automatic transmission fluid - how much to top up?

[Gimli]

My 850 20V started over-revving recently. At first I mistook it for wheel spin but that seemed unlikely on a few occasions, so I checked the automatic transmission fluid level this morning. It showed nothing, perhaps a drop, when cold. On reaching work, the dip-stick was oily, but drying it off and re-reading I couldn't see anything. So I'm pretty sure it needs a top up!

The question is how much, as I don't want to overfill it either and don't know how to judge it without running the car.

The car is regularly serviced, but has just had a good long caravan towing session.

[iGGy]

Normal procedure, someone correct me if I'm wrong, is to get the engine nicely up to working temperature and the gearbox also, in other words, just after you've come back from a run and then with the engine idling, check the level with reference to the Hot line.

There's a fair amount of fluid in the box, so if you're not seeing anything on the dipstick at all, adding 0.75L at a time I doubt will cause you to suddenly be in an over filled state. Shift the box through the gears and pause a few second in each, then back into P and allow to idle a couple of minutes before checking the level again.

[Gimli]

I put half a litre in the Volvo (and about 1/4 litre on the floor, due to the awkwardness of getting the oil bottle correctly positioned!!!). She seems to be pulling OK now with no slippage evident.

Cheers,