you introduced a new term, header tank, do you mean the expansion tank as referred to in the guide you posted? When the old coolant starts to come out, you might need to readjust the position of the drip tray to avoid spillages. Rust and dirty coolant that circulates in your car’s cooling system can lead to a clogged radiator, resulting in overheating and engine damage. Use the flush solution: Now you have an empty radiator, you can begin flushing your car radiator system to ensure that it is completely clean before you add fresh fluid. Because I did that job on an Audi S4, I had the extra "bonus" of needing to fabricate a "coolant level raiser" to temporarily raise the coolant level in the reservoir up beyond the supercharger heat exchangers and the cabin heater pipes!

com/cooling-heating-and-climate-control/radiator-flush-tools/p/peak-flush-and-fill-kit/525931_0_0" on this server.By the way, the test strips ended up getting too old to be trusted but I could see a change in the PH value which indicates that the coolant is degrading from being slightly alkaline towards being acidic and when that happens the corrosion protection has dropped.

Ideally all these newer engines need the coolant system to be vac'd down by coolant refill vacuum kit, then that kit is used to reflood the system, I've just done that job on my 2011 S4, it all went very well except for getting the "quick release/quick fit" to lock correctly first or even 10th time, very annoying!I too wouldn't want to bet my engines on a plastic fitting but conceptually the ability to connect running water to flush the system versus the current method of draining fluid, filling with water, running, draining, wash-rinse-repeat until the system is clean is a better solution. Cleaning out the old coolant and blasting away at the system with water from the garden hose paves the way for new, uncontaminated coolant to do its job.