Radiator (1517C) Service Notice for 1994-1996 Buick Roadmaster, Cadillac Fleetwood, and Chevrolet Caprice/Impala SS
Due to model updates, there are variations in radiator replacements for 1994-1996 Buick Roadmaster, Cadillac Fleetwood, Chevrolet Caprice, and Chevrolet Impala SS models (part #1517C).
- The original, 1st generation, radiator design can be identified by two outlets on the coolant tank reservoir; one connected to the heater and the other to the radiator. This design was changed due to a frequently reported issue with the heating system. When the heater was turned on, the coolant was not reaching the required temperature to heat the vehicle cabin. The two-outlet coolant tank design essentially hindered heating performance because it allowed a constant flow of water into the coolant circuit. In April 1994, GM released a service bulletin, ‘GM TSB 431214’, with instructions on how to modify the original reservoir tank with a rubber boot over one of the outlets and a T piece in the heater circuit to prevent leaking from the second outlet connected to the radiator. With this modification, coolant is able to reach the required temperature to heat the vehicle cabin.
- Most aftermarket replacement radiators feature the 2nd generation design, with only one outlet on the coolant tank reservoir to the heater. These radiators are designed without an outlet to the reservoir tank.
Many of the 1st generation vehicle models on the road today have a modified coolant circuit as described above. Please refer to GM TSB 431214 (April 1994) for proper modification procedure and gpd Tech Tip #2 ‘Flush Procedure’. Please note to remove excess air from the system at the bleed nipple located near the throttle body on the passenger’s side.