Heater core and anti freeze question

[badmix]

I just changed my heater hoses, they had been on there since I bought the truck, not sure why I didnt change them b4. but anyways. I was able to change them without making too big a mess. But here is my question or a few of them at that.

1) Does coolant go thru the heater core even when the heat is turned off, does it cycle constantly thru the core?

2) When I pulled the hose off the core, it came out copper looking, but the coolant in the radiator was greenish. Why would this be?

3) I pulled the hose off each end and held it up so I wouldnt make a mess, when I tipped the hose into my pan, it had copper flakes come out of the hose, why?

The heater core is about 2-3 years old. The truck is 84 K5.

When I get the time, I plan to do a coolant flush some time. I dont have any coolant issues, temp runs 190 all the time, no matter the heat outside or the a/c running. I run a 50/50 mix here.

ANyways. I was just curious. thought id ask.

 

[4X4HIGH]

Coolant flows through the heater core regardless of the heater being on or not unless you have a heater control valve and to the best of my knowledge GM never used a control valve on our year rigs.

If you mean the coolant/water coming out of the hose looked copper looking it could be some rust/calcium deposits.

 

[4xcrazy]

Coolant flows through the heater core regardless of the heater being on or not unless you have a heater control valve and to the best of my knowledge GM never used a control valve on our year rigs.

If you mean the coolant/water coming out of the hose looked copper looking it could be some rust/calcium deposits.

funny that this comes up now and then, and also the fact that i had to take pictures of mine and post them up on here once before to prove that there are some trucks with these vacuum controlled heater control valves...

 

[smalltruckbigcid]

Some of the AC equipped trucks used the heater control valve to make it easier for the AC to operate in the heat without any competition from the heater core sucking up cold air. Most however didn't have that valve.

The other thing copper colored flakes could be is stop leak....

 

[dyeager535]

I'd second the stop leak stuff. I don't ever recommend that stuff, I've seen it stop up overflow tanks too, which causes coolant loss. Kind of defeats the purpose. Trail fix it's better than nothing I suppose.

 

[badmix]

Well, Ive flushed the coolant system in the past, replaced the heater core and hoses and now just did the heater hoses. I never used STOP LEAK, since ive had it. Not sure about PO though.

 

[dyeager535]

It seems to linger pretty good...if it plugged up in one big ball in the heater core or something, I can see it breaking apart at some inopportune time, or not coming apart in just one flush, etc.