John Deere 420 loader cylinder rebuild question

[swampbuggy77]

I have a 420 loader with serial number 9759 with a bucket cylinder that is leaking through the small hole in the side of the cylinder - see attached picture. Based on the parts diagram, it looks like this hole is where the Tie Band/Wire lock is inserted, but this is my first cylinder rebuild...

A couple questions:
1. Is it normal for a leaking cylinder to leak through the wire lock hole in the side? Is that an indication of larger problems, or just need a rebuild kit?
2. I found a lot of rebuild help for the spring clip-type cylinders, but struggling to find instructions on how to open up this one with the tie band/wire lock.

 

[ptsg]

I think you'll just need the rebuilt kit. Nothing major other than old seals that are starting to fail. The reason it's leaking there, is because the O-ring sealing the gland and the barrel failed.

It might actually be a good think as it kinda keeps things lubed. Those type of glands held in place with the wire lock can get corrosion between the gland and barrel, causing all sorts of issues to take apart.

Here is a video showing the disassembly of a similar style cylinder. Hopefully it helps you getting through this repair. Starts at around the 12:15 time stamp.

 

[jthibodeau89]

I just did this on my early model 430 loader last week. Need to lift the free end of the wire above the edge of the slot and rotate the gland to feed the wire out. In my case both the loop and the tang end that keys into the gland were broken off. A little more difficult, but just took patience and some mini vice grips to pull the wire. In my case it was easier to leave the cyl end pin attached to the boom until the rod was out.

I recommend getting new lock wires, though the old can be reused if not damaged. Note that the length of the wire and the joggled end sets the clocking of the gland oil port. If the gland is free to rotate, the tang end is broken off. The tang is required to roll the wire back in.

The lock wire can raise a burr on the edge of the mating grooves on the gland and cylinder. I had to use a slide hammer motion to get the gland out. I cleaned the gland burr up with a 400 grit diamond file. I left the cylinder alone so that i didn't scratch the bore.

The 430 cyls are NLA, so i will be doing a generic cylinder retrofit in the future due to damaged rods. Found workable replacement cyl's for $70 ea. The 420 cyl are longer retracted length due to the direct attachment to the holder. The 300x holder is a cast steel replacement for the 420 holder, but may need rod end width modification.

I just retrofit 300cx holders and cast links onto my 430 loader. I had to narrow the rod ends on the 430 bucket cyls as well.

 

[swampbuggy77]

jthibodeau89 - curious, the new lock wire in your picture has both ends bent. Which end is the end you start with to feed in? I thought one end was bent, the other end should be straight?

 

[swampbuggy77]

I think you'll just need the rebuilt kit. Nothing major other than old seals that are starting to fail. The reason it's leaking there, is because the O-ring sealing the gland and the barrel failed.

It might actually be a good think as it kinda keeps things lubed. Those type of glands held in place with the wire lock can get corrosion between the gland and barrel, causing all sorts of issues to take apart.

Here is a video showing the disassembly of a similar style cylinder. Hopefully it helps you getting through this repair. Starts at around the 12:15 time stamp.

Very helpful video, thank you for sharing!

 

[jthibodeau89]

jthibodeau89 - curious, the new lock wire in your picture has both ends bent. Which end is the end you start with to feed in? I thought one end was bent, the other end should be straight?

The single 90 tang at the bottom of the photo is placed into the counterbore in the gland to feed in the wire. The rectangular section at the top of the photo is the lock that sets orientation. It's length matches the slot in the cylinder.