* Difficulty: This is a very difficult job, rated as advanced for most DIYers.
* Time Commitment: Expect to spend several hours, potentially a full weekend or more, depending on your experience.
* Tools: You'll need a complete set of metric and standard sockets, wrenches, screwdrivers (Phillips and flathead), pliers, a good set of automotive-specific tools (possibly including a special heater core removal tool), and potentially a shop manual specific to your year and model truck.
* Safety: Disconnect the battery's negative terminal before starting any work on the electrical system. Use caution when working with coolant, as it can be corrosive. Wear safety glasses.
General Steps (This is not an exhaustive guide, and details will vary depending on your specific truck's configuration):
1. Research: Obtain a shop manual specifically for your 1986 Chevy Silverado. This is crucial; it provides detailed instructions, diagrams, and torque specifications. Online forums dedicated to Chevy trucks may also offer helpful advice and pictures from others who've done this repair.
2. Preparation: Drain the coolant from the engine. This is essential to minimize coolant spills during the repair. Locate and disconnect the heater hoses.
3. Dashboard Disassembly: This is the most labor-intensive part. You'll need to carefully remove various components of the dashboard to access the heater core. This usually involves removing the glove box, radio, steering column shroud (possibly), and potentially other interior trim pieces. Take pictures as you go to aid in reassembly. Expect to encounter a variety of screws, clips, and fasteners.
4. Heater Core Access: Once the dashboard is sufficiently disassembled, you'll be able to access the heater core housing. This often involves removing the HVAC blower motor and potentially other components.
5. Heater Core Removal: This can be tricky. The core is usually held in place with several clamps or clips. A specialized tool may make this easier, but careful work with pliers and screwdrivers might suffice. Be prepared for coolant leakage; have rags and a catch pan ready.
6. Heater Core Installation: Install the new heater core, ensuring it's properly seated and all connections are secure.
7. Reassembly: Carefully reassemble the dashboard and other components, ensuring all screws, clips, and fasteners are correctly installed. Double-check all connections.
8. Refill and Bleed: Refill the cooling system with the correct type and amount of coolant. Bleed the air from the system to prevent overheating.
Important Considerations:
* Climate Control System: Understanding your truck's climate control system's operation is essential. You may need to carefully detach and reattach vacuum lines and electrical connections.
* Vacuum Lines: If your truck has vacuum-operated controls, pay close attention to their routing and connections; incorrect reassembly can cause malfunctioning HVAC controls.
* Professional Help: If you are uncomfortable with this level of automotive repair, strongly consider taking your truck to a qualified mechanic. The cost of professional repair might be less than the cost of potentially damaging your truck through an improper repair.
This is a highly simplified overview. The specific steps and challenges will vary depending on the exact model of your 1986 Chevy Silverado. Refer to a shop manual for detailed, model-specific instructions. Attempting this repair without the proper guidance could lead to significant damage to your vehicle.
