Raw water pump question

[Nmor830]

Recently had to replace the raw water pump on my 2008 34 sundancer. Found an on line company that advertised new OEM pumps as well as rebuilt. Already went through a headache with another replacement so decided to go brand new. My understanding is there is not a stainless back plate behind the impeller on the original OEM pump. Is that correct? The pump I received when looking closely has a SS back plate behind the impeller. This makes me think it’s a rebuilt. I’m ok with this as it’s probably a better design however I’m not ok with the big price difference. I paid for new pump not a rebuilt.

Before I go off on them I want to be sure I know what I’m talking about. I showed it to a mechanic friend, he tells me it’s a rebuilt. Just wanted other opinions to be sure.
Thanks,
Nick

 

[Jimmy Buoy]

OEM pump housings are brass. The one issue with them is that the brass can wear (especially in sandy water conditions) creating a series of grooves in the housing at both ends of the impeller. Eventually these grooves prevent the pump from moving sufficient water. Usually the fix is another new pump, or even more expensive a new stainless pump from Hardin Pumps. I think wear plates are a better idea.
In my case, I decided to go with a company that provides two stainless wear plates, a shorter 1.7" impeller designed to fit the pump with the wear plates, and a gasket for $110 and haven't had any issues since replacing it a few years ago. Here's the link...

http://www.amarket.com/im496reb.htm

 

[Thornton69]

Were you charged for a core or asked for yours to be returned? If not, then it is more than likely new or it is modified from a new component.

 

[Nmor830]

Were you charged for a core or asked for yours to be returned? If not, then it is more than likely new or it is modified from a new component.

Yes they requested the core be returned. They were honest and admitted it was a rebuilt sent my mistake and have offered a refund for the difference. The stainless back plate is a good idea as long a the impeller isn’t effected as Jimmy mentioned.

 

[Nmor830]

OEM pump housings are brass. The one issue with them is that the brass can wear (especially in sandy water conditions) creating a series of grooves in the housing at both ends of the impeller. Eventually these grooves prevent the pump from moving sufficient water. Usually the fix is another new pump, or even more expensive a new stainless pump from Hardin Pumps. I think wear plates are a better idea.
In my case, I decided to go with a company that provides two stainless wear plates, a shorter 1.7" impeller designed to fit the pump with the wear plates, and a gasket for $110 and haven't had any issues since replacing it a few years ago. Here's the link...

http://www.amarket.com/im496reb.htm

For want it’s worth, I tried the SS Hardin pump with not such good results. The pressure was much lower and the engine ran much hotter. Even swapped pumps (strb. port) and the other engine also ran about 15 degrees hotter with the Hardin. May not be typical but was my experience. I’m hoping the rebuilt oem will be a working replacement. Next time around I’ll look at the SS back plate replacement kit. You would think the original oem pump manufacturer would have figured this out by now.

 

[Jimmy Buoy]

Yes they requested the core be returned. They were honest and admitted it was a rebuilt sent my mistake and have offered a refund for the difference. The stainless back plate is a good idea as long a the impeller isn’t effected as Jimmy mentioned.

Are there TWO backing plates, one on the open end and one in the bottom of the housing? If there is one just on the open end it would not affect the impeller size required, but if there is one in the bottom it would require a shorter length impeller (shortened the same thickness of the stainless plate) or it would be too tight a fit to spin.

If there is only ONE backing plate, it will only solve half of the pump's issues if the housing begins to develop deep groove wearing from sand in the cooling water.

This is a bad choice making the housing out of relatively soft brass for the owner, but a good revenue stream for both the pump supplier and dealers who service them...