Quote:
Originally Posted by bomelia
Ron,
Air comes out of the defroster (cold).
Paz, I will try that! More and more I am becoming convinced that it is an air flow control problem. I'm still going to blow water through the core in the opposite direction to be sure... but I still do not understand how it could flow one way and not the other.
Mike
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Mike,
Some of the rust flakes are larger than the holes in the core. These pile up, or gather, up against the small passages on the
in side and restrict water flow just as a clogged filter might do.
As in air filters, reversing the flow causes particles to easily "back out" and reopens the major flow. But, just like an air filter, where back-blowing it out with compressed air greatly improves flow ability, some scum and associated particles stick to an extent making core holes smaller in diameter. Usually performance is acceptable after the large flakes depart though.
The consumer power flush chemical is supposed to largely dissolve scum. In severe cases, a radiator shop can "boil" out a core with industrial grade chemicals that would be dangerous to use around the home. And then reseal the leaks that sometimes open with such aggressive treatment.
As an aside, more than you ever wanted to know...
Paper air filters can be repeatedly back-blown and reused nearly indefinately. The filter companies recommend against this and even promote the false idea that a fuel injected vehicle will use more gas because of imperfect flow. Not true. The vehicle may experience less top end power because of less possible total air, but fuel automatically corrects itself to available air.
The "fuel hog" idea lives on because it was commonly believed that a restricted air filter could easily cause a carburated engine to burn more gas. Also not true to a large extent. All common carburators have a tube called a balance tube that sees and merely transfers that same minor "air restricted" vacuum that accumulates above the venturi jets (to "suck" more fuel), also accumulates(transfers) above the fuel level in the float bowl to equally "suck" the fuel from the backside, thereby evening it out. Extreme air filter restriction can defeat this bit of self-regulated engineering. Extreme vacuum would first boil (vaporize) the float fuel, making the float fall down and then suck the gas directly from the gas tank, if the engine could run this long.
And then, there is the idea of back-blowing those in-line under-car fuel filters also. Works just fine and saves buying an expensive new fuel filter against manufacturers "bottom line" recommendation, of course.
I have found that the money saved can be applied to buying a six-pack of "human power flush" to keep plumbing intact. And make the job more enjoyable.
But don't fully flush until the job is successful.
In theory, any filter can be reused in full
Red Green philosophy. The one filter I don't recommend back blowing is the
oil filter. Don't ask me how I know that, other than I ran out of "flush" early on.
Wes
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