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I am getting ready to replace the impellers on these pumps. It looks like the best way to remove the pump is to take off the pump and the pump bracket as a unit. The other option would be to remove the pulley from the front of the pump, release the pinch bolt which holds it to the bracket and slide the pump aft, leaving the bracket in place.

What is the preferred way to do this?

Peter

It has been a while for me, but if I remember right, I loosened up the belt and then just unbolted it and it came right off. I did not remove any brackets, just a couple of bolts.

Do you still have the manuals I sent you. See if what they show in the manual is the same set up. I remember the starboard one was a pain. because I had to lay on top of the engine and stick my head up against the bulkhead to see what I was doing.

Tony,

The manuals do not show the details of how the pump is mounted. This link (if I did it correctly) shows the setup that I have. Part # 26 is the bracket with the pinch bolt.

https://www.perfprotech.com/mercury-mar ... br=47489A2

I think its going to come down to 6 of 1 or half dozen of the other...

If you cannot service the pump in place...usually by pulling the rear cover the pumps gotta come out.

So is it easier to loosen belt and adjust bracket, remove front pulley, loosing pinch bolt, wedge open bracket and wiggle pump from bracket.

Service the pump and reverse procedure to install.


It may depend more on your access...

Me...what is directly accessible, taking apart the least amount of items would be my first approach.
AND I'm thinking a painted pump is not going to like being slid out of a painted housing. Plus you need room behind to maneuver pump in and out.

1 Bolt for adjusting bracket, 2 bolts to remove bracket with pump. If accessible my gut say that's my direction and leave that pulley alone.


I have not seen your setup to offer a real world what was best.

Peter-
On my engines (1992 454 Crusaders) I loosen the mounting bolts (they go through the mounting bracket from the bottom into the pump base) and then back off a tensioning bolt that slides the base of the pump outboard. Once loose enough for some slack in the belt I remove the mounting bolts and the pump comes out. I have removed the mounting brackets as well to de-rust them but not frequently.
I have found that the O rings supplied with the impeller kit (https://www.amazon.com/Sherwood-Blade-I ... 872&sr=8-2) do not fit my pumps.
For the first few years I had a small piece of plywood with a hole the same size of the impeller housing that I used as a block to pry the old impeller out - making sure not to damage the flat surface where the cover seals. I have more recently splurged and bought an impeller puller tool. In any event some Tef-Gel or the lube of your preference makes it easier for next time.
Best,
Stephan

Thanks for all of the responses. I am leaning toward removing the pumps with the bracket which brings up another question:

One of the two bolts which secure the bracket to the block is DIRECTLY behind the hose which runs from the water circulation pump (fresh water coolant side) to the heat exchanger. Since I cannot budge that bolt it with an open end wrench, it looks like I will need to drain the coolant and remove the hose so that I can get at it with a socket and breaker bar. Even if I were to successfully loosen this bolt, I suspect that reassembling things will be difficult if I have to work around this hose.

Based on the manuals that I have, I understand that the drain for the block is a petcock (in my case a bolt), directly above the transmission oil cooler (port engine). I don't see an easy way get a pan under the engine at that spot to catch the antifreeze. Any suggestion here?

I use the 2€ hand pumps from supermarkets for transfusing olive oil from the metal containers into bottles. A micrography of a normal hand pump really, that fits the antifreeze hole.
A good portion of the antifreeze can be extracted this way, the rest let it flow in the bilge and get it with a sponge.
On second thought, you can also use this device used for transfusing fuel, the one with the squeeze thing that creates the Bernoulli effect. As this is more flexible, it may even be more efficient in reaching lower inside the motor.

Peter-
Thanks for posting the diagram of your pump. I did not see that before my earlier post - our pumps are different.
I have drains in the exhaust manifolds that are pretty good at getting the coolant level down low, they are also easy to get a funnel under as they are on the sides of the engine. Might that be an option for you?
Best,
Stephan

Stephan,

I do have drains on my exhaust manifolds. I will try those before I resort the siphon.

The hose your removing....can you put a container under it? Container with funnel?


Not saying it's an easy job...but raw water pump maintainance is supposed to be a yearly thing. Something that might have to be tackled when out on the water. The people marinizing the motors don't make many items easy to tackle, but raw water pumps being what they are tend to be somewhat straight forward to change out an impeller. Dropping fresh water coolant does not seem right. I'm not saying it cannot be done that way...just wondering if there is a more direct approach.

Draining coolant always seems to end up with a lot of it in the bilge no matter what you do--a few years ago I came up with a simple modification that fixes the problem. I replaced the petcocks on each side of the block (which is the lowest drain point on the engine) with a hose barb, ran a 3/8 hose from each to a t-fitting and 1/4 turn valve mounted on the inboard engine stringer at the forward bulkhead. Now if I need to drain coolant I just put a container under the valve, open the pressure cap and open the valve--coolant flows directly into the container without spilling a drop.

I had another go at it and wedged a screw driver into the slot in the bracket. Then I used a hammer handle against the pulley flange to push the pump aft and remove it.

Starboard side is actually pretty easy to access after removing the outboard strip of shrouding.

Thanks for all of the encouragement.

The pump on the starboard engine is a Jabsco and fits a bit more loosely in the bracket so it slid back easily when I undid the pinch bolt.

I replaced both impellers although they showed no obvious wear or damage after three seasons.

When the yard put me into the water on Tuesday, I could see a good flow out of the exhausts and engine temperatures were stable.

pschauss wrote: ↑Apr 3rd, '21, 12:27 I could see a good flow out of the exhausts and engine temperatures were stable.

Well done then...
Thanks for sharing the good outcome.
Stephan

I use my “Lowe’s” small wet dry vacuum to suck out as much antifreeze from the heat exchanger as I can.
Once that is empty I disconnect the bottom hose from the heat exchanger and suck the rest out.
I fully clean the vacuum cleaner before I start and then can reuse the antifreeze

Luckily I was able to get the water pumps out without removing the hose from the circulation pump to the heat exchanger.