Peterbilt Coolant Tube. Peterbilt 357 379 Upper Coolant Tube Fits Detroit 60 07-06902 Stainless Steel. Peterbilt 357 379 Lower Coolant Tube Fits C7 C12 3176 Stainless Steel # 0706858. Peterbilt 357 379 Stainless Upper Coolant Tube Cat C15 C16 OE# 0705723 Pre 1993.