mherrcat
Contributing Partner
In replacing the impeller on my Sherwood water pump (M-18 engine) I have discovered that the backing plate behind the impeller housing is slightly scored - we're talking .001" to .002".
Can I try to "lap" that side of the plate surface to make it smooth again, and is .002" difference in the thickness of the plate going to make a difference in the function?
I read Maine Sail's writeup on water pump rebuilds and he mentions flipping the plate over; but he is talking about a pump model where the plate is on the front of the pump. (Making any difference in the plate thickness no problem.) I can't just flip my plate over because there is a gasket that goes between the plate and the pump body, so that side of the plate has to be smooth also.
Below is a link to the parts diagram for my pump. The part in question is number 17. The replacement part is only $19.47 so I plan to purchase one; I just wanted to keep the old plate as a backup.
www.marinedieseldirect.com/catalogs...ncludes a replacement pump).&incontext=302648
(Edited to make the link work...)
Can I try to "lap" that side of the plate surface to make it smooth again, and is .002" difference in the thickness of the plate going to make a difference in the function?
I read Maine Sail's writeup on water pump rebuilds and he mentions flipping the plate over; but he is talking about a pump model where the plate is on the front of the pump. (Making any difference in the plate thickness no problem.) I can't just flip my plate over because there is a gasket that goes between the plate and the pump body, so that side of the plate has to be smooth also.
Below is a link to the parts diagram for my pump. The part in question is number 17. The replacement part is only $19.47 so I plan to purchase one; I just wanted to keep the old plate as a backup.
www.marinedieseldirect.com/catalogs...ncludes a replacement pump).&incontext=302648
(Edited to make the link work...)
Last edited: