Raw water pump bits

[Salty Fresh]

I have a 2000 7.4 Mercruiser Bravo 3 with a hot temper.
I searched all the old threads and happily found how to trouble shoot and finally the problem. The raw water pump impeller on the engine side was in 20+ pieces. Literally every fin was mauled off and ripped to bits.
I backwashed from the manifolds, disconnecting at the oil cooler, steering cooler, and flushed out a lot of small bits.
Assembling the jigsaw puzzle, I'm missing around 10 % of the rubber maybe less.
Yes, it had never been changed before and roughly 350hrs on the engine.

So the question is do I need to remove the manifolds and risers or can I assume the remaining bits passed out or will?
The missing pieces will be very small and I'm hopefull you guys will tell me the manifolds and risers passages are large enough.

I really don't want to remove them for a few reasons but if absolutely...

Also, do the fins on the impeller need to bend a certain direction or will they just flip the direction required?

I bought the kit not just the impeller.
Thanks for your replys

 

[JustJason]

Re: Raw water pump bits

if the peices were that small they may have passed.
Have you pulled the t-stat housing and looked around in there?
The manifolds should be pulled if they have not been inspected in a while.

 

[Fishermark]

Re: Raw water pump bits

Have you pulled the t-stat housing and looked around in there?

I have an engine mounted raw water pump on my 5.7 engine and that's exactly where most of the pieces wound up on my engine. I would take off the thermostat housing and check. At the very least, pull the hose off and see if you can see any pieces there.

 

[Salty Fresh]

Re: Raw water pump bits

The manifolds and risers were changed last summer.

I thought the t stat was for the coolant side and was not involved with the raw water side? Am I wrong?

(The engine is closed cooling but the M&R'S are raw)

thx.

 

[Fishermark]

Re: Raw water pump bits

You should be fine with the closed cooling system - but that means you need to check the heat exchanger.

 

[Salty Fresh]

Re: Raw water pump bits

Would the back flush from the risers to the reservoir not have cleared it out?
I suspected it would be large passages in there?

 

[hard-3]

Re: Raw water pump bits

take the outlet hose from the oil cooler hose off of the thermostat housing and get a fitting from home depot that you can adapt to garden hose fitting. put on hose and take the hose loose from the raw water pump and back flush the oil cooler power steering cooler with garden hose pressure.any small pieces of impellar will flush back. try to catch in a bucket or an a clean white rag to see if you get pieces . if it's closed cooling system do the same at the heat exchanger. you may not find little tiny pieces that were small enough to pass through and go out exhaust. if it's raw water cooled take thermostat housing out and check for pieces there also. flush entire motor if possible .