Does serpentine belt run water pump 02 WH 8.1

Lots of good advice by posters for you! The answer to your question is yes.

One is a Dayco KEVLAR and the other is a std Gates. I have to think the Kevlar would be better.

I had good luck with the Gates brand of belts and poor luck with the Dayco brand.
To make it easier to change, I used a 3/8" breaker bar and a small ratchet strap. I used the strap to hold the tensioner which left me with both hands free to put the belt in place. At the side of the Interstate in Iowa I found it is a 15 minute job to replace a broken belt.

You can tell when a serpentine belt needs replacing by just looking at the underside of the belt. If you see that it is cracking and starting to flake off, it is time to change. Forty five thousand miles is not much, so it probably is still good. I have sixty thousand on my Caterpillar engine, and according to Freight liner the belt does not need changing yet. So I just bought both belts and carry them in a compartment in case one breaks. I am going to keep an eye on them though and am shooting for ninety thousand before I insist that they change them out.

Got 2 belts and tensioner and idler pulley in the MH in case I need them.

Whenever I replace the serpentine belt I also replace both the tensioner and the idler pulley. My experience is they both seem to be sources of belt failure.

Brakes will switch to electric if power steering pump fails (or belt breakes)

Water pump is run by the Serpentine belt. Yes, so is the engine's fan, alternator, and Power Steering Same as any car.

Mine switches to electric brakes if the belt breaks but not positive on a 2002 model. I thought that only the W chassis uses the 108" belt but it is better to make sure. You also may have two idler pulleys with one fixed and one on the tensioner.

**** computer can't spell!

enblethen wrote:
There should be only one belt that drives everything. 108 incher. If it brakes you also loose brakes if equipped with hydro boost working off the power steering pump.

actually if it "Breaks" u will loose "braking" power