The three belts (Alternator, PS Pump, AC) on our '90 Westy are due for replacement. I can do the job - that's not the problem. The question is "how tight is tight?" Typically, I've gone for 1/4" deflection in the middle of the longest run between the sheaves (AKA pulleys - being pedantic, that's not the right name for the grooved wheel on a pump, etc.). But maybe that's too tight, too loose?