Of course it reduces pressure. It's a "flowing" "dynamic" system. It's exactly equivalent to an electrical resistor, the voltage/pressure is reduced on the far side of the resistor/restriction, but only when current/coolant is flowing.
So please educate me. Until then, I say a restriction or a resistor will drop pressure / voltage in a flowing system (fluid flow, or electron flow.)
I appreciate the input from all sides, not trying to make any points of contention here. Just sharing my adventures with this latest repair - knowledge is power, and we all have our own unique perspectives. How about we all chill out a little bit? The last time I did this job, I'd just gotten the vehicle back from the body shop (was there ~ 18 months), and prior to driving it there (~200 miles from my home), I'd made the mistake of not changing the coolant frequently enough. The water pump went first, then the heater core, then the radiator. I'd estimate the coolant at that time was at least 3 years old without being flushed or replenished. This time, I'd been changing coolant every other year, but I may have stretched it longer than advised this last time, and my radiator began to leak at the tank seam. I swapped it out with a new Aluminum unit, as I chronicled here: http://v8buick.com/index.php?thread...-failing-al-upgrade-time.361105/#post-3105751 Put it in, drove it for a couple weeks, then enter the bathroom faucet under my dashboard at 70 MPH down the freeway. In any case, the new unit is now installed, and I've got my car back on the road. Just took it for a jaunt around the block, heater works, engine stays at good temp & no more bathroom faucet under the dash. I plan to do some more diagnostic tests on the engine to check for any further issues, but for now I've got a functioning cooling system again.
Plain ol' ordinary "green" antifreeze is advertised as having a service-life of two years. In fact, it will go considerably longer than that in most cases. Your leaks are NOT from "old" coolant. Your leaks MIGHT be from poor grounds, (radiator voltage) or a defective pressure cap, or some undiscovered problem. Don't mistake "closed" for "static". It IS a "closed" system, but it is not "static" because of the water pump which drives coolant circulation. This seems to be the root of your error. The radiator cap puts pressure on the entire system (except, of course, for the overflow hose and reservoir). The water pump puts pressure on part of the system, and "suction" on part. Restrictions in a FLOWING SYSTEM cause pressure drop, just as resistors in an electrical circuit cause voltage drop when current flows. Restrictions don't cause pressure drop when there's no coolant flow, just as resistors don't drop voltage when there's no current flow. But that's a static system, not the dynamic system. Consider also a power-steering system--"closed", but not "static". The PS supply hose to the steering gear--functionally the "restriction"--is a high-pressure, expensive, crimped-to-metal ends hose. After the restriction, the PS return hose is a low pressure, hose-clamp deal. The restriction lowered the pressure "down stream", so a cheap, low-pressure hose is sufficient. Consider an A/C system. Again, "closed" by not "static". The compressor raises the pressure of the refrigerant, the orifice tube or expansion valve is a restriction, which lowers the pressure of the refrigerant entering the evaporator. The A/C can't function if the refrigerant pressure isn't lowered by a restriction. When the compressor is disengaged, system pressure equalizes and then there's no more refrigerant flow. Consider a carburetor venturi. Air flowing past the venturi (restriction) loses enough pressure to "suck" fuel from the float bowl. This isn't a closed system, but it proves the point: "Flow" going through a restriction, loses pressure.
You're still incorrect. The water pump is a circulating pump within a closed system. It generates little if any pressure at all as it only feeds itself in a loop. This is obvious in practice as you can easily collapse the hoses with your hand, nor do the hoses swell with more rpm... Further the slightest amount of gunk will stop flow to the heater core or rad. You can label it anyway you want but you can't negate physics. You are only reducing volume, not pressure! You're point is moot anyway since Buick didn't use any kind of restriction in the heater hose.
