I have a 98 Grand Prix and about 2 months ago I was told that it has a transmission leak. I have kept an eye on the fluid level and have not had to add any. Up until recently, I did not observe any transmission fluid on the the ground. I checked the level again today and it was still fine but, I looked underneath the car and it was dripping on the ground. (red, no smell) Why, if I can see it leaking, is the level not going down?
Checking transmission fluid isn’t as simple as popping the hood and looking at the dipstick. Often, the engine needs to be running and already driven for 20-odd minutes. It will always appear high if you simply look at it first thing in the morning. Consult your owner’s manual for the exact procedure to check the fluid when hot.
Could you tell where the leak was coming from? A trans cooler line, perhaps?
In addition to what Budd wrote, there is a lot of fluid in a transmission so it takes quite a bit of leaked fluid to register on the stick.