Does a water pump impeller wear?

[W0QNX]

My bike has 255,000 miles on the original water pump. It seems like (uhoh bad diagnosis) it runs hotter now days. I have moved to Florida where it's usually warm (hot!) but it has me thinking. Did I once see an impeller on here that had worn down blades or was that on the KLR site?

IF you've replaced the water pump at several miles what did the impellers look like?

Thanks.

 

[SupraSabre]

They look like they are ready for another 100,000. It's the seals and bearing that wear!

 

[CruSTy]

I’ve not changed a WP on an ST1300. I have replaced more water pumps on Honda cars than I can count. I have seen some with NO IMPELLER upon removal. The impeller is stamped steel and the engine block is aluminum. Perfect recipe for a battery if your engine coolant is sour and electrolysis will eat the steel impeller blades right off the pump. Needless to say the engine will run hot if you are not pumping enough coolant. Best have a look see.

Chuck

 

[SMSW]

Yes, somebody here posted a pic of a water pump w/ worn impeller blades. IIRC, he adaped a pump from some car. But the seals and/or bearings usually go first, as CruSTy said. Btw, mother honda's service manual says to change the juice every two years (brake/clutch fluid too).

If you do end up changing the pump, be very careful seating the new one, it is supposed to go in the casting to a certain depth - check the SM.

 

[Upt' North]

I haven't changed one on an ST, but yes if the coolant gets a little long in the tooth they can and do disappear.
Although I would have thought the overheating symptom would be more severe.
Thinking out loud could you see in there if you removed a hose or two.
Upt'North.

 

[SupraSabre]

Gee, I guess the three that I've changed must have been made out a of a different material! None of the propellers had ANY wear on them!

But I do change my coolant every couple of years.

But they do say to replace them just in case the removing/installing new seals and bearings "might" nick the shaft!

 

[Upt' North]

This is what may be going on.
I've only seen examples like this on LGV's / trucks in the good old days. When they were overheating the drivers would fill them up from streams or even pee in the expansion tank. I don't know what the antifreeze quality of pee is, I'm guessing not good.

 

[W0QNX]

Gee, I guess the three that I've changed must have been made out a of a different material! None of the propellers had ANY wear on them!

But I do change my coolant every couple of years.

But they do say to replace them just in case the removing/installing new seals and bearings "might" nick the shaft!

Ok then I'll consider mine fine until something leaks! Probably no hotter than ever before it's just it's always warm when I ride! And I like that much better than cold.

 

[SupraSabre]

Ok then I'll consider mine fine until something leaks! Probably no hotter than ever before it's just it's always warm when I ride! And I like that much better than cold.

If it doesn't go over 3 bars, I wouldn't worry.

Also, when you do decide to replace your waterpump, I would replace your clutch plates as well. Because of my commutes, my clutches don't last as long as some that just rides without traffic. @ 255K, it sounds like most of your riding is without stop-n-go involved. But I would bet that you'll feel the difference once you replace it and the clutch slave too. I know, I just keep adding things on!

 

[treemuncher]

Water pump impeller can wear but rarely do unless debris or chemical reaction is affecting it.

Have you checked the cleanliness of your radiator? Make sure you can see plenty of light through it and you don't have too many bent fins. A heavy coating of dust or debris will choke down cooling efficiency quickly. (Alaska trips?) I deal with this all of the time with my machines. Soak with a degreaser and then pressure wash with at least a 15 degree tip or wider and set no higher than 2k psi. If fins bend, more distance and less pressure between tip and radiator.

There are also some coolant additives that claim better cooling dfficiency.

 

[mortenk]

This is what may be going on.
I've only seen examples like this on LGV's / trucks in the good old days. When they were overheating the drivers would fill them up from streams or even pee in the expansion tank. I don't know what the antifreeze quality of pee is, I'm guessing not good.

Depends on your alcohol intake last night...