* Rear Heater Core Hose(s): Conversion vans often have extensive rear heating systems. A hose connected to the rear heater core running near the passenger-side rear wheel well is a prime suspect. These hoses are often vulnerable to age, cracking, and rubbing against chassis components.
* Transmission Cooler Lines (if applicable): Many vehicles, especially larger ones like conversion vans, use the engine's coolant to cool the transmission fluid via a transmission cooler. These lines frequently run through the wheel well area and could be leaking. However, transmission fluid is typically reddish, not green (like most antifreeze), so this is less likely if the fluid is green.
* Radiator Hose (less likely): While less probable given the location, a severely deteriorated or damaged section of the lower radiator hose *could* potentially drip down and pool under the passenger-side rear tire. This is less likely because the hose is usually much further forward.
* Water Pump Leak (extremely unlikely): A water pump leak would generally show up much further forward under the engine compartment. While a significant leak could drip down, it's highly improbable it would pool specifically under the rear passenger tire.
To pinpoint the leak:
1. Visually inspect: Carefully examine all hoses and lines in the passenger-side rear wheel well area. Look for cracks, bulges, or stains.
2. Pressure test the cooling system: This involves pressurizing the cooling system with a specialized tool to locate leaks more easily. This is best done by a mechanic.
3. Check for other evidence: If the leak is minor and difficult to immediately locate visually, look for signs of coolant further up the vehicle's underside. Tracing the path of the leak can help narrow down the source.
Important Note: Antifreeze is toxic. Avoid prolonged skin contact and wear gloves when inspecting. If the leak is substantial, have it repaired immediately to prevent overheating and engine damage.
