Using cooling system leak fluid; how long should I wait for my engine to cool down?

(2010-05-30 09:38:05) 1. nickname Says: I'm using some sort of chemical that my mechanic gave me -- it's supposed to fix the leak in my radiator as opposed to replacing the entire thing. He told me, as did the directions on the bottle, that I have to put it in "cold." So I guess this means put the stuff in once the car's cooled off completely. How long should I wait? Three hours? It's, like, 90 degrees out right now, if it matters, and I just drove it for fifteen minutes.

Also, it says to start the car with the engine idling, THEN take the radiator cap off, and then add the stuff. Is this safe? To actually take the radiator cap off while the car is running?2. Keny P Says: So long as the engine is cool (I personally would wait two hours after driving if it reached normal operating temperature), opening the radiator cap is ok. BUT I would just open it before you start the car because there's really no point in opening it after the car has started. Some coolant may squirt out when you turn the car on but it's no big deal. Oh and just so you know, most of those radiator plugging chemicals don't really work all that well. IN fact they can sometimes plug up the wrong area and cause further damage. I find it strange your mechanic would tell you to use that stuff instead of just telling you to replace. I'm not saying that stuff won't work, but you shouldn't be all that surprised if your radiator still leaks or something worse down the road. Basically it's not really a long term fix3. beep beep Says: an hour or so is good, it will be cooled off enough by then...yep, you can take the radiator cap off with a cold engine.......i am guessing it is silver seal, or bars leak...bars leak will eventually plug up your heater core on your car.. Tag: Using cooling system leak fluid; how long should I wait for my engine to cool down?