Service TAx credit on vehile repair used for employees

Your question is not clear. I think you are talking about Cenvat credit on the payment of repair bills of vehicle used by your employees. If you are taking input service for providing output service then u can take the cenvat credit on payment of input service. Example: if such emp,oyees are sales man and providing door to door service to customers and use bikes or scotters to reach customer place, then u can take credit on repair bill. There may be like other situations. 

Generlly in What items Service Tax  Credit Taken?

The input services credit is available in 3 main segments

1) Used in relation to manufacture or clearance of goods or used for provding the output services

2) Used at the time of setting up modernisation expansions

3) Used for business

The last part in my view covers almost all genuine business related expenditure. The audit parties keep objecting and over years the Tribunals keep allowing the credit. Only specifically excluded / personal/ non business expenses where ST paid would not be available.