Theoretical question regarding water pump wear… - PeachParts Mercedes-Benz Forum

RunningTooHot · #1 10-09-2003, 01:08 AM

Has anyone ever run across a situation where a water pump has ended up with reduced pumping capacity due to the vanes becoming worn down from erosion (not corrosion) at high mileage? My water pump is original with almost 325,000 miles – believe it or not!

I am starting to suspect that the pump may not be displacing as much water as it should, but I don’t want to pull the pump just to inspect it; if I can rule out this possibility, it could save me some potentially unnecessary work. (I was thinking about replacing the pump just as a matter of course, but it’s not leaking – and I’m thinking about the old adage “if it ain’t broke, don’t fix it”.)

Thanks!

Glenn

Phalcon51 · #2 10-09-2003, 04:08 AM

At that high a mileage, I'd replace the water pump as a matter of course and chalk it up to preventive maintenance. Just one less thing to worry about on a long trip. I'm not sure if the rotor can erode enough to diminish output, but the only way you can rule it out for sure is to pull the pump and measure the clearances. At that point you might as well replace the pump. After 325K mi., I think you've gotten your money's worth out of it. If it ain't broke, and it's seen a lot of miles, replace it before you have to fix something more expensive!

Gary

Kestas · #3 10-09-2003, 09:46 AM

I rather doubt ANY erosion can take place on a water pump vane unless there is abrasive debris in the cooling system. I'm surprised the seal has held up this long.

If you're suspecting poor cooling performance, a likely cause is mineral buildup in the radiator. I've heard there are boiling techniques and rodding techniques to rejuvenate a radiator.