Attempting to avoid disconnecting the accumulator significantly increases the risk of:
* Damaging the AC system: Accidental punctures or leaks are far more likely if you're working in a cramped space without properly isolating the AC components. This will result in expensive repairs or a complete AC system recharge.
* Spilling refrigerant: Refrigerant is harmful and environmentally damaging. Even a small leak can necessitate professional evacuation and recharge.
* Increased difficulty and time: Trying to maneuver around the accumulator will likely take longer and be more frustrating than simply disconnecting it properly.
The safest and most efficient method almost always involves disconnecting the AC accumulator. This involves:
1. Recovering the refrigerant: A professional AC shop or a person with the proper equipment should evacuate the refrigerant from the system before disconnecting anything. Attempting this without the proper equipment is dangerous and illegal in many places.
2. Disconnecting the accumulator: Once the refrigerant is recovered, the accumulator lines can be carefully disconnected.
3. Replacing the heater core: This usually requires removing the dashboard or significant portions of it.
4. Reconnecting the accumulator: After the heater core is replaced, the accumulator is reconnected, and the system is recharged with refrigerant.
In short: While theoretically possible to replace the heater core without disconnecting the accumulator, the practical challenges, risks, and increased difficulty make it strongly discouraged. The extra time saved is negligible compared to the potential for costly damage and safety hazards. If you lack experience with automotive AC systems, leave it to a professional.
