Leak Check Test with A Black Light

Add dye to the transmission fluid. Use one 30 ml (1 oz) of dye solution for every 3.8L (4 qt) of transmission fluid. Add additional transmission fluid until it is at the correct level. Such dyes can be used to determine whether an engine fluid or transmission fluid leak is present, or if the fluid in the transmission fluid cooler leaks into the engine coolant system. An ultraviolet light must be used to detect the fluorescent dye solution.

1. Clean any transmission fluid from the top and bottom of the torque converter housing, front of the case and rear face of the engine and oil pan. Clean the torque converter area by washing with a suitable non-flammable solvent and blow-dry with compressed air.
2. Wash the torque converter housing and the front of the flexplate. The torque converter housing may be washed using clean solvent and a squirt-type oil can. Blow-dry all washed areas with compressed air.
3. Use the scan tool and monitor transmission fluid temperature. Start and run the engine until the transmission reaches its normal operating temperature. Shift the transmission through all gear ranges to make sure the dye has circulated through the transmission. Using a suitable tool, observe the back of the cylinder block and top of the torque converter housing for evidence of transmission fluid leakage. Observe the front of the flexplate, back of the cylinder block (in as far as possible) and inside the torque converter housing and front of the case. Run the engine until transmission fluid leakage is evident and the probable source of leakage can be determined. Repair as required.