I have a 87 Coupe GT with 113,000 miles. I changed the timing belt about 25,000 miles ago and this weekend, while troubleshooting another problem, pulled the front cover to look at the belt. The belt looks fine but is looser than I would like. I'm hesitant to tighten it and disturb the water pump seals so my question is - how loose is too loose? Thanks. Bob Cummings