1. Preparation:
* Safety First: Disconnect the negative battery cable. This prevents accidental short circuits.
* Gather Tools: You'll need a variety of wrenches (socket set, open-ended, adjustable), screwdrivers (Phillips and flathead), possibly a torque wrench, pliers, a drain pan, coolant catch basin, rags, and possibly a pump pliers.
* Coolant Drain: Allow the engine to cool completely. Locate the radiator drain petcock (usually at the bottom of the radiator) and carefully drain the coolant into a suitable container. There may be a drain plug on the engine block as well.
* Consult a Diagram: Find a diagram or picture of your specific engine's water pump and its surrounding components. This will greatly assist in understanding the process.
2. Accessing the Water Pump:
* Remove Belts: Loosen and remove the serpentine belt (or V-belts if it's an older system). Use the appropriate wrench sizes for the belt tensioner.
* Remove Fan and Fan Shroud (if applicable): This will vary greatly depending on your setup. You may need to remove the fan blades and shroud to get sufficient access to the water pump. Be careful – fan blades are sharp.
* Remove Accessories: Depending on your engine configuration, you may need to remove or loosen other components to gain access to the water pump, such as pulleys, brackets, or hoses. Take pictures as you go to help with reassembly.
3. Water Pump Removal:
* Disconnect Hoses: Carefully disconnect the upper and lower radiator hoses from the water pump. Have rags ready to absorb spilled coolant.
* Remove Pump Bolts: Identify and carefully remove the bolts holding the water pump to the engine block. These bolts can be stubborn; use penetrating oil if needed and work them loose gradually.
* Remove Water Pump: Once the bolts are removed, the water pump should come off relatively easily. However, it may be stuck due to corrosion. Gently pry it off if necessary, using a suitable tool to avoid damaging the engine block.
4. Water Pump Installation:
* Clean the Mounting Surface: Thoroughly clean the mounting surface on the engine block, removing any old gasket material.
* Install New Gasket: Install a new water pump gasket (included with the new pump) onto the engine block.
* Install New Water Pump: Align the new water pump and carefully install it onto the engine block. Tighten the bolts to the manufacturer's specified torque – this is critical. Do not overtighten.
* Reconnect Hoses: Reconnect the upper and lower radiator hoses. Use hose clamps to secure them.
5. Reassembly:
* Replace Accessories: Reinstall any accessories you removed earlier (fan, pulleys, brackets).
* Replace Belts: Reinstall the serpentine or V-belts, ensuring proper tension.
* Refill Coolant: Carefully refill the cooling system with the correct type and amount of coolant (usually a 50/50 mix of coolant and distilled water).
* Bleed the System: Bleed any air bubbles from the cooling system by running the engine with the radiator cap off until coolant flows steadily, then replace the cap. Consult your repair manual for bleeding instructions specific to your engine.
6. Testing:
* Run the Engine: Let the engine run for a while, monitoring for any leaks. Check the coolant level and temperature gauge.
* Check for Leaks: Carefully inspect all connections and hoses for any leaks.
Important Considerations:
* Repair Manual: Again, a repair manual specific to your 1973 Dodge 360 motorhome is essential. This will provide detailed instructions, torque specifications, and diagrams specific to your vehicle.
* Professional Help: If you're not comfortable performing this repair yourself, it's best to take your motorhome to a qualified mechanic. This is not a beginner-level repair.
This is a general guide; the specific steps may vary slightly depending on your motorhome's model and year. Always prioritize safety and consult a reliable repair manual for accurate and detailed instructions. Improperly performing this repair can lead to engine damage.
