Description: This product is a great fit for GM vehicles from 1999 to 2023 with LB7/ LLY/ LBZ/ LMM/ LML/ L5P 6.6L Duramax engines. The part number is WCF100155. It replaces the failure - prone plastic factory GM Heater Core Firewall Coolant Fitting. It's a billet direct - fit replacement with a 5/8' barb connection. It's more resistant to heat and vibration, has a double O - ring seal, and a clear anodized finish to resist corrosion.

Using this Duramax coolant heater core firewall fitting is easy. Just remove the old, plastic factory fitting and replace it with this billet one. Make sure to connect the 5/8' barb properly. When installing, be gentle to avoid damaging the double O - ring seal. For maintenance, check the fitting regularly for any signs of wear or corrosion. If you notice any issues, it's a good idea to replace it right away. Keep it clean to extend its lifespan. This fitting is built to resist heat and vibration, but extreme conditions may still affect it. So, try to avoid exposing it to excessive heat or rough vibrations for long periods.