530d Auto Trans-No Braking

[davidvh2]

I have a 2000 530d Touring wagon which has done 135,000 Kms. I bought it used (Factory owned car) & shortly after buying it, had the Tiptronic transmission overhauled to correct a problem. Now some 20,000 Kms later I have the same problem.

Gears change up perfectly & also down perfectly when a lower gear is needed but when going downhill with no throttle, whilst it sometimes changes down (& the rev counter rises as one would expect) it very soon changes into what feels like neutral & the revs drop off to near idle & the road speed will increase. In other words, I'm totally dependent on the brakes as I'm getting no engine braking. Attempts to change the gears down manually has no effect although if slow enough, one can engage 1st. Living in an area with lots of long hills, this is not nice at all. Any suggestions will be most welcome. Incidentally, I'm assured the box is a GM box & not the (some say) more favourable ZF box. Thanks in advance. Dave