How do you bleed the cooling system?
 

Hey, getting ready to do a cooling system flush per the instructions Cheezit posted a while back, which say "refer to Cooling System Draining, Filling and Bleeding in this section." I think I can figure out the drain and fill but how do you bleed the system? thanks

I've never had to or even heard of bleeding the cooling system on my truck. Drain, flush, and fill is all I've ever had to do and never ever had a problem. The degas bottle should take care of the bubbles that come out. Fill to the prescribed level, run it for a day or two and top it off.

OK thanks. The instructions also say to "Backflush the heater core. For additional information, refer to Heater Core backflushing in this section." Do I just disconnect the heater out hose and run some water through it for a while? Or is this also not necessary?

Never done that, but I think that would be a good idea. Dang sure couldn't hurt anything. Just make sure your heater valve (if you have one) is open before you give yourself a backflush bath--LOL.

Are you using the VC-9 cleaner??

I'm of the opinion that any kind of trash that you can get out of the system BEFORE you put your cleaning chemicals in greatly increases the effectiveness of the flush. I'm also of the opinion that using tap water to do the flush with is completely satisfactory unless you have "bad" water to start with. I do, however, use at least 12 gallons of distilled water AFTER the tap water completely cleans the flush.

Thanks again, NPC. Yes, I'm going to run the VC-9 through it for an hour, then repeat with a quart of Simple Green (I have no oil in the system, but figured it will clean out things even more), then flush til water is clean and clear.

BTW, when I do the final fill, I assume the system holds 28 quarts, so can I just add 14 quarts of Gold coolant and then top off with distilled water?

I"m not sure on the order of that. Maybe the simple green first????? I thought that the VC-9 also chemically prepped the cooling system surfaces???

I'm just following Cheezit's advice in this post here.

Ford does say to bleed the system. They even have a special tool to do so - pulling a vacuum I believe. I have always ignored it though.

Cheezit's the man

Interesting. I wonder if that's because of cavities in the block that might hold air pockets.

OK, thanks guys. What about my refill idea? Or should I mix the coolant 50/50 then add?

If you're going to go back and drain the block AFTER you flush you can, but when you just drop the lower hose or drain the radiator normally it will leave 3.5 gallons of water in the block and cooling system. If you fill with 3.5 gallons of 100% coolant after your last dose of distilled water it will give you a 50/50 mix.

I'm pulling the LH block plug, but once I'm done with flushing whatever is in there will be distilled water. I just wanted to be sure the system really holes 28 quarts, and from what you're saying it does.

I'm pulling t-stat now (fighting CAC tube...think I'll take it off!). I'll let you know how it goes. Thanks again!!!!

I only pulled the air cleaner for access.

Not meaning to hijack but I am interested in this as well. I too am getting ready to do a flush and would like to know if anyone has the procedure for bleeding the ststem and is this "special tool" necessary? I don't trust the local dealers to do my work. Pretty sure they would half-a$$ it and also use tap water. Any help is appreciated!!