Flushing backhoe attachment of bad fluid

[DJ54]

I learned about the alcohol about 15 years ago. A fellow on another forum mixed 50/50/ diesel and ATF plus 1 Qt. of rubbing alcohol to flush a transmission on a tractor. I'd bought an old Case backhoe that the transmission oil looked like a yellow milkshake. Put the above mix in and drove it around for 10 minutes and immediately drained it. I had to pull the shift cover off to fix the shifter and could not believe how well it cleaned it up.

Did the same on my little 140 Farmall 4 years ago. PTO bearings were shot due to water in the transmission/differential. Picture below is how well it cleaned it up and removed all the moisture. Mopped out what was left in the bottom with shop rags.

 

[Dunno]

Great pic! Really did clean it up. I’d do the seals on the cylinders that need them along with the flush but have some fruit trees that need to go in the ground this weekend, so I’ll have to wait on that. While we’re at it, I need to free up a frozen rear brake on an old Ford F600. I don’t want to beat on it too much for fear of cracking the hub so I plan to pull the massive thing off the axle and set it in a small tub of homemade pb blaster, which is 1:1 atf and acetone. Thanks again for the great info.

 

[DJ54]

Welcome...

 

[Dunno]

I have hit a snag. I was able to extend the dipper, but cannot get the crowd/boom cylinder to move. I have the hoses disconnected from the control valve in order to let the fluid out, but it is not moving. As you can see in the picture, the weight of the hoe frame mount is in the air whereas you’d think that its weight should be way more than enough to pull the cylinder open. Two thoughts are seized pin on which it is mounted to, or seized cylinder rod. Anyone have any ideas what to try next? Thanks.
PS I spoke to the previous owner and he said it all moved freely for him.

 

[dfkrug]

I have hit a snag. I was able to extend the dipper, but cannot get the crowd/boom cylinder to move. I have the hoses disconnected from the control valve in order to let the fluid out, but it is not moving.

Since you have removed hoses at the valve, try some air. You can just use your airgun with 125psi pressure from your compressor. Movement using air can be sudden, so be careful.

I have used air to clear fluid before, but I prefer to remove as much oil as possible from the cylinders by externally articulating each cylinder, using another machine (tractor, forklift, or hoist). You have to hold the appropriate valve open, plus disconnect the valve return hose and place in a bucket.

 

[Dunno]

Hi DK,
I took you advice and did this earlier. I was able to extend the dipper by lifting and actuating the lever, and it worked. Tried same procedure on boom, but no joy. Will try the air on the line tomorrow. I also found out that half of the cylinders leak. I don’t mind a drip or two, but this thing leaks pretty good, so time to reseal them while I’m at it. I’ll be digging the tree holes the old fashioned way, but hey, good exercise. Thanks for your help.

 

[Dunno]

We’ll, I tried air pressure to the disconnected lines and still no opening of the rod. The rod did move ever so slightly with air to both lines one at a time due to the play between rod eye and lower pin, so I don’t think the rod is seized in the bore. Leads me to think there is either a jam or seizure of the bottom boom pin. PO said it cycled for him, so I’ll take his word on it for now. Anyone have an idea of what could be holding the frame up in the air? I’m hoping I’ve over looked something. It is a Bradco 11HD rebranded by Gehl, so a pretty common piece of gear. Thanks,

 

[LouNY]

I'm sure that you have checked but does it have a "transport" lock or pin?

 

[Dunno]

Yes. Not locked. Thanks. FWIW, one of the stabilizer legs is still up after cycling the lever with no quick connects on hoses. I thought gravity would pull that down too.

 

[DJ54]

Am I reading right that you didn't remove the pin from the ram end..?? Note I did say I purged my cylinder with pin removed. Depending on your compressors max. PSI, the best you'll get in force is psi X cylinder ID and not nearly enough to move much if still fully connected.

Most newer tractor hydraulic systems will push approx. 2500+ psi X the ID of cylinder makes a huge difference. Since you need to rebuild the cylinders before using, you'll need to disconnect the ram end to do it, using air now to purge cylinders would make it a lot less messy.

I have no idea what type of gland nut the cylinders have on them but found on my old Case 480C it's easier to rebuild in place, and not remove. The gland nuts on it need to be torqued to 400+ ft, lbs. so leaving it pinned on the hoe was the best way to hold it.

If you've never rebuilt a cylinder, I highly suggest getting a set of the internal seal tools that collapse the internal seal to install. Makes it so much easier..!! Didn't even know they made such a thing when I did my first one. Got mine off Amazon.

I rebuilt one of the swing cylinders on my 480 last Fall and found the piston bolt needed to be torqued to 400+ ft. lbs. too. Easy to do with my impact wrench and used the Permatex "orange" thread locker. I have a buddy who is a heavy eq. mechanic for a local dealer, and he told me that's what they use. Good enough for them, good enough for my old Case.