]

Uggggh, the coolant system is only shown in the parts catalog... Nothing else in the service manual... just instructions for the water pump, nothing about the radiator...

 

[edgephoto]

Now that you flushed it maybe something like this to get the rest of the water out?

Water absorber

 

[Abseim]

Now that you flushed it maybe something like this to get the rest of the water out?

Water absorber

That looks pretty neat! And a great price too! Unfortunately I only have a 1" hole at the top of the loader frame and the main loader bushing sits right inside so close that I have to put on a 1" pipe nipple to even get a funnel to stay in place. I don't think I'd be able to fit that inside unfortunately.

The OCD engineer part of me wants to rig up a whole filter loop plumbed off the tank drains with water absorbers and micron filters, but then I remind myself that this is an old clapped out basket case and there are a dozen other things to fix first, and really I just need to get a half acre of stumps ripped out and the ground leveled for my new shop in the woods, so I can get back to carpentry, haha

I called Dale at e-backhoeparts.com and have a new water pump, radiator hoses and a few random gaskets and seals coming. I've also watched a dozen YouTube videos on radiator repair so I should be able to get this giant hunk of iron moving again next weekend.




I also think I need to replace the front crankshaft seal while I'm at it. Anyone know if I can do this without pulling the timing cover?



What a mess, haha, I had no idea what I was getting into when I got this thing, I only ever worked on single cylinder mower and chainsaw engines before, I thought I was gonna just change the oil, put in some fresh gas and start digging but now I'm beginning to understand why excavation contractors charge what they do!