Caterpillar 320 excavator boom cylinders

[JRuffryders0930]

I have caterpillar 320 excavator that I have the boom hydraulic cylinders leaking and need to install a new seal kit. My question is are these the cylinders that have to be pressed in or is it an easy slide out and slide in. Any help will be appreciated. Thank you

 

[mikebramel]

You will need to compress the teflon piston seal on installation. The hardest part will be removing the piston nut. Depending on if it has been done before you will need 1000-6000ftlbs to remove and don't overlook the sec screw

 

[06Pete]

When I had my 320 cylinders rebuilt the guy told me it took the big torque multiplier and estimated 29,000# to break the nut loose I think the torque spec was 12,000# but don't quote me on that. In my opinion I would take them to shop I rebuild smaller ones myself but just not worth getting hurt over when I don't have the right tools. I think it was about $1000 for labor the parts and they also had a few spots on the chrome that they re-glazed to. I don't think any part is pressed in just needs to be torqued right and also should use a new nut each time.

 

[mikebramel]

Torque spec is 3500. At 12,000 you would have a Twizzler LOL

 

[mikebramel]

If you don't have the tools for piston removal. I have seen shops cut the nuts off and install new nut with red lock tite.

 

[06Pete]

I don't know but I can get 3500 with a small multiplier and pipe on the breaker bar this shop had a huge multiplier and a hydraulic wrench on it to break it loose said the nut had some rust on the threads is why it took so much for the one. I would have to check with cat on the torque spec that seems light to me on a 320 I know my 315 was much less when I had it done.

 

[Nige]

Torque for assembling the boom cylinders depends on which exact model of 320 you have - there are literally hundreds. Typically on the later models where the piston screws on to the rod then the Nyloc nut goes on after it the torque figures are around 800 ft.lb. for the piston and 1400 ft.lb. for the nut.