Excavator bucket

YotaOnRocks said:
I was thinking that maybe since the cylinder is leaking externally that an internal seal might be leaking some causing it to loose pressure and not be able to lift the machines weight
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If it's leaking externally, that is the side that would be holding pressure when you try to lift the machine, so that's (probably part of) the reason it's leaking down. How bad is the external leak? Stays wet? Steady drip? Small stream?
 
jeepinmatt said:
If it's leaking externally, that is the side that would be holding pressure when you try to lift the machine, so that's (probably part of) the reason it's leaking down. How bad is the external leak? Stays wet? Steady drip? Small stream?
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Stays wet, I don't think I've seen a steady drip or small stream.
 
YotaOnRocks said:
Stays wet, I don't think I've seen a steady drip or small stream.
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If that's the case, there's probably some internal leakage going on in the cylinder. Either case is kinda the same outcome: cylinder needs to be rebuilt.
 
jeepinmatt said:
If that's the case, there's probably some internal leakage going on in the cylinder. Either case is kinda the same outcome: cylinder needs to be rebuilt.
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Is rebuilding it as simple as it seams or is it the sort of thing where I should just pay the man.
 
YotaOnRocks said:
Is rebuilding it as simple as it seams or is it the sort of thing where I should just pay the man.
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Depends on how big the cylinder is. Usually the hardest part is getting the collar off. Ive done a few myself. Usually takes a little heat.
 
I rebuild cylinders often. They are stupid simple. Get a kit and let me know if you need assistance.

You can also plug in a guage and check relief pressures against the pressures listed in your manual. (Hopefully there are schematics in there)
 
Jeff B said:
I rebuild cylinders often. They are stupid simple. Get a kit and let me know if you need assistance.

You can also plug in a guage and check relief pressures against the pressures listed in your manual. (Hopefully there are schematics in there)
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It appears the gland nut uses a spanner wrench to remove it, there are 3 notches around the nut. Is there a universal tool that should work? Thanks
 
YotaOnRocks said:
It appears the gland nut uses a spanner wrench to remove it, there are 3 notches around the nut. Is there a universal tool that should work? Thanks
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YotaOnRocks said:
It appears the gland nut uses a spanner wrench to remove it, there are 3 notches around the nut. Is there a universal tool that should work? Thanks
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Yes.
41249_400x400.jpg

Also hopefully it's only the cylinder but the valves might be worn out too. If there's an external leak cylinder needs rebuilt anyway. Jeff b is right about checking pump pressure as it should definitely pick itself up, I've got a 121-3 service manual I'll see if it gives any numbers.
 
Look through the manual online here is what i found
Screenshot_20200902-213448.png
Screenshot_20200902-213859.png
 
YotaOnRocks said:
It appears the gland nut uses a spanner wrench to remove it, there are 3 notches around the nut. Is there a universal tool that should work? Thanks
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As stated the pipe wrench is the way to go if you don't have the tool. you will also need a pick set and a camera. take a good pic before you remove the seals, they only work when installed properly.
 
Jeff B said:
As stated the pipe wrench is the way to go if you don't have the tool. you will also need a pick set and a camera. take a good pic before you remove the seals, they only work when installed properly.
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I'm a bit amused that you went from pipe wrench to pick set. Large, wrong tool to small, correct tool quickly in one train of thought :lol:
 
jeepinmatt said:
I'm a bit amused that you went from pipe wrench to pick set. Large, wrong tool to small, correct tool quickly in one train of thought :lol:
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don't forget the camera for bad memory. :)
 
Do I test the pressure at the cylinder in question or can I put a gauge on a quick connect and check at the thumb line? Or should I be testing somewhere else? Thanks for all the help guys, maybe by the time I get this thing squared away I'll half way understand how to troubleshoot problems on it.
 
YotaOnRocks said:
Do I test the pressure at the cylinder in question or can I put a gauge on a quick connect and check at the thumb line? Or should I be testing somewhere else? Thanks for all the help guys, maybe by the time I get this thing squared away I'll half way understand how to troubleshoot problems on it.
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Just "T" a gauge in line and run over relief. If it's not in the spec. then adjust to spec. You will have to run the cyl all the way in one direction until it stops moving then keep it trying to move when you read the gauge. Make sure you are on the side that the oil is going into.

Does this have a test port manifold? If so, I would get the test port fitting and check everything there.


If it's driving well, don't worry about the propel pump. You can just verify the charge pressure at idle and at WOT.
 
Well now that I seem to have gotten the hydraulics squared away I found an excessive amount of play in the swing knuckle (correct terminology?). I ordered all new bushings, pins, thrust washers, and shims for the swing knuckle and they arrived this week. Any suggestions or words of caution before I pull the boom off to fix it? I have put all the bushings in the deep freezer but I'm concerned I won't be able to drive them in by hand. Planning to extend boom and lay it as flat as it goes and then hoist it with a strap from forks on the skid loader.
 
Post up a few pics of the pin your going to remove. May be easier to make a push tool with a welder and threaded rod. These can be super difficult depending on the wear, if the bushings did their job, should not be that bad. If the pin is worn to the point of having shoulders or is stuck, may be a bitch.
 
Jeff B said:
Post up a few pics of the pin your going to remove. May be easier to make a push tool with a welder and threaded rod. These can be super difficult depending on the wear, if the bushings did their job, should not be that bad. If the pin is worn to the point of having shoulders or is stuck, may be a bitch.
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I am at work so I can get better pictures this evening if needed. The bushings and pins circled in red are the ones that are sloppy. There are 6 bushings and 2 pins. I plan to remove the pins circles in blue and pull the boom, after disconnecting the hydraulic lines.
115913135_891623727982670_3521716626467266417_o~2.jpg
 
Incase it helps here is a parts diagram showing everything except the 2 bushings that go into the swivel frame.
Screenshot_20201017-101533.png
 
Pull the blue circled pins first then the knuckle to frame.

Looks like it should come apart easily.
 
Jeff B said:
Pull the blue circled pins first then the knuckle to frame.

Looks like it should come apart easily.
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Do you think I will be able to knock the new bushings in by hand or do I have to invest in something like a hollow ram to install them.
 
You will probably need to fashion some type of driver. Are the oilite bearings of hard bushings?
 
Jeff B said:
You will probably need to fashion some type of driver. Are the oilite bearings of hard bushings?
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I'm honestly not sure. The 2 bushings going in the frame side are bigger and are brass colored. All the other bushings that go in the knuckle look steel.
 
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