Bongo Fury

I have had an ongoing problem with my automatic gearbox for a while.
The problem was that it would not change gears when engine was cold, so i had to run it standing still for fifteen minutes then it seemed to change gears ok. The problem seemed to right itself, but the hold light keeps flashing. So just when i was thanking the lord for putting it right,it
has started again with the original problem. I had a word with a guy who knows a bit about gears and he said it could be a valve block in the gearbox. As i am clueless about these things i was wondering if anyone
knew what this was and what it does, and can anybody shed any light
on the flashing hold light as i suspect the two things will be connected.
Any help would be greatly appreciated as it is doing my head in.

Have you checked the flashing squence against the fact sheet in the members area?

For starters new fluid and filter in the box and if you have a speedo convertor chip then try diconnecting it. They often give trouble.

You're on the ball as usual smarty - kevo was advised about changing the fluid and cleaning the filter the last time he posted - hopefully he took heed of the advice...............

Thanks again everybody,i will let you know how i get on.