CAT 963 Full Hydraulic Build

[rockNmayhem]

Well many of you guys may remember the Cat tracked loader that Brian had built. I recently acquired it and have started to do some fiddling with it. When I received it the genius people at the post office couldn't read every single side of the box that said which way was up and the model was left upside down to let all the hydraulic fluid leak out. Brian did and excellent job of packing it but there was still a good amount of leakage. Anyways I started to tear into it like a kid at christmas and found all the inner workings were in tact and about ready to go. First things first I cleaned it up and got all the fluid off of the electronics and dried everything out for the night and then broke into it again the next day.

Well in the process a couple of lines were pulled off so I got them back on and fired up the motor with my new esc installed and decided to see what this loader could do. Well to my surprise the bucket worked flawlessly dumping but was a little slow going up so I bled it both directions and it helped it out. Next was onto the arm rams. Now here is where I started to hit a problem.

I began lifting the arm and it got almost all the way up then stalled. I figured I had some air in them as well so I cracked the return lines at the time and got the arms all the way up. I rehooked up the lines and started to send the arm down when all of a sudden I realized it had stopped and all the fluid was pouring out the front seal of the right arm. I couldn't believe it. I didn't have that much pressure behind it and it started leaking. So I tinkered with the pressure and no matter how low I set it through my esc I still had a leak.

Well anyways after spending a few days thinking about it I decided instead of contacting the original mfg of the hydraulic cylinders I would just take time and build my own. So now that we are caught up to today I finally got some time to start on my own setup. Anyways here are a few pics of todays progress on one of the arm cylinders. Now I'm not sure how many seals other models have in their cylinders but I decided to go with four simply to have insurance that I would have no leaks.

I started out by simply making the new cylinder cap and creating o-ring grooves by building multiple layers with offsetting sizes to press fit in and seal up tight on the shaft.





I then took a small c-clamp and mounted it into a small vise and used it as a small arbor press. I am pressing all five pieces together to build the cap in this picture.



Once all the pieces were pressed together I installed the two o-rings in the end cap. There is an inner oil seal and an outer dust seal just inside the front face to keep debris out of the cylinder itself and to help protect the shaft a bit better.



I then turned out a shaft for the cylinder and over sized it by just a few thousandths so I was guaranteed a good seal.







Once I polished up the ram itself and threaded both ends I started making the inner sealing rings and mounted the assembly up to the ram.



My final part for today was cutting the body of the cylinder and honing and polishing the inside so I get a good seal all the way and make sure that the ram slides smoothly while still sealing both directions. I added a little oil to both sides of the ram and pulled it both directions to find out that my seals were holding up and I had no leaks.





Now all I have left to do is build the back cap and assemble the cylinder and hook lines to it. I hope to be able to run these rams up to the 165psi I was getting out of the pump without having anything blow out.

Hope you guys like the progress so far and I hope to have some more updates soon. I really plan on having this done and running good by St. Louis so if all goes well I believe that it may be possible to have it working by next weekend.

Thanks for looking.

Tyler