Roadmaster Estate Wagon V8-350 5.7L VIN P SFI (1996)
Coolant: All Technical Service Bulletins
Heater - Inoperative/Rust in System
File In Section: 06 - Engine/Propulsion System
Bulletin No.: 01-06-02-003
Date: May, 2001
TECHNICAL
Subject:
Rust in Coolant System, Heater Inoperative, Blows Cold Air
(Flush Coolant System)
Models:
1996 Buick Roadmaster
1996 Cadillac Fleetwood
1996 Chevrolet Caprice, Impala SS
with 4.3L or 5.7L V8 Engine (VINS W, P - RPOS L99, LT1 )
Condition
Some customers may comment that the heater is inoperative, blows cold air, the engine may exhibit an overheat condition or the coolant reservoir has
rust in it.
Cause
Excessive aeration of the coolant under certain conditions may contribute to the formation of a rust-like material in the coolant system.
Correction
Flush the coolant system using the repair procedures below.
Parts and equipment required/suggested for this correction are listed below:
Important:
It is recommended the vehicle be placed in a position where the following is available:
^
A sanitary sewer -- not a storm drain, etc.
^
Running water
Caution:
Do not remove the coolant recovery reservoir cap while the cooling system is hot. Serious personal injury may result. Only remove the cap from a
cool engine.
1.
Drain and properly dispose of the coolant. Refer to Draining and Filling Cooling System in the Service Manual.
Important:
You can use various methods and equipment to flush the cooling system. If special equipment is used (such as a back flusher) follow the
manufacturer's instructions. However, always remove the thermostat before flushing the system.
2.
Remove the thermostat. Refer to Thermostat Replacement in the Service Manual.
3.
Flush the entire cooling system with water only (including the radiator, pressurized coolant bottle and the heater core). Refer to Flushing in the
Service Manual.
4.
Back flush the engine and water pump with clean water until no debris is observed in the flushed water.
5.
Drain and properly dispose of the coolant/water. Refer to Draining and Filling Cooling System in the Service Manual.
6.
If the coolant recovery reservoir is stained, replace it with a new reservoir assemble, P/N 12528777. Refer to Coolant Recovery Replacement in
the Service Manual. A new cap comes with the reservoir assemble.
7.
If the coolant recovery reservoir is not stained, pressure test the reservoir cap and replace, if necessary, with P/N 25713160.
