The CAT 1R-1807 oil filter was designed to function vertically so it lacks an anti-drain-back valve. When the CAT oil filter is mounted on a Duramax it is angled horizontally. Without the anti-drain-back valve, dirty oil flows back into the internals every time the engine is shut off.
| Attributes | |
| Country of Origin (Primary) | CN |
| Hazardous Material Code | N |
| Life Cycle Status Code | Available to Order |
| NAFTA Preference Criterion Code | B |
| SDR Required Flag | N |
| GTIN | 00840171205138 |