The leaking O-ring seal behind the timing belt cover however is a lot more difficult to replace. It takes approximately 10 hours to replace the 50 cent o-ring. The only differences between the MK3 and the MK3.5 1.0 ECOboost cooling system are the degas hose design (The MK3 can easily be converted to MK3.5 specs.) and the fact that the MK3.5 has .

ford focus 1.0 ecoboost timing belt change