There is only window washer solvent container - it feeds both front and rear.
should be the same reservoir as the front windshield wipers
Both washers work from the same tank under the hood.
It is the same reservoir as the front window washer.
It is the same as the front winshield , at least on the 2001 holds about a gallon
On a 2002 Mercury Mountaineer : ( DOT 3 brake fluid meeting Ford specification ESA-M6C25-A ) According to the Owner Guide
Mounted on the bottom of the washer fluid reservoir.
If this is a 4 door , the rear washer is supplied by the engine compartment washer tank on a 2002 Explorer ( if 2 door , open your liftgate and above your left tail light there is a fill plug - remove the plastic panel to your tire jack storage and you will see the washer tank and its fluid level )
According to the 2002 Ford Explorer Owner Guide the washer fluid for the rear liftgate is supplied by the same washer fluid reservoir as the windshield ( located in your engine compartment )
There is no transmission dip stick for a 2002 mercury mountaineer, fluid will need to be checked from under the vehicle. There is a fill plug on the transmission, remove the plug and fluid level should be up to the level of the plug hole. This is the only year mercury did this in the mountaineer.
Follow the hoses from the washer outlet spray heads backward to the washer reservoir.
Down the tube that holds the trans dipstick.