TR6 TR6 Heater core plugged?

[Bruce100]

The PO of my 72 TR6 had removed the valve and plugged the threaded hole where the valve attaches and the lower heater hose. As the weather is getting cooler I decided to take a crack at it and see if it was just the valve. Put a new valve in, and tried it. Hot upper hose, lower hose not heating up much at all, no heat in car. Removed lower hose again from valve, no water coming out (engine stopped of course). Assume my heater core is plugged. Life is busy now, not sure I want to take it out of the car. Have seen various suggestions to backflush, as long as you watch the pressure. Before I just jump in and do this, what have you all discovered with unplugging heater cores?

 

[Gliderman8]

Not so sure there's much you can do except to flush it out with a garden hose in EACH direction. I got some brass garden hose fittings and just hooked up the hose, turned on the water and let it run for 20 mins or so. Then reverse the hose's and do it again.
It is a real PITA if you have to remove the heater core. Hopefully flushing it will do the trick.

 

[Bruce100]

thanks! You didn't worry about overpressuring?

 

[Gliderman8]

Honestly, I didn't... Maybe you should wait until others give you their thoughts regarding pressure.

 

[mrv8q]

Flushed both my 3 and 6 heater cores with hose pressure. Radiator shop wouldn't touch either core. Not that they're all that hot, but no problems.

 

[trrdster2000]

Bruce100, If you have to replace it, I have a couple and will check them out for you. I'm just up the road in Salisbury, give me a PM if I can help.

Wayne

 

[Bruce100]

Will do thanks Wayne

 

[Deleted member 8987]

I have used a standard garden hose with trigger spray nozzle for......50 years? on all types of heater cores, never, as in ever, had any type of overpressure issues. Of course, I did not make a hard connection, rather just held the nozzle up, pulled the trigger, same on other side, back and forth until clear.
Did you say the core pipes were plugged? Gave you probed to the end of the pipes (without hitting the tubes) to make sure some plug isn't in there?
Dave

 

[glemon]

I had the same problem on my 4a many years ago, I blew it out with some reverse pressure compressed air. Didn't need to take it out think I put a large cup and some towels in there. Wad of rust colored goop came out worked fine after.

 

[Brosky]

Just be careful. I have very high water pressure at my house and these units were only designed to work with a 16 lb max pressure in the system. And that was when they were new, not 40 plus years old. You don't want to accidentally split any seams.

And if you want to know what they really look like, you can see one here: https://www.74tr6.com/heater.htm