Just fitted a new drive belt and the brake does not now work?

Have just fitted a new drive belt. I thought I routed it as before but cannot find any routing diagrames in my owners manual. I have excellent drive now (before I could onlly operate in low gears but now it takes off in 6th!!!!) The downside is that the brake pedal does not seem to have any effect. Before the braking was excellent. Can anybody help???