Leak in heater core 88 mustang gt

[fred414141]

you can try a dose of radiator stop leak,there are a lot of different ones on the market.do consider running a cooling system cleaner first.and don't be tempted to go nuts and use more than 1 stop leak deal.if 1 attempt at using a 'put this in the radiator' product does not do the job,pull the core and replace it!