A work truck doesn't have to be cold on the inside-after all 'professional grade' should apply to your GMC heater core too, right? Right! However, a leaking GMC heater core, or a GMC heater core that's plugged up with years of sediment can cause a lot more problems than just leaving you cold on a frigid winter morning. That plugged up GMC heater core can cause dangerous pressure to build up under your dash, resulting in a burst GMC heater core-and hot coolant spraying all over underneath your dashboard. While not as dramatic, a leaking GMC heater core can slowly drip coolant all over your carpet, floors, and shoes, plus it can lower your engine's coolant level to the point where it overheats. All the while, you're suffering in the chilly weather because your failed GMC heater core doesn't put out enough, if any, heat. Don't bypass your GMC heater core-that's the easy way out, but it's also the wrong way to fix the problem. Install a new high-quality GMC heater core like the ones you'll find here. For installation, you'll definitely want a good shop manual; after all, replacing a GMC heater core isn't one of the easiest jobs in the world. However the factory has left some provisions to make shoehorning the new GMC heater core into place a little bit easier. An access panel or a piece of removable ductwork is usually provided to facilitate GMC heater core removal and replacement, but it may not be obvious without the proper instructions. Don't put off your GMC heater core replacement: Rust on the floorpans and moldy, mildewed carpet will be the result. Just get the right GMC heater core from us and pick up a GMC repair manual, and you'll have the heat back on before you know it.