When I flush it with the hose the vents blow hot air like new. So this points to something contaminating the core after the flush, yeah?

 

No, you're good with that. The water has someplace to go so there's minimal pressure buildup. I had the core in my hand, plugged one end, fastened hose to the other not even thinking about the mechanics of it. In other words, I really KNEW better.. I was forty something then, so senility hadnt set in yet..

Someone on the Mustang NG told me later the core mfrs began warning not to do that so I apparently wasnt the only one.

 

Oh! oops, live and learn right? I've made my share of mistakes too.

I guess the next step is to order a new rad. I'll flush the system again immediately change the radiator. Hopefully this works!

By the way, I really appreciate all of you being so kind and friendly to a newcomer such as myself.

 

Perhaps...perhaps not. I had a situation once where the heater worked fine using the T adapter but when I removed the T air would go into the core and wouldn't let the water through. Burping didn't seem to help but when I was on a trip a few days later it magically cleared and I had heat. Many of here have used the garden hose connected directly to the heater core. Using the T with the radiator cap usually will not clear a clogged core as the water will take the path of least resistance, bypass the core and go out the radiator. You just have to be careful to not have over 50lbs of pressure so you don't blow the core.

 

Hmm, path of least resistance, that makes excellent sense. since the heater hose is cut I just remove the t inlet and run the garden hose yeah? Don't even have to remove the radiator cap. One question, should I put the garden hose with the water streaming into the firewall or the other way around? I think away from firewall would be best so the water doesn't clog the rest if the system in the way out.

 

Disconnect both hoses from the heater core. You'll notice that one is bigger than the other so depending on your garden hose ID you may have to jury rig an adapter. I have an in-line valve I use to control the hose at the car. Connect one hose to the inlet and hang it outside the car into a bucket. Connect the garden hose to the core outlet with a clamp and turn on the water. If the core is clogged nothing or very little will come out of the other hose. Sometimes I've had to alternate the hoses back and forth a few times to clear the clogs. Just make sure your house water isn't over about 50lbs of pressure and you shouldn't have to worry about blowing the core unless it's already corroded and almost ready to blow on it's own.

 

Well, here's the news. Flushed it again, heat works, temp gauge won't even budge from its initial resting point, there is a pinhole leak in the metal housing that connects to the thermostat, and when I ran the truck with the rad cap open a "foam" came out if the radiator. Blown head?

 

Foam generally equals air, let it run for a while with the cap half on... the system may still need burped.

Unless the foam is brownish, then it sounds like the head

 

Did you put the thermostat back in after flushing? Did you have gauge problems before or is it new. I'll agree with running without the cap to burp but more for the gauge as there could be an air pocket causing the sensor not to read properly. The water outlet pipe that's leaking is common...thin metal instead of casting..costs about $20. I had to replace mine a couple of years ago. Did you put coolant in or just water? I usually don't see foam after a flush unless there's another problem. The leaking water outlet could be sucking in air or like you fear..head gasket. The combustion test I mentioned in a previous message would let you know...blue test fluid no leak..yellow = combustion leaking into coolant. If you do have a head leak there's a fix in a bottle I saw in a video but I have never tried it nor has anyone I know...perhaps someone here can comment on it...Blue Devil.

 

Will do a combustion test asap. Apparently the thermostat is a fail safe you're which locks fully open if the vehicle overheats even once. Which explains the temp gauge. (duh)