Bob_T442

My 'Stang hit 6 years in July, and though I'm a little tardy, it's coolant change time.

The service 'manual' (CD disc) states that I'll only be able to drain up to 80% of the 12-quart capacity (obtained from specs page in owner's manual) from the cooling system through the radiator petcock.

Upon loosening, and eventually completely removing the petcock from the radiator - with the cap on the 'degas' bottle removed - only about 2 quarts drains from a previously full system.

Does anybody have any tricks up their sleeves to drain the rest of the coolant from my Cyclone V6? Are there drain plugs in the side of the block (or front or rear) like I have on my '85 Olds V8?

I didn't think this issue would rear it's ugly head, but what gives? I didn't see any related posts in the forums.

Thanks in advance

cbdallas

I did a coolant change on my '05 Sport Trac in 2012. Instead of pulling freeze plugs & going through all that labor, I just drained the radiator, disconnected the top hose from the radiator, then stuck the end of the garden hose in the radiator and let the water run while the engine idled. Kept that going until clear water ran out the top hose, then let it run dry. Changed the hoses, belts, thermostat & radiator cap while I was at it. Re-connected everything and re-filled with a 60/40 mix of coolant and distilled water. The 4.0 didn't need burped, but yours might.

Derf00

Similar to what CBDallas said only instead of a garden hose, use compressed air in the hose at 15-18 PSI.

Unless you flush thoroughly with distilled water at the end or with your mix of coolant/water before actually filling your system.

The only reason I suggest that vs a garden hose is that the water from the hose will be hard water with potentially lost of minerals or even sulfur (well water). Sulfur can combine with Hydrogen from the water under heat and degradation over time to create Hydrogen Sulfide (H2S) which is very acidic and can corrode the cooling system over time.. Even if you don't have Sulfur, other minerals will increase the electro-conductivity potential of your cooling system. That is ability for the cooling system to conduct electricity. That leads to electrolysis which eats your cooling system from the inside out.

That's why it's recommended to use distilled water for cooling systems. No minerals, not conductive to electricity, and has a neutral PH.

Urambo Tauro

+1 on distilled water. Don't use tap water unless you're going to be flushing it multiple times. And even then, your last couple of rinse cycles should be distilled. For final fill, add half of the overall system capacity's worth of straight undiluted coolant to whatever water has remained behind. Then use distilled water again for final top-off.