I have a conundrum hopefully you guys can help before I got to auto zone and spend like crazy. I have a 92 Bravada 4.3 non vortec.

Issue one, I have this brown crap in my radiator. My buddy and I flushed it completely out... As best we could. Open plug drain run hose then run with fresh water. The water came out clear. Then a week later I was snooping around in there and noticed that the crap was back in force. Maybe some one knows what it is and why its there?

Issue two, Its almost winter and we need heat. There is vary little heat coming from the vents. The defroster kinda gets warm and works if left for a while. So defrost blows sorta. Down by your feet blows some what and if the A/C is on you can feel it there. But there is NO air coming through the normal front facing vents. And seriously there should be hot air coming out. The truck was getting super hot because of a leak, and that did not change the temp of the air at all.

So whats the problem? I'm guessing this is all normal for this rig because i have heard of these issues before. Also it is a good running rig besides some squeaking under the hood that drives me nuts!

I plan to fix the heater core, Thermostat and Belt today. Hopefully some one can shed some light on this thanks guys

 

ok good start with the thermostat. is the heater core leaking? why are you gonna replace it? (you can just pull the hoses from the firewall, and flush it seperately.

you should pull the drain plugs on the lower parts of the block when you flush it.

 

OK here is the update. The PO apparently thought that the truck was running hot. Because they did not have a Thermostat in there at all. Which makes sence because the freeze plug is leaking (next adventure). So after a huge battle with the Heat/AC control box I managed to loose the cable retaining washer and found 4 small springs I have no idea where or to what they go.

Truck is heating nicely now but for some reason no air will come out the forward vents. I do not get why that will not work. but at least there is warm air. checking that off my list now.

So what would cause the vents to not get air. My friend thinks that there is a missing vacuum tube that feeds to that vent. Note that there did seem to be a place for another vacuum tube. But no where to be found was a tube that may have been there? Not sure on that. anyone ever pull one of those things completely off?

 

I had the same problem with my Blazer, the air was not being deverted to the vents. It turned out to be the vacum solenoid that opens and closes the flaps to devert the air from vents to floor etc. Check your hoses and the solenoid with a vacum tester

 

what colour are all the vacuum hoses that run to the enviro switch?

 

Here's what they should be for a '92:

 

ahhhh. thanks to the Master of the Schematics for the info. how big is that file you keep them all in Kyle?