For openers, I have spent 2 days scouring these forums (and the internet in general) trying to get a handle on this.

It is one of the most frustrating things I've ever tried to do mechanically, and I'm a guy who fished a broken-off starter mounting bolt out of its hole once.

Okay, so the drain plug/petcock, whatever is at the bottom of the rad on the passenger-side. I peeled away the skirting in the wheel well so I could get at it, but the tiny little gap I have to work through isn't large enough to see anything or get a tool into.

I did see a sort of a white plastic wingnut-like thing attached to a T-fitting that ends in a down tube, so I figure that must be the petcock, right?

(There is maybe a pic in this thread, but it looks like the link has gone bad because all I see is the img tags with code in them, no pic.
https://blazerforum.com/forum/2nd-ge...in-plug-15571/)

I managed to get a small adjustable crescent wrench in there with the jaws narrowed enough to grip the tab on the plastic petcock and got it moved a quarter turn and exactly nothing happened, nary a drip - not even after I removed the rad cap.

Then I managed to break off half the plastic tab while trying to shut it.


This makes me think it must be plugged, so I started looking at how to get the lower rad hose off.

It looks like I have to remove the battery and probably the mounting plate the battery sits on and also the metal tube that I suppose is the rad cap blow-off line.

After all that is done, how is the rad going to drain when the lower rad hose enters the rad a third of the way up. How does the lower third of the rad drain?

Am I stupid? Or am I just too frustrated by this to think clearly?

Is there any chance I might have success draining the rad with a siphon?

I can feel a vein throbbing over my right eye.

 

That info IS in this forum somewhere,I've seen it. But I believe the petcock needs to turn a full 1/2 turn to drain. One can reach it with a long pair of needle nose. Yes the plastic may be brittle and will break. One does not need to remove the battery or tray to access the lower rad hose,altough I suppose it would make it easier...
You must get the petcock open as you saw that 25-30% of the rad may contain a lot of sludge you want to remove. Good Luck!

 

its a poor set up. the factory one takes a 1/4 inch square drive, use a short extension and a wobble from the wheel well. it only turns a quarter turn. when it turns in backs itself out quickly, alota time its sticky, so try to turn while getting behind it with a flathead and helping it out. u can by new ones at auto parts for a few bucks. to get as much as u can get the drain open and jack up the back of truck as high as u can get and let drain for at least a half hour.

 

I guess it must not be a factory setup then.

This has a white plastic tab that I can't get a tool on and I can't move it with the tips of my fingers and to get at the other side of it, I'd have to take off the front skidplate and the lower fan shroud.

This is ridiculous. How much would a garage charge for this job?

 

I never screw around with those drain valves on any vehicle. Takes way too long to get the coolant out. I just disconnect the lower hose. Bam - drained in less than 30 seconds.

 

When I did my water pump, I did the same, just pulled the lower hose and drained it.

 

When i drained my fluid i just reached down from the top with needle nose pliers and turned the petcock until fluid started to come out the drain hose, i have long arms so it was really easy. so i guess my question is did you try to get to it from the top? i suppose you could just take the hose off but that might be kind of a mess.

 

I finally got the petcock open when I figured out that I not only had to turn it , but pull it out also.

I still have to put the skirting inside the wheel well back and bolt the skidplate back on.

Between that and changing out the summer thermostat for a winter one, the freakin' job took me 3 days.