I am trying to flush out my coolant myself because I have that muddy, sludge looking coolant and to be honest, do not know when it has been changed and cleaned. I feel I have read almost every thread on this forum to do with the topic. I took out the coolant reservoir, and am cleaning that. I am trying to drain the fluid out and I have the original looking drain plug (one that you can fit a 1/4 ratchet in) I have tried turning it but it only turns maybe 10% ccw and won't go anymore......does it need to pop out or should it just screw out? I know a lot of people say to just pull the hose off that's right above it, there's a plug right underneath the hose and I know fluid is probably fine on it but just wanted to avoid dumping several liters on it. Any ideas? Thanks.


Also, it's on a 2001 blazer.

 

If you are talking about the petcock valve, it will only turn a quarter of the way. It can be a major PITA to turn so be careful not to break it as it is made of plastic.

I don't know of any "plug" though so I don't really know what you are talking about.

 

Yes, it's the petcock valve then, I thought it was called a drain plug, sorry. Got it turned probably that much or close to it but will not drain. I just didn't know if it just automatically drained once you get to that point or you had to pull it out. Since I was googling radiator drain plug, I'll search for petcock and see if I can find additional pics or videos on it.

 

When I do coolant flushes I pull the lower rad hose to drain the system.

 

hole may be -plugged , stick a nail or something small in it

 

If you're flushing the cooling system you definitely want to pull the lower radiator hose to get a good flush. You don't want to rely on just the petcock to drain the radiator for flushing purposes. It's impossible to get all the gunk out of the radiator through the petcock. Flush out through the lower radiator hose outlet.

 

Sure would be nice if the petcock would at least drain down so you could catch the antifreeze in a bucket. Once I do get the petcock open it just runs out on the frame and goes everywhere and pulling the lower hose off makes just as big a mess.

 

Well I was hoping the petcock valve would have helped me drain the coolant without much mess, but ended up pulling the lower radiator hose. Worked but was a mess. I saved one thread where captain hook listed step by step on flushing the coolant so I'm gonna start on that. But I'm still gonna try and figure out the petcock valve, make sure it's not broken and I'll post how everything goes.

 

I have not seen anyone advise the fellow that turned the petcock 1/4 turn and got no drain that he needs to turn that 1/4 back the way it was or it might later POP out like it is supposed to and drain the coolant going down the road.

I was searching for an easy way to get that open also, no luck but I had already taken the bottom hose off hoping to get a better grip on it and think now that it is safer to go with just the bottom hole rather than break that sorry excuse for a drain petcock.

 

List this thread please.

George