Ford has changed the dimensions on the slave cylinder for the 2000 Contour. However, they did not change the part number.
I found out the hard way. I installed a new one last week. Motor started fine but when I but it into 1st it did not move. I pulled the motor a second time and took the motor and trans to George Alderman (long time Caterham dealer) and the review began and George took measurements.
The new part measures .25 inches wider when compressed than to the slave cylinder we have been using in our Zetec for 12 year and have replaced it 4 or 5 times. The travel of the older slave cylinder was .24 inches. The new part measures .25 inched wider when compressed than to the slave cylinder we have been using in our Zetec. The travel of the older slave cylinder requires .24 inches to depress the pressure plate. With the new slave cylinder it simply never releases the pressure plate.
Lucky for me, George had a spare of the older design measurements and my car drives just fine now.
I think this new measurement is a stronger slave cylinder that was used in the 2.5 ltr v6s.
If you need a slave cylinder, check out Summit Racing. They have both a 2ltr and a 2.5 ltr slave cylinder for under $60. The photo for the 2.0 looks like mine and the 2.5 looks like what Ford sent to me.