[jst_4_kiks]

So much controversy over different types of impellars.

Alpha gen I = low volume, high pressure pump. Replace 2-3 years
Alpha gen II = high volume, low pressure pump replace 4-5 years or longer (depends)
Bravo = high volume, low pressure. 2-3 years
Volvo Penta = cross of Alpha 2 and bravo. 3-4 years (depends)

Belt driven pumps have good and bad qualities. Pump loads of water for cooling (ie big blocks 454, 502, 496, etc) belt driven also been on volvo penta for years. Some volvo sx drives have belt driven pumps on 3.0 & 4.3 engines.

Volvo impellars that are crank driven are very simple to replace. Can even be done with the boat in the water. I have done it numerous times. There is a small seal that rides on the end of the crankshaft that can wear out and cause a water leak. Some people have changed just the seal but I perfer to change the entire housing and not have to worry about the seals surface fit.

On all alpha 1&2, bravo impellars there is a date code molded into the rubber between the vanes. Its interesting to see that a gen1 impellar can sometimes make it 6-10 years sometimes. I don't see how, but it happens. Gen2. (Floppy vane) pumps last for a long time depending if you operate in a shallow sandy areas that cause wearing of the rubber edges and create uneveness in the housing. This will produce overheats and loss of water to cool the engine.

Basic information above. Can go on and on about the subject of impellars.