My truck is leaking water between the firewall on the right side of the truck. I can't see exactly where its coming from so I think its the heater core. It doesn't leak allot but enough to know there is a problem. Is this something that can be fix in a home garage with general tools or do I need to take it to a mechanic. I did the heater core on my 75 blazer but this looks to be a challenge. Any advice appreciated.