Automatic Transmissions confuse me.
 

I've been working on changing my '85s ATF and filter for the better part of two months now (not working very hard mind you :rolleyes:) and have a question.

The owners manual states to check the ATF level with the engine idling in park, and that when the fluid is cold it should be a bit below the "low" mark. I added fluid to below the mark, drove the car a little, then let it sit for a few weeks.

Today I checked the fluid level again before I used the car (after letting the engine idle in park for a few minuets) and the fluid level was almost at the bottom of the stick. “Great....I must have a leak” I thought, so I added another half a quart of Mobil 1 ATF. After I got home from driving with everything nice and hot, and the engine running in park I checked the fluid level again and it is about 1/2" above the high mark.

What gives? What is the fluid volume between the low and high marks on the '85 transmission? Should I use hot fluid or cold as my bench mark?

Thank you.

Hot. But don't try to check the level for 5-10 minutes after the car has been driven. Then check it while idling in park after shifting through all gears.

OK. I drove the car until it was warm, parked it for 10 minuets, started it up and let it idle for a two minuets, ran it through the gears, put it back in park and checked the level. It was right at the full mark. Guess I am set. Thanks.

RTFM man it says hot and idle :)...

They confuse me to which is why I put a stick in!

Had a similar experience the first time I drained the torque converter. Refilling took much longer than I anticipated - add a bit, check, add a bit more, recheck. Half of it was I didn't know what to expect and thought I was doing it wrong.

i'm confused. whats the point of going though all the gears then parking for 10 mins. then going though all the gears again and imediately checking the level?