I’m replacing my therm tower on my 2003 VDP along with hoses, knock sensors and anything else I gain access to when the intake manifold is off. It just struck me though.....why is there a cap on top of the therm tower? Do I need to do something with it when/after putting in the new tower?

jeff

 

It is for fill/bleed air from system. (highest point in the cooling system)

 

Thanks. I've always added fluid to the reservoir. This makes more sense.....