Thanks for getting back. The fluid is OK now. Have just bought this vehicle and it drove a good 100 miles home. The following day just couldn't get reverse. Discovered transmission fluid on ground, topped it up and got reverse OK. However when it was being checked at the garage they recommended replacing power steering pipe as it was corroded. This was done and I mentioned to them that I had difficulty reversing. They suggested having the gear box refurbished at a cost of over £1000. As you can imagine I was sick as a pig. Then I joined this club, you answered and I've had no more trouble EXCEPT when I reversed after a 30 mile trip and had a problem, if I shifted to neutral then reverse it worked perfectly. How do you like that?!?! By the way have checked for leak and can find none.
