This is in reference to Daewoo Forklift G20S-3 using a Hercules 2.7l engine. We have just dismantled an engine of this model as it was having heavy compression leakage. When we removed all the pistons from the bore we found that in Piston # 1 + 3 the wall between piston ring 2 & 3 had broken and come away from the piston. Does anyone have any idea as to what could be the reason for this failure. The engine was being operated on LPG.