Water Pump Impeller Replacement

[Dave R]

Originally Posted by 8gv

Thanks for the tips.

I'll call Mercruiser Monday morning to see if they have a complete kit for this. Their parts site shows only the individual parts.

I may consider aftermarket.

Has anyone here had any experience with going non oem for this?

The merc part number for the rebuild kit is 46-807151a14, though it may have been superceded. Bravo pumps have not changed since 1988 or so, so it should not be hard to find a kit. Aftermarket is fine.

If the old impeller is broken into pieces, you'll need to back-flush the system from where the raw water enters the thermostat housing, back through the oil cooler, fuel cooler (if applicable), and power steering cooler, to the pump outlet. The pieces usually get trapped in the power steering cooler and can cause enough restriction to make your engine overheat at speed.

[8gv]

Well that was fun...

I got a late start because my daughter's car quit and stranded her today.

New Rule: Only one broken machine at a time!

The pump is out of the boat and I did more stretching exercise today than I thought possible. I suspect my motion tomorrow will have a sound track of groans.

What started all this is the pully shaft and a bearing migrated out of the pump housing. The pully looks fine but will have to be removed from the shaft with, you guessed it, a puller.

I suppose it will then need to be pressed onto the new shaft of a new housing.

Hopefully the Mercruiser help line can steer me in the right direction on this.

The two hoses, red on top and black on the bottom, were not very long and as a result reaching their clamps was challenging. Reassembly will likely be much worse.

It looks like the impeller is undamaged so I won't need to go on a cooling system scavenger hunt for bits and pieces.

I hope to have this wrapped up this week.

[Hillcountry]

Originally Posted by 8gv

Well that was fun...

I got a late start because my daughter's car quit and stranded her today.

New Rule: Only one broken machine at a time!

The pump is out of the boat and I did more stretching exercise today than I thought possible. I suspect my motion tomorrow will have a sound track of groans.

What started all this is the pully shaft and a bearing migrated out of the pump housing. The pully looks fine but will have to be removed from the shaft with, you guessed it, a puller.

I suppose it will then need to be pressed onto the new shaft of a new housing.

Hopefully the Mercruiser help line can steer me in the right direction on this.

The two hoses, red on top and black on the bottom, were not very long and as a result reaching their clamps was challenging. Reassembly will likely be much worse.

It looks like the impeller is undamaged so I won't need to go on a cooling system scavenger hunt for bits and pieces.

I hope to have this wrapped up this week.

Good luck! I know full well about paying in pain for attempting to accomplish impossible tasks!

[8gv]

I tell myself "Humans do this. I am a human, therefore I can do this."

Of course, training, experience and the lack of special tools often get in the way.

One thing is certain, I will learn from the experience.

[Dave R]

Originally Posted by 8gv

Well that was fun...

I got a late start because my daughter's car quit and stranded her today.

New Rule: Only one broken machine at a time!

The pump is out of the boat and I did more stretching exercise today than I thought possible. I suspect my motion tomorrow will have a sound track of groans.

What started all this is the pully shaft and a bearing migrated out of the pump housing. The pully looks fine but will have to be removed from the shaft with, you guessed it, a puller.

I suppose it will then need to be pressed onto the new shaft of a new housing.

Hopefully the Mercruiser help line can steer me in the right direction on this.

The two hoses, red on top and black on the bottom, were not very long and as a result reaching their clamps was challenging. Reassembly will likely be much worse.

It looks like the impeller is undamaged so I won't need to go on a cooling system scavenger hunt for bits and pieces.

I hope to have this wrapped up this week.

Sounds like the rebuild kit I recommended will be of no use to you, it replaces all the parts that are still good on your pump. Sad to say, you will need the more expensive parts of the pump that should have lasted much longer...

If you would like to try and rebuild the shaft, pulley and bearing part (the "nose housing") of your pump, I'd love to give it a go, just for the experience, I've never done one of those. I have all kinds of tools for this kind of work in my garage here in Raymond.

[8gv]

Update:

It's raining and 53° so the installation will have to wait until tomorrow.

I now have in my possession a complete new pump.

I "borrowed" a pulley puller kit from AutoZone. Their program allows you to buy the tool with the expectation of returning it for a full refund.

The puller worked well so the pulley is off the old shaft.

I expect it to be easier to install the pump first and then add the pulley. A practice installation with the pulley tool showed me it will be easy to do.

Mercruiser telephone support gave me some tips:

A touch of motor oil on the pulley shaft.
Dish washing soap will aid in hose installation.
Some torque specs.
The new pump assembly is better because it has a circlip to retain the shaft in the housing.

My flushing earmuff flood abatement was adequate for removing the pump but I will augment that with the trash bag technique suggested here (thanks).

If any of you up in Wolfboro hear a tirade of cussing tomorrow it will be me down here in Paugus Bay applying some "verbal lubrication" to the task.

[Dave R]

Originally Posted by 8gv

Update:

It's raining and 53° so the installation will have to wait until tomorrow.

I now have in my possession a complete new pump.

Whatcha gonna do with the old pump?

[8gv]

Originally Posted by Dave R

Whatcha gonna do with the old pump?

Sell it to you for big bucks!

[Dave R]

Originally Posted by 8gv

Sell it to you for big bucks!

Not familiar with this "buying something for big bucks" concept. Goes against ever fiber of my being... Seriously though, if you want, I'd love to take a look at it and see how hard it would be to fix. I live for stuff like this.

There's a Mercruiser 454 with new head gaskets, valve seals and recently lapped valves in my garage right now that I'm working on for/with a friend for fun. Should be dropping it back in his boat this weekend.

My best find ever (so far): I recently bought a complete 2005ish Bravo 3 lower gear case with only 22 hours on it, for 25 bucks (these are $3400 new). Has some minor corrosion, but is in perfect working order. I did not rip the seller off, I made sure he was aware that it was a ridiculously good deal; he had sold his boat, was moving to TN, and just wanted it gone but not wasted. I was simply looking to re-stock my spare parts bin after changing an outer prop shaft, bearing carrier, and seal, on my boat's Bravo 3.

[8gv]

The pump is in and everything is buttoned up.

Water PSI and temp are good, serpentine belt is running smoothly.

Thanks for the advice given here, especially the suggestion of using a trash bag to keep the water from entering. That plus the earmuffs gave me ZERO water coming in.

The new pump is half brass and half ABS. I will hang onto my old brass one in case the ABS part gives me trouble.

I might have paid a shop to do this but the down time durring the season would have been too much for me.

I now know more than I did before.