Hi my daughter got a Ford S Max 1.8 tdci 2007. When I accelerate even slowly the car goes one way and I have to steer the other way. Then when I take my foot off it pulls the other way so have to steer the other way as well. Have put new rear trailing arm bushes on and new front wish bone arms then had 4 wheel tracking done. 

Was in garage for week and half but they couldn't find anything no play in anything. Sometimes when it does it the anti skid light comes on 

Have you used FORScan to check any DTC's ?

Was in garage for over week checking for any bushes gone or play in anything. Changed rear main bushes and front wish bones still the same. Garage doesn't think it anything to do with sensors in the steering

4 minutes ago, Lloyd69 said:

Garage doesn't think it anything to do with sensors in the steering

So I read that as the 'the garage doesn't know what the issue is'. Therefore I'd use FORScan and check for Ford specific codes which could well explain the behavior.

I was going up a hill in straight line and the faster I went the more I had to turn wheel opposite way to the wheels.

Sorted out problem. On The drivers side control arm one of the bushes was slightly worn. Put new arm on but while doing this the strut would not go back, one of the bearings had moved, when I took shaft out the grease was more like watery oil and just run out. Cleaned it up and put new grease in strut went straight back on. After everything was finished the wander was gone