Flow Test
- Disconnect both hoses from the oil cooler pipes. Connect the oil cooler feed pipe (front connector) to the transmission for normal flow.
- Clip the discharge hose (5) onto the empty oil drain container. (Scheme 173)
- Confirm the transmission is filled with ATF. See «CHECKING FLUID LEVEL & CONDITION»(/chevrolet/suburban-k2500/gmt800-2000-2006/remont/automatic-trans/#automatic-transmission-4l80-e-servicing).
- Start the engine with the transmission in Park range and run for 30 seconds after fluid begins to flow from discharge hose (5). A minimum of 2 qts. (1.9 L) must be discharged during this 30 second run time.
- If fluid flow is meets or exceeds 2 qts. (1.9 L) in 30 seconds, connect the oil cooler feed pipe to the front connector of the transmission.
- If fluid flow is less than 2 qts. (1.9 L) in 30 seconds, perform the following diagnosis: Disconnect the transmission oil cooler and line flusher discharge hose (5) from the oil cooler return pipe. Disconnect the oil cooler feed pipe at the radiator. Connect the flusher discharge hose (5) to the oil cooler feed pipe, radiator end. Clip the discharge hose (5) onto the oil drain container. Start the engine with the transmission in Park range and run for 30 seconds after fluid begins to flow from the discharge hose (5). A minimum of 2 qts. (1.9 L) must be discharged during this 30 second run time.
- If the amount of transmission fluid flow remains less than 2 qts. (1.9 L) in 30 seconds, inspect the oil cooler feed pipe, front connector, for restrictions or damage. If no condition is found with the feed pipe, front connector, inspect the transmission.
