High milage diesel c5 10100 miles ex company car bought this car 3 months ago, when purchased it had stood for 3 months ( in manchester ) after running for about 500 miles i started getting a squeak from the rear, mechanic friend had a look and there seemed to be a lot of dry joints, treated with spray grease, this eased this problem , then started getting a metalic knock not all the time but when going over a bump it was if there was so movement and a metal part was hitting metal no sign of anything, so kept an eye on it. Yesterday had another look on and decieded to remove the rear wheels for an inspection around the discs, had the car set at full height and engine on tickover, after about 5 mins we saw what can only be described as smoke or steam coming from under the hood and around the offside wing, the wing was hot as was the hydralic resovouir, engine off remove cover and look in resovoir, it's empty, got a gallon of fluid and it took about 1/2 of it, when pressing the raise/lower button the front which had already lowered stayed put at normal height, but the rear stayed in the air. there are and have been no signs of leaking fluid at any time, so where has it gone also is there anything to be done ie; bleeding to lowe the rear, i just hope the pump is not burnt out, any ideas please