Originally Posted By: IndyIan
Water pumps don't fail suddenly though do they? One on the Neon dripped for quite a while before I got around to replacing it. Same with alternators too I guess, you need a real voltage gauage to see it go though.
Not usually. My mother's Sunfire, for example, went 2000 km on a leaking water pump before I replaced it. It was dripping onto the driveshaft near the seal, and since the coolant was Dex-Cool it was reddish and I thought that a little bit of ATF was just seeping out when I looked for the source of the drops she had noticed on her garage floor. It got progressively louder, until it was obvious to her that there was a bearing problem somewhere under the hood and she asked me to look at it.
I've replaced three alternators in my life. All gave plenty of warning. It's probably much more likely to have a sudden failure with the electronics in that compared to a simple mechanical device like a water pump though.
I wouldn't change the pump. I don't even change the belt until there's some signs of aging, like any crack in the rubber on the non-ribbed side or severe cracking on the ribbed side. I give belts a good visual inspection before any road trip.
