I have a 1999 315BL with 11,000 hours on it. I bought it from the origional owner, who incedentally I did mechanic work for since 2002. Machine had a crack in the boom early 2000's and Caterpillar repaired the crack no charge. This repair can be seen in the photos attatched. 25 years later a crack developed on the bottom side of the boom, my question is there seems to be water coming out of the crack, is it common to have water in the boom? Seems like an odd spot to crack, is this a common issue for Cat? I have a welder coming monday, is there a prefered method to repair this? Is there an internal support in this area?
Previous Repair on top of boom by Caterpillar. Struggling with photos View attachment IMG_6035.jpeg
This shows old crack that was repaired years ago, and the current crack location below. View attachment IMG_6033.jpeg
Got a Serial Number.? It makes it easier to look for technical information. It also helps to see what type of boom it has fitted. Reach booms are typically more prone to cracking. I can say now that IMHO that boom is going to require a window cut into it in order to access the inside of the box section. Any repair done solely from the outside is doomed to fail, again IMHO. YMMV. Regarding your question whether or not there are any internal bulkheads in that area, you'll find that out when you cut the hole in it......
SN 3AW01622
Then the attached suits your machine. All 70 pages of it. Have fun........ Your particular machine does have a reach boom BTW.
You'll want to keep it in a heated space until you can get the water out of it. If it freezes hard enough it will swell and deform boom.
Nige, that is fantastic information, and exactly what I was looking for, thank you. And yes I agree about it being inside a shop, that is near impossible right now. I guess I am questioning if there is actually water in there or not. I may drill a hole in the boom to find out, not sure what else to do at this point, a 1/4 inch hole is less damaging than a boom full of water. The location of the project we are on is at 2000 feet, and a lowbed cant get within a few miles of us with the recent weather we have had.