Dribbling water and wet carpet make for grouchy Mustang owners. Heater core replacement is enough to make you groan, especially in the post-1966 cars with air conditioning. Even with proper maintenance and care, some heater cores are destined to failure. This was the case with the core of this 1966 GT hardtop.
Without warning--as is usually the case--it just ruptured in a parking lot. So with a pocketknife and flat-blade screwdriver in hand, the owner did the Mustang loop with the heater hose. Then, he filled the radiator with water and limped his injured pony home. This is where we came into the picture.
The gluttons that we are, we decided you need to get a peek at how to replace the heater core and the foam kit on a vintage, nonair- conditioned Mustang. For the heater core, we went to the local parts store and snagged one off the shelf. As for the seal kit, we went to Purely Pony in Tampa, Florida.
So, put on your work clothes and dig in. There's a heater core to remove, and it isn't coming out without a struggle.