1999 BMW 318 4 cyl Two Wheel Drive Automatic 210000 miles
The transmission seems to have a small leak somewhere as there is reddish oil on the garage floor - a few drops per night only. This has been leaking for a few weeks now.
I have read forums etc and topping it up and checking levels seems to be a nightmare as it must be done via filler plugs etc.
However tonight I noticed a little plastic reservoir below the air filter which says ATF oil only. I unscrewed the lid and inside is red transmission fluid.
The plastic cap has an internal hollow rod attached with two markings on it. Presume fluid level must be bwteen these marks - it is a bit lower though.
Is this where I can top it up and must the temperature be between 30 and 50 Deg C to gauge the correct level.
Also what fluid is recommended