Yes, firstly, check the oil level in the gear box and top up as necessary (there is a procedure for this, be sure to do it correctly. Most mechanics are unfamiliar with the procedure for older auto boxes so be sure you trust them if you use one) .
An auto box stop slip/ conditioner will help to clean all the pressure valves, I use the lucas one.
Look at this on eBay
http://www.ebay.co.uk/itm/321803638603As for what you can do while driving, if you want it to kick down there is a button on the floor under the accelerator pedal. You need to push the pedal all the way down to the floor and then a hard press to push the button down as its on quite a hard spring.
I found this annoying at times so affixed an extra switch to the gear selector so I can operate it by hand.
If I can find the original Ford hand book I'll post a picture of the relevant information
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