can i repair a coolant leak from timimng cover without replacing the gasket.

It would be useless to do so! .. Mechanical repair is the only reliable fix! .. Replace failed part(s) .. I've been working on vehicles for on to 44 years now and I have tried ALL of the quick fixes, they simply just don't work, not for long anyway... Next thing ya know, you're sitting on the side of the road in the middle of nowhere, broke down because that junk has let go and problem has returned... My 'old school' advice is 'fix it right' to start with!