Piston disassembly help and ideas

[bd53bz2]

Heres the story... Digging trench yesterday and all going well until I used the TLB to reposition the machine. The dipper piston blew the nut off the rod. I rebuilt this cyclinder last year. (new seals) What I can't do is get the piston seal past the retaining wire groove. The groove is chamfered going in but not out. Can't use air, tried small diameter wire to fill groove --- all NG. Right now, I open for ideas.

 

[SSdoxie]

Never done this but just and idea. Get a toggle bolt, large as possible but will fit through the piston, then drill hole for bolt diameter in piece of steel to go across end of the barrel. Bolt goes through the steel, thread spring toggle back on and slide it down in the pistion. Start tightening the bolt using it as a puller.

 

[bd53bz2]

Good idea but the piston is already starting to stick out of the bore when the seal hangs in the groove.

 

[hosspuller]

When I resealed my Deere BH cylinder, the kit included a filler tool. It was teardrop shaped to fill the groove and allow the seal to pass. A cylinder shop should have the material for you.

 

[dfkrug]

Good idea but the piston is already starting to stick out of the bore when the seal
hangs in the groove.

Can you push the piston back into the cylinder?

If so, some seal kits have a filler ring to put in the troublesome groove. Or you can fill the groove with
Bondo-type body filler, let it harden, then remove it after you get the piston out.

 

[crackerjack222]

I have replaced the seals on two pistons on my JD 4430 fel. The first time, I put the plastic ring in the groove but still could not get the piston out of the cylinder by pulling on it by hand. I chained the cylinder to a big oak tree, chained the shaft to the front of my truck and backed up pulling the piston out of the cylinder. I put some old towels down to catch the piston on. The second smaller cylinder came out using the amstrong method.
I have another cylinder leaking now, but I think I will take it to the hyd shop to let them do it.

 

[wdchyd]

Can you push the piston back into the cylinder?

If so, some seal kits have a filler ring to put in the troublesome groove. Or you can fill the groove with
Bondo

x2....^^^^^^

 

[bd53bz2]

Thanks to all. I was able to get it. With the piston out to the groove I used a piece of mig wire, slid it through the retaining wire slot. A rubber plug in the center of the piston (knocked the air down to 50lb.) Tightened wire, while moving the piston and she popped. The nut did back off after my last rebuild. I used Blue Loctite last time. NEW lock nut and RED Loctite this time.