Last July Steven Dubnoff asked
"...I was wondering, at how many hours of use is it wise to replace one's
water pump impellers? If it makes a difference, this is on Detroit two
strokes. I need a conservative interval that will really reduce the chance of
failure.
Frank Burrows replied: (in part)
"....This is going to be the far end of intervals but my best guess based on
20
years of ownership of 2 6-71N Detroits is 5 years or 500 hours as a
reasonable replacement interval....These pumps don't have catastrophic
failures but lose a blade every once in a while and increase the temperature
slightly. .."
My experience is identical to Frank's with both 6V53's, more recently
8V71T's. The impellers die slowly, not catastrophically. First a blade cracks, then
eventually breaks off.
Last spring I replaced two impellers (Jabsco 17936-001). It was five years
and about 650 hours. The first was perfect...and I thought .."I just wasted
$80". But then I did the other engine and found three (of 12 ) impeller blades
had cracks at the hub...so it was worth it after all.
Be sure to check the faceplates and slotted cams for wear when the pump is
disassembled....especially the cam will eat blade tips....
I found 42 17936-001 impellers for sale on e-bay about three weeks ago. I
got two for about $66 including shipping. They are in original Jabsco boxes and
are perfect.
I almost bought the whole lot for subsequent auction but got
sidetracked....reading too much T & T likely...
Seasons Greetings,
Rob Brueckner
Hatteras Yachtfisherman
Last July Steven Dubnoff asked
"...I was wondering, at how many hours of use is it wise to replace one's
water pump impellers? If it makes a difference, this is on Detroit two
strokes. I need a conservative interval that will really reduce the chance of
failure.
Frank Burrows replied: (in part)
"....This is going to be the far end of intervals but my best guess based on
20
years of ownership of 2 6-71N Detroits is 5 years or 500 hours as a
reasonable replacement interval....These pumps don't have catastrophic
failures but lose a blade every once in a while and increase the temperature
slightly. .."
My experience is identical to Frank's with both 6V53's, more recently
8V71T's. The impellers die slowly, not catastrophically. First a blade cracks, then
eventually breaks off.
Last spring I replaced two impellers (Jabsco 17936-001). It was five years
and about 650 hours. The first was perfect...and I thought .."I just wasted
$80". But then I did the other engine and found three (of 12 ) impeller blades
had cracks at the hub...so it was worth it after all.
Be sure to check the faceplates and slotted cams for wear when the pump is
disassembled....especially the cam will eat blade tips....
I found 42 17936-001 impellers for sale on e-bay about three weeks ago. I
got two for about $66 including shipping. They are in original Jabsco boxes and
are perfect.
I almost bought the whole lot for subsequent auction but got
sidetracked....reading too much T & T likely...
Seasons Greetings,
Rob Brueckner
Hatteras Yachtfisherman
