Cooling question for the masses

[70Custom10Nut]

Starting with a little background. I'm stationed in Germany. My truck is with my son is SC. This past winter he took the truck to Automotives class and flushed the cooling system for me. Now he's saying that the temp gauge reads that it's overheating, the heater core leaks from the bottom fitting, and the bottom of the radiator is leaking. Will a heater core leak to the outside? I've always known that coolant inside the cab floor to be the telltale sign for a bad one. Does flushing system effect the temp sending unit and/or the water pump? He's already changed the thermostat. The radiator is a no brainer, but can anyone in the Columbia SC area recommend a reliable radiator repair shop? It's kinda frustrating trying to fix things over the phone.
Any advice would help, thanks

[WadmalawJoe]

I don't know any shops up that way, but I'm sure someone will chime in.
The heater core is inside that box that's inside the engine bay, so it will leak in the engine bay area. I think a new heater core is like $35. The hardest part about changing it is getting to the bolts under it between the fender and the box.
I'm thinking with the leaks you may be getting air in the lines as well and causing a higher temp reading. Is there a fan shroud in place?

[70Custom10Nut]

Thanks for the insight. Yes the shroud is there and a working clutch fan. The frustrating thing is that prior to the flush, there were no problems, and now that I'm over here in Germany, I can't troubleshoot it in person. The heater core issue may give me justification to get my Old Air unit that I've been considering for years, or at least the in-cab unit do away with the factory one under the hood.

[GASoline71]

Since the heater cores are located ij a "box" inside the engine bay, most of the leaks will come out of the bottom hole of the box that the lower heater hose goes through. Replacing them isn't really all that hard, but you will probably have to remove the hood and passenger side front fender.

If it's the original 40 year old radiator, no amount of flushing will get all the crud out of it. Might be time to go ahead and upgrade to a new 4 core radiator.

Gary

[Andy4639]

This is what happens 99% of the time when you flush one. It will knock all the crud loose and it will cause all kinds of weird readings on the gauge. I would replace it and take everything a part off the fire wall and a new heater core is less than $50.00 a new radiator shouldn't be much over $200.00 if that much. Clean everything up good and filler back up with a good mix.
Flush the motor good to while it's all a part also and get any crud out of the water jackets that was knocked loose.
Get the auto class to do it all if they will.

[70Custom10Nut]

Well it's settled then. The son will have a weekend project. Thanks to all for the advise.