Replacing Mercruiser Stock Raw Water Pump on 350 MAG MPI.-gctid406273

[TenMile]

[edit: below is a bit of an adventure I had with faulty Mercruiser water pumps -- went through 3 of them in a span of 3 years. Finally decided to swap the belt driven pump for a crankshaft mounted pump -- lower cost, better design, much easier annual maintenance etc... -- feel free to read through the series of posts, or I will summarize in the conversion steps and some lessons learned in the last post}

Hey all -- need your help and input.

Have my boat way around the west coast of Vancouver Island for the month of August. Opened the engine compartment to find several inches of water in the bilge area and water dripping from the shaft/bearings of my SeaWater pump.

I've got a Mercruiser 350 MAG MPI, 2004 vintage that uses the late model pump -- part number 862914C (or the new model uses T10 rather than C).

Looks like I have a few choices:

1. Risk not replacing it and run the pump as-is. But given I'm fishing offshore, I'm thinking this is a stupid decision as the bearings are going to eventually seize (it's a matter of when...)

2. Replace the entire pump assembly: however, none of the Mercruiser parts dealers have the pump in stock as apparently there is a "casting issue" with the manufacturer and they have been backordered since June or earlier with no stock expected anytime soon....

3. Find an after-market pump (eBay or otherwise)

4. Replace the shaft and bearings on the existing pump.

I'm looking into options 3 or 4. Have any of you rebuilt the pump yourself? I can get the shaft with the bearings and seals new for about $135 but not sure if this is something I can tackle on the dock, 3 hours (by road) from home? Can any of you comment whether this rebuild is relatively simple? The parts diagram is here -- and quoted replacements are basically parts 2-7.

Would also like comments on how difficult removal of the old pump will be. Looks as simple as removal of the two hoses (block the water intakes), remove the belt, remove the hanger bracket and the pump should be in my hand. Concerned that the hanger bracket looks pretty rusty -- any tips for easy removal?

[Go Aweigh2452]

I too had issues trying to get a new seawater pump and it was back ordered in Mar, then April, then May, then June. In the mean time I changed over to a crank shaft mounted Johnson seawater pump. Less expensive to replace, lasts longer, easy to replace the impeller.

Attached files [img]/media/kunena/attachments/vb/710023=30403-johnson.jpg[/img] [img]/media/kunena/attachments/vb/710023=30402-pumpinstall.JPG[/img]

[2850Bounty]

Take a look at Doug C's Johnson Raw Water Pump Installed on 6.2 thread in the Completed Projects section, and see if there are enough similarities to make this worthwhile for you.

In my way of thinking, if we can eliminate a belt driven pump, we're ahead of the game.

Edit: Doug, it apparently took me 3-1/2 to 4 minutes to post this right after you pulled the trigger!

.

[TenMile]

Interesting -- didn't know that option existed.

So I take it, this would mean:

1. Removal of old pump? If old pump is removed, does this mean that the belt has to be replaced?

2. Extend the intake/distribution hoses (I'd have to extend mine as I have no way to remove the boat from the water until it's back in Victoria).

Would you think this is a fix I should attempt at the dock 3 hours from home with limited access to tools and shop?

[2850Bounty]

TenMile wrote:
Interesting -- didn't know that option existed.

So I take it, this would mean:

1. Removal of old pump? If old pump is removed, does this mean that the belt has to be replaced?

2. Extend the intake/distribution hoses (I'd have to extend mine as I have no way to remove the boat from the water until it's back in Victoria).

Would you think this is a fix I should attempt at the dock 3 hours from home with limited access to tools and shop?

That's because Mercruiser will never mention this to anyone.

Terry, it would be best if you were to read Doug's thread, and then decide how similar your set up is to Doug's previous set up, you may be able to take everything that you need with you, and make it a one-shot-deal.

There's a link to it in my previous post.

My only involvement was the pump recommendation, Doug did all of the changes and modifications.

You may be able to talk him into sharing his tricks, p/n's, what-changed-what, the new serpentine belt p/n, etc.

Do this just once, and your pump impeller maintenance will be simple and easy from here on out.

.

[TenMile]

We posted over one another. Just read it and it answered my questions. This one looks a little too risky to convert while I'm in a remote locale with no access to parts. Does anyone know if Johnson or someone sells a conversion "kit"? Tried to Google it, but nothing pops right up.

[2850Bounty]

TenMile wrote:
We posted over one another. Just read it and it answered my questions. This one looks a little too risky to convert while I'm in a remote locale with no access to parts. Does anyone know if Johnson or someone sells a conversion "kit"? Tried to Google it, but nothing pops right up.

Terry, Johnson, Jabsco and Sherwood are Marine household names, and all three have offered crankshaft pump like this since the late 70's.

They've been OEM on Indamar, PleasureCraft, MarinePower, Volvo Penta, Crusader, and probably a few that I'm forgetting right now. This style pump fits into the "open architecture" arena, so the companies that like to keep their systems proprietary, won't be using them.

I think Doug said his OEM pump was over $600.

The Johnson F5B-9 can be found for as low as $150/160 some times.

The F6B-9 is a bit more $$$$, but not much.

Johnson seems to have the market cornered right now regarding price.

https://"http://www.google.com/searc...nkshaft pumps.

https://"http://www.google.com/searc...nkshaft pumps.

https://"http://www.google.com/searc...nkshaft pumps.

[TenMile]

Sorry, to be more clear, by "conversion kit" I meant more like a specific cookbook of the parts I'd need for my specific engine (hoses, hangers, grommets, clamps etc). By risky, I meant that there is a high degree of likelihood that I arrive at the boat (3 hours by car) with the wrong stuff and totally mess up both my old pump and the conversion leaving me boatless.

I'd love to do this conversion but think it's better to attempt it when the boat is safe at home and I'm close to a parts shop.

[Guest]

TenMile wrote:
Hey all -- need your help and input.

Have my boat way around the west coast of Vancouver Island for the month of August. Opened the engine compartment to find several inches of water in the bilge area and water dripping from the shaft/bearings of my SeaWater pump.

I've got a Mercruiser 350 MAG MPI, 2004 vintage that uses the late model pump -- part number 862914C (or the new model uses T10 rather than C).

Looks like I have a few choices:

1. Risk not replacing it and run the pump as-is. But given I'm fishing offshore, I'm thinking this is a stupid decision as the bearings are going to eventually seize (it's a matter of when...)

2. Replace the entire pump assembly: however, none of the Mercruiser parts dealers have the pump in stock as apparently there is a "casting issue" with the manufacturer and they have been backordered since June or earlier with no stock expected anytime soon....

3. Find an after-market pump (eBay or otherwise)

4. Replace the shaft and bearings on the existing pump.

I'm looking into options 3 or 4. Have any of you rebuilt the pump yourself? I can get the shaft with the bearings and seals new for about $135 but not sure if this is something I can tackle on the dock, 3 hours (by road) from home? Can any of you comment whether this rebuild is relatively simple? https://"http://www.marinepartsexpre...iagram is here -- and quoted replacements are basically parts 2-7.

Would also like comments on how difficult removal of the old pump will be. Looks as simple as removal of the two hoses (block the water intakes), remove the belt, remove the hanger bracket and the pump should be in my hand. Concerned that the hanger bracket looks pretty rusty -- any tips for easy removal?

This is likely your pump.

It probably needs new bearings and seals.

The shaft is stainless and should clean up quite easily.

The problem is your location you need a bench and a few tools to do the job.

The crankshaft pump is likely easier but be sure you have enough room in front of your engine.

To do it you will need extra hose and fittings to join to your existing hoses.(likely easier than changing the complete hoses in the field and less likely of getting a flood.

http://www.mercruiserparts.com/Show_Pictures3.asp?dnbr=8M0049000&ivar=images/COMMON/45017.png&inbr=15322&bnbr=300&bdesc=Sea+Water+Pump+Assembly

[TenMile]

Anyone know if this kit would work do to the conversion? Seems to include the pump, bracket and bushing. Would just need the hose extension, barbs and clamps and then the new belt.

http://www.perfprotech.com/store/product/Crank-MountedDriven-Sea-Water-Pump-1-14-Inlet-Outlet-524505A,25229.aspx

[TenMile]

Ok, we're getting closer here. Found a good thread that seems to indicate the new belt that's required.

[2850Bounty]

Terry, the Johnson (or Jabsco or Sherwood) crankshaft pump installation that Doug did, is not using a kit, per 'se.

Like said, these pumps are quite common on many marine applications.

You'd need the crankshaft pump (choose the correct volume), three new mounting bolts, a torque arm (optional, IMO), and you'll need to modify the suction and supply hose routing.

This apparently is a crankshaft pump kit, but is for an Alpha drive.

With the A drive, the sea water pump is in the lower unit, and must remain functional for upper unit cooling.

This kit routes the A drive pump supply into the Johnson pump supply side.

I've done these before, but have always routed the A drive supply into the Johnson suction side.



Anyway..... it's a moot point because you'd simply be disabling a belt driven pump, and would be replacing it with a Crank Pump.

I agree with Cliff...... you'll want the Merc pump on your work bench for the over-haul. That means several trips back/forth.

My guess would be...... if you had all of the parts with you for the Johnson pump installation, you may be able to do it in about the same amount of time..... perhaps a bit more.

None-the-less, the goal is rid yourself of the more expensive and more difficult to service Merc pump.... Yes/No?

Do note that you must have enough space in front of the harmonic balancer for this to make sense.

.

[TenMile]

So got out to the boat this weekend and successfully completed a replacement of the water pump. I went off the board and chose the "phone a friend" option. Buddy of mine has the same engine in his boat -- I was calling looking for advice on the pump replacement as I knew he had done this before. As it turned out, he had a water pump he had removed from his boat a few months ago thinking it was damaged -- but it was in great shape. Exact same part number as my old one -- very lucky.

4 bolts and 2 hoses removed, and the old pump was in my hand. Had a local shop remove the pulley and install it on the new pump and got it mated up and mounted in about 30 minutes. Started and ran the boat and no more leaking.

The old pump was done. I warmed up the engine prior to removing the old hoses and the pulley was vibrating very badly so the bearings were basically shot.

[Guest]

(2002.6.2 MPI) I just had my water pump replaced as well. We were cruising the Chesapeake for a week and I noticed water in the bilge. Managed to limp in to a dock where the mechanic said he couldn't find any. I was able to locate one at Jackson's Marine in Northeast MD. Cost was about $365.00 with a discount.

Mechanic took over 4 hours to remove the pulley from the rod. Finally got it together, but now I have some vibration due to the pulley not being replaced exactly straight. He said it would not cause any problems, but I'm not so sure.

I didn't want to hijack a thread, but am I OK?

[2850Bounty]

bmetros wrote:
(2002.6.2 MPI) I just had my water pump replaced as well. We were cruising the Chesapeake for a week and I noticed water in the bilge. Managed to limp in to a dock where the mechanic said he couldn't find any. I was able to locate one at Jackson's Marine in Northeast MD. Cost was about $365.00 with a discount.

Mechanic took over 4 hours to remove the pulley from the rod. Finally got it together, but now I have some vibration due to the pulley not being replaced exactly straight. He said it would not cause any problems, but I'm not so sure.

I didn't want to hijack a thread, but am I OK?

Yeah, you're OK because the OP's issue has closure........, but always best to begin a new thread.

IMO, any vibration at all would not be good. It will wear against parts and may eventually cause an issue.

.