525 EFI Raw water pump
 

Just got the boat out of storage and was running it to get the oil warm to change when i noticed that my temp was high and then not spitting water out the back. So i took the hoses off the pump and sure enough i pull out black powder and chunks. And of course i leave for lake norman on wednesday. So my question is can the impeller be replace without removing the pump? Is there any thing special that i should be checking or looking for? If I can't get the parts in time does anyone have a place and # for a place around norman to take it too.

Since it is so close to the big weekend it might be a little hard to get in to a boat shop right now, So you might need to brake out the tools and try it your self would be my guess. It's normaly easyr to take off the pump off the engine block and do it out side of the boat. Try to find all the old parts of the impeller, Shake out the hose that goes to from the pump to the engine looking for old parts and if you can't find all of them then you will need to trace the hoses around the engine and try to back flush the system till you see the water coming back out the hose you took off the impeller housing and let it drain out the bilge drain plug with the bow as hi as you can go. It's normaly around a 2-3 hr job till you get used to it. is there a lot of room in that area of your boat?

I have no problem doing the work myself. Hopefully I'll be able to get one around here so that i can get it done while i know i have all the tools that i need. I have tons of room to work on that side of the engine and can get directly behind it but i just wasnt sure if it had to be removed or not. Do i need just the impeller or is it better to get the whole rebuild kit? Is it the same part for all merc big blocks or is it engine specific?

Depending on the years they have around 3 kinds, You WILL need you engine serial number off the engine so you can be sure to buy the right one. You can buy just the impeller or you can buy a new housing kit that comes with the impeller, It all depends on if the housing has deep groves in it or not, But I will say this more then most have groves in them and need A new housing. If that helps you or not it up to you. If you have the plastic housing it is around $100.00 if you have the brass housing it is almost $600.00. Or just the impellers by them self, Both of them are around $40.00. Good luck with it, And I'm sure by now you have read most of the past post on how to install it right? If not I'm sure we could try to help you out if needed.:)

Buy the kit, around 100 bucks and you get a new housing. The housing is plastic so if you damaged the impeller you damaged the housing. You should have the plastic housing pump on a 2008 525. Not that hard to change if you have room in front of the engine. Just remember to put the hoses back where they came off from.

Both my mechanics recommend replacing the impeller and housing when this type of thing happens.

Make sure to backflush to get all the pieces out.

This is the part number i found locally but the dealer didn't even know what a 525 EFI was so if anybody can confirm this it would be greatly appreciated.

46-807151A14

It's a pain but doesn't take too long.

That is the correct part number and it is possible to change the housing and impeller with the pump on the motor. There are 5 bolts through the back of the housing that need to be removed as well as the hoses to the back of the pump and the serpentine belt, make sure you find all the pices of the impeller as they tend to sometimes travel through the hose to the oil cooler and grease the impeller and housing well before re assembling

DIY .... it is really easy. Just take your time and all will be fine.