Cracked Hydraulic Cylinder from Caterpillar’s Largest Grader | Weld Repair

When hydraulic cylinders from Caterpillar’s largest grader show cracks around the trunnion welds, it’s time to find out how serious the damage really is. These blade lift cylinders from a CAT 24M grader arrived in the workshop showing cracks around the trunnion welds. Before any repair can begin we need to find out how far the damage has travelled and whether the cylinder barrels themselves are cracked. The first step is stripping the paint away with a wire wheel so the weld area can be inspected properly. The barrels are then set up in the lathe and the original weld material is machined away to expose the base of the trunnion and reveal the true extent of the cracks. If the cracks have travelled into the barrel the repair becomes much more serious and the cylinders may need to be re barrelled. Fortunately the inspection shows the damage is limited to the weld area, meaning the barrels can be repaired rather than replaced. With the inspection complete it’s over to the welding area where the welds on either side of the trunnion that join it to the barrel are welded up using the WIA 500i welder. Additional weld layers are added to help distribute the load and reduce the chances of the weld cracking again in the future. The welding process throws up a few challenges along the way. The first repair pass on both cylinders develops porosity caused by contamination and moisture around the trunnion area, forcing the welds to be completely ground out and redone before the repair can continue. On the first barrel things get even more interesting as Kurtis starts encountering contamination higher up the trunnion, leading to repeated blow backs during welding. And as expected the welding also affects the cylinder bore. The heat affected zone can slightly shrink the bore, creating tight spots that will damage seals if left unchecked. To correct this the barrels are moved to the Sunnen HTA 4100 horizontal honing machine where the bores are measured and carefully honed to remove the tight spots and restore the correct surface finish. With the cracked weld repaired and the barrels honed back to spec, these blade lift cylinders are ready to go back to work on Caterpillar’s largest motor grader. If you enjoy these types of repair jobs, check out more hydraulic cylinder rebuilds and machining work from our workshop: https://www.youtube.com/playlist?list=PLUzFN5xVei7UYoaZ3wuxKxCXM-7e9AdPv Join our channel: We upload new videos every Friday at 5pm AEST! If you want to see more of our videos click LIKE & SUBSCRIBE! You can subscribe to our channel here: https://bit.ly/ceesubscribe Want Early Access & Ad Free videos?? Join our Patreon Community: https://www.patreon.com/cuttingedgeengineering Official CEE Merch shop: https://www.ceeshop.com.au Check out our CEE Amazon store and explore our favourite finds that we use in the workshop: https://www.amazon.com/shop/cuttingedgeengineeringaustralia To see more follow us on online here: TikTok: https://vt.tiktok.com/ZSdHhtN4h/ Instagram https://instagram.com/cutting_edge_engineering Facebook https://www.facebook.com/cuttingedgeengineeringaustralia/ About Us: We're a down-to-earth real life machining and fabrication workshop in Australia. We specialise in helping business in mining and earthmoving to keep their machines running smoothly. We love working on broken parts and the bigger the better! We upload new videos every week showcasing machining, welding, line boring, honing and all the other awesome stuff that goes down in our workshop. Learn how we tackle different projects and see the satisfaction of creating something useful. Subscribe to stay updated on our latest jobs and projects! Follow us on Patreon for even more content and behind-the-scenes glimpses or find us on Tiktok, Facebook and Instagram for a chance to connect with us. #australianmachinist #machineshop #machinist