I decided to just make more a generic thread for help while I flush out the coolant.....well got the hoses off the heater core at the fire wall, one hose was so swollen that the hose clamp being all the way open still would not come off. I cut a few inches off the hose and peeled it off the heater core plastic hose. It looked like expanding foam underneath the hose and after wiping it off, there's a hole in the plastic.....so please tell me I do not have to replace the whole heater core. If so......i'll live anyways, ha. Here's a pic.

 

Out here finishing the rest of the flushing. Got any opinions of what my options are with the hole?

 

If this was me, I'd make sure the clamp on the firewall side of the hole. I'd try that before I replaced a heater core. Be sure to try to clean it up before placing new hoses on. I replaced mine a few months back and looked nothing like this.

 

Thanks. I called my father up and that's exactly what he said. Also, he said the yellow expanded foam looking stuff is probably some sealer stuff he put into the radiator about 9 years ago. The lower intake manifold gasket has been replaced since so it hasn't been leaking. So that's one mystery down lol.

 

So small update, drained the coolant, followed some instructions I found on here by captain hook going about flushing each component of the coolant system. Got all the brown sludge out as I could get and put it back together. Instead of tsp, I went and used a radiator cleaner I got from advanced auto. I had no leaks from the heater core hose where that hole was and the heat came on inside for the first time in months(this was a small victory but haven't won the war yet ). After running it a while the past couple days, I drained it again and it was less brown sludge but definitely not clear. I'm going to go back through and flush everything out again. I'm thinking of trying that tsp this time around. I also changed out the radiator cap and have a new thermostat ready to go in after the coolant system is cleaned.

So the blazer has almost 140k, water pump has never been replaced. While I'm in there, should I replace it? I'm leaning towards yes. Thoughts?

 

So I've flushed it around 5 or 6 times, started coming out clear but the inside of the hoses are still just nasty and coated with gunk, it comes out with a wipe or very light with a flat head, but you can only get so far inside. So any tips? Or if I want to 100% gone, i'll have to take out every hose and get a long brush or something. I've been using a strong mixture of tsp to clean with. Got a 4 hour drive this sunday and it's not supposed to be freezing so i'll just fill it with water and deal with it more next week. Here are some pics.

 

The entire cooling system is contaminated with that crud: Radiator, heater core, engine block, overflow reservoir, etc. You're on the right track for cleaning it out, and getting it all out will be difficult, probably requiring chemicals. As for the hoses, It might be easier just to replace them.

 

I am fighting the same issue right now. I ran about 6 gallons through this weekend and I still had brown sludge coming out. I finally put regular coolant back in just so it wouldn't freeze up.

 

Yeah....I'm paying for it now due to it never having a coolant flush in its 140k life. But I'm learning this car maintenance stuff:-) I saw some instructions you said in another coolant thread and I've been following it to a t. But there is just so much gunk in there but it's starting to come out clear, and no more brown. I usually run the car for 20-30 minutes with the tsp, any benefit running it longer?
Man, have fun, lol. That's one advantage I have with this blazer, it's not my daily driver so I don't have to rush to put it back together.