Engine Coolant HeaterValve

It seems that the engineered DesignLifeTime for this vehicle, assembled in 2000, was\is about 18 years;
starting in 2019, during every Coolant system maintenance task (ThermoStat Valve, Hoses, Flush+Fill,...)
yet another factory plastic part (ThermoStat Housing, HoseTeeFitting, RadiatorSideTank...) cracked+leaked. In
2020July, on installing new hoses in & out of the HeaterValve, it cracked & leaked. Like the ThermoStat Housing
& Radiator, the Plastic Valve was replaced with the AllMetal Valve below, common on 1970s+1980s vehicles.

Links To Related Info

Thanks go to the brave souls who've preceded me in similar adventures & freely shared their experience:

https://web.archive.org/web/20210426172839if_/https://www.ranger-forums.com/2-9l-3-0l-v6-tech-32/new-me-ranger-blows-up-heater-hose-165200 Coolant HeaterValve Failed

http://youtu.be/CZPJcSqaa08?t=95 Coolant HeaterValve Repair

http://youtu.be/GBSrBGha1w4?t=36 Coolant HeaterValve Repair

https://web.archive.org/web/20210523083714if_/https://www.motorcraft.com/content/dam/ford-motorcraft/en_us/motorcraft_global/products/lubricants/quick_reference_charts/antifreeze_coolants_english.pdf Coolant FluidSpec

https://web.archive.org/web/20210629012517if_/https://www.kostusa.com/page/antifreeze-coolants Coolant MixTempRanges

http://web.archive.org/web/20200920100659if_/https://www.explorerforum.com/forums/threads/stop-leak-coolant-additive-which-one.489558 Coolant LeakPrevention With KSeal