7040 Diesel Piston Ring Compressor 5.4" Bore Tool for Cummins ISX, Caterpillar 3400, C-15 and PT-7040 Red. ✔ Works on Cummins ISX, Caterpillar 3400 and C-15 5.4" Bore without twisting. • Cummins ISX, Caterpillar 3400 and C-15 5.4" Bore.