2000 Chevrolet Blazer Oil Cooler Line

You need to ensure that the plastic cap is fully seated against the fitting.

You need to disengage the plastic caps from the quick-connect fittings. Pull the caps back along the pipe, and pull on one of the open ends of the retaining ring to rotate the retaining ring. Then you need to rotate the retaining ring around the quick connector and discard the retaining rings, and you also need to remove the engine oil cooler line from the quick connector fitting at the radiator. Pull the lines straight out from the connectors. After that, you need to clean all of the components in a suitable solvent and dry them with compressed air. Finally, you need to inspect the fittings, the connectors, the cooler lines, and the cooler for damage, distortion, or restriction.