I am digging/dredging 70 years' worth of sludge/sand/etc from a 20-acre pond. The CAT has been running well lately until today. There was a sudden "pop", the machine shook pretty hard, and the boom joystick made a grinding (?) sound. Everything works except the boom...I can track, slew, and use the thumb. I was in a rough wet spot but was able to track about 25 yards dragging the bucket to get the machine up onto the haul road/dam widening area for working on it. I have Yancey coming in the AM to check it out. See video below of the event...what do you think "let go"? I looked over structural things...pins, boom, hoses, etc. but nothing seems amiss. I suspect that noise from the left joystick area may be diagnostic to someone, but not me.
Boom cylinder blew a bolt at the ram. Or you cracked the pump. Watching again, don’t think it’s in the cylinder.
Interesting you don't often get to see machine fail. my guess would be something happened in main control valve possible blew a relief valve
The CAT mechanic hooked a pressure reader in and deduced the left side cylinder failed...possibly the bolt at the piston, like Harley said, I guess. He said the pressure (4500) was good. As a sidenote...They sent a young fellow to do the work, someone I haven't seen before. His 30' truck crane would not quite reach over the CAT to hoist the cylinder...about 3 feet short. I offered to use my Takeuchi TB370. We could have used it to hold and hoist from above the cylinder. But first, he wanted to get the base pin out. He had me position the bucket to block the base when the pin was removed, so it would not swing free. Apparently, he did not have me pulled closed enough because when he slid the pin out the cylinder dropped thru the gap, hit the track, shot to the other track and ended up laying diagonal from the right track base with the cylinder rod...all clean and shiny and smooth...on the left track. I did not know that he had already removed the retainer from the top pin and when the bottom swung out, it also slipped off the top pin, and the cylinder dropped straight down, hit the track, and shot over to the other track. It went right beside his leg but did not hit him. It would have been catastrophic if it did. Anyway, I called the CAT service supervisor and told him they need to check the cylinder rod closely for nicks or scratches. It was almost a very bad day. Now CAT has the cylinder and will check/repair as needed.
***! Very friggin lucky. Might need the tech to take some rigging classes.