heater core tubes

[Weelan]

So the P.O. bypassed the heater core, and I've looked at it and I think he only bypassed because of issues with overheating. I had the engine rebuilt, and before I noticed a lot of build up that was blocking flow. I want to reconnect the heater core, I took pictures of it and I think the it'd be ok to maybe flush the core with a low pressure hose and clean it and check for leaks.

Does it look like it's ruined to anyone? I think they're fine.

[rlux4]

Usually a heater core is bypassed because of a leak. Either the core itself or the heater valve. To bypass it because of overheating would almost be counter-productive. An old trick to help while overheating is to open the heater and because the heater core is a small radiator some heat is dissipated by it.
Ron

[So Cal Mark]

you're virtually guaranteed a leak at the tube seals. Once the seals dry out from being bypassed, they need to be replaced

[Weelan]

Darn, I was hopefully. Glad I checked first. I'll work on pulling that stuff out. For now I might bypass it just to get the car running so I can enjoy it some. Although that's a lot of effort redoing the coolant, I'll see what I can find for where a leak is.

[wizard124]

From an earlier post of mine:

I dropped the heater core. There was some crud visible. Flushing with a garden hose removed a good bit of stuff, but i could see there was more residue. I needed to try something more. I ended up using "Simple Green/ Lime Scale remover". This comes in a spray bottle. CLR warns not to use on brass/aluminum...this product does not state this limitation. I figured it must be gentler and it has a different active ingredient. I used it straight out of the bottle and let it soak for 5 minutes, flushed and repeated a second time (used the entire contents). Some ugly blackish water/cleaner flushed out so it must have had some effect. No leaks so it is ready to go back in.

I my case the valve was frozen and completely plugged. But my core was leak free.

[Weelan]

Cool, good to know. I'll give that a shot. Thank you