Does the engine water pump require any service?

rasbury

350 mercruiser, going through the manual for the regular service stuff and it has the info for changing the filters, pvc valve, all the easy stuff.  I have a bravo II out drive on my Tahoe that has the water impeller in the foot and from what I've read not the case on the bravo III in the Rinker and there is not an impeller in the foot but a water pump I assume similar to a car on the motor.....and being like a car pump not really any service to be done or is there an impeller in that pump that should be replaced?  And the coolant, should that also be replaced on some sort of schedule? I did not see anything about that in the operation manual...I don't have the service manual but there is some details of service schedules in the operation manual. It is a closed cooling system with heat exchanger 

TikiHut2

Find, download, and study the merc service manual posted in the RBOC archives. There's a wealth of info in the archives alone.

My '04 merc 350 isn't a closed cooling system so I'm not much help there. I'm nearly positive that you'll still have a raw water pump somewhere near the frt starboard side of the engine, and a separate engine circulating pump (like a typical car engine) on the frt of the motor. The raw water pump will have a rubber impeller that needs to be replaced every other year with avg use. The other one should be replaced if it ever dribbles water from the shaft (indicating a bad bearing) or if your temps are suspiciously high for no other reason. Other will chime in with more I'm sure.

There was a lengthy thread with pics on my little impeller replacement drama due to a merc mfg defect that might be a good heads up so you don't have to live through my experience. Here's the ((LINK)). The moral of the story....take your old impeller with you to the parts dealer and DON'T install it even if it's a tiny fraction of an inch off in size.

Good luck, Mike

Dream_Inn

Yes, there is still an impeller that pumps raw water thru your risors & manifolds. It is more than likely in a pump on the bottom left side of the motor (under alternator). Typically there are two hoses that come in on the back of it and two bolts on the engine as well as a bracket that may go to the alternator for removal. There are like 6 bolts on the pump that need removed to get to the impeller. Also read the post that Tiki posted.

Dream_Inn

Yes, B3s only have the pump on the engine. Ras, I still learn something each time I'm on here.

MarkB

I believe the raw water impeller should be changed every 3 years.

Dream_Inn

Ras, a little trick when installing the new impellor, use a larger wire tie to help compress the impeller into shape as you push the new one back in.  It should slide off as you get it in.

youstolemybeer

had the same happen to me, only I was drifting downstream when the belt broke and took out the fuel pump that lives on my water pump housing.   If the pump doesn't spin than either you have a chunk of the impellor jammed in the housing, OR the bearings in the pump  are shot. both are not that bad to repair.

Black_Diamond

Ras: if the belt is the correct length and type, the 'marine' and auto belt are exactly the same...except the price of course.

If the raw water pump will not turn you almost certainly have a frozen bearing and that will take out a belt pronto.  There is no sense in wasting your time or money trying to rebuild it, others will testify to this too, go new and this would be the ticket:

http://www.hardin-marine.com/p-15774-stainless-steel-gen-7-sea-pump-for-mercury-350-496-and-502-mag.aspx

Glassguy54

Our Bravo III pump went out early this season, in fact, the first time we tried to go out! Got the high temp warning alarm and the gauge indicated over 180, so got it back on the trailer and took it to the marine mechanic. They at first tried to just replace the impellor and that didn't cure the problem, so they wound up having to replace the entire pump assembly, which on the 350 MAG MPI Bravo III is rather tough to get access to. Tiki claims he can do it in about a half hour, which I find  incredible, but I paid to have ours replaced and it cost about a thousand bucks - parts & labor. Not exactly how I wanted to start the season.

TikiHut2

NOTHING like the starter. Thank God for that slave solenoid up on the engine eh?

Spray any bolts with penetrating oil the day before you start and you'll thank me later. Hope yours is a straightforward fix but at least it didn't require TowBoatUS or an angry admiral/crew....... or a busted block/engine head

My Kohler genset impeller coupling broke doing a flush on the trailer at my shop last week. I had been planning on staying on the hook numerous nights on the prior trip out but because of the oppressive heat we slipped into the Hyatt marina. It certainly would've failed on a blistering hot/humid night if we had counted on it. Lucky break for us.

Good luck. That raw water pump is really pretty easy once you do it 5 times in a row like I had to. Hope that's not the case for you. Mike

Dream_Inn

Ras, I've been there done that, on a couple 270s.  Those little air hoses, you can squeeze them and then they will come off.  Took me a couple times before I learned that one.  BTW, you can use the little pump thingy and it will allow you to pump out the salt water when you are done for the day (or for us northerners, we use it to pump out water for winter).  Note if you do that, there is a little relief valve to pull when done pumping as well.

As far as the pump/impeller, you are better off removing the back two hoses and taking the entire pump off.  You only need to remove the bracket that goes up to the alternator, not the alternator.  The hoses are a bit of a pain (note that one hose is larger than the other), but lube them before putting back on and they will go right on and off next time.  If you have a red hose coming off the pump, you can use go follow it towards aft and use a little metal clip and take that 3 ft section hose with the pump (I think your boat may be too old, but not sure...started doing that around 2005 I think).  Also, you can use a wire tie around the new impeller when installing to help.

Cableguy Greg

Closed cooled, it would be coolant. Sea water cooled, rusty water.

TikiHut2

Just got caught up on the latest story line. I feel your pain. For me it was the funky impellers with the mfg defects helping me gain a more intimate understanding of the twisted shoulder/stabbing sharp pokey thangs everywhere. In/out 4 or 5 times for ONE replacement that worked. The upside is that I got REALLY fast at it. NOT a skill-set I really needed. Think Karate Kid...... Mr Miogi, Wax-on, wax-off. repeat until you accept the drill for some unknown skill you'll need in the future.

Definitely easiest to completely remove the whole pump at all costs.....except don't cut any hoses no matter how frustrated you get. Get those batteries outta the way too. Hey, hang in there and no short cuts.
Mike

rasbury

so there is nothing in the foot then? It's 100% through that raw water pump? I found the manual Tiki...I assume it will cover a 2005 as it does not say a year on the cover anyway....I sure am glad I found this forum!

rasbury

10-4, thanks...I went ahead and got a pump kit as I have no idea if it's ever been changed so I'm doing that this week. Thanks!

rasbury

10-4, nothing like taking advantage of the tricks learned before you try it!

rasbury

well, never got this done and caught up to me unless it was a bearing that went. First really nice day in a month and the official start of boating season in central Fl. Anyway, started it up and got it off the trailer and went on doing other things and the hot water alarm went off, belt was broke. Got a new belt (bought one at an "auto parts" store, same quality?) and the raw water pump is frozen up, I have searched posts for repair and know of the maintenance with changing the impeller, what about a pump that won't turn? Is this pieces of the impeller jamming it up? At least it happened right at the dock!

Dream_Inn

Ras, I don't know the year of your boat, but if it is anywhere close to 10 yrs old, you should just replace the entire water pump (they come with a new impeller installed.  & go with the hardin one mentioned.  I've seen more boats right at that 10 year mark where the pumps just start to leak and cause issues (had it happen on my previous boat - both engines- a buddies this weekend, and 3 other dock neighbors last year...all ~10 yr old boats).

rasbury

that's about where I'm at so I'm right on trac then, I hate to be late for anything!

rasbury

I will bring the boat home in a few days and pull it off, who knows, might be lucky. Motor has like 100 hours on it....

TikiHut2

Well, this is an old thread but here we go again.

I had posted pics and details/tips on replacing the raw water pump last year on our '04 5.7 merc. (links above in my post last year) I pulled mine 3 or 4 times before it went right due to a rash of impeller recall issues. Be aware of the fractionally small change in size of the old/defective impellers /vs/new. A 1/16" makes all the difference between frustration and success.

A new complete pump assembly is upwards of $450. If the bearings ok and money's tight you can get a new impeller, but also get a stainless backing plate kit sold on ebay if the housing is scored even slightly. Take a picture of the belt routing as mine was NOT installed like the handy decal on the thermostat housing.

Good luck. Mike

rasbury

yep Tiki, I did see that before and the troubles you went through.....I decided not to work on the boat yesterday and put it up in storage and enjoy the stunning day we had yesterday, at least it crapped out at the dock. I will bring it home later this week after I see what the schedule looks like, looks like a bit of a pain to get to but still better than that darn starter! 

rasbury

well, this sure has been an adventure and not yet done. First, my pump is nothing like the one in the manual or all the pictures I see on google images. I was able to get the pump apart on the motor, just can't get enough fingers in there to put it back together. I have posted some pictures, but, to get it apart, there are six 10mm bolts on the backside of the pulley side I have in my hand. The impeller is all mounted in that pulley side and once you get those 10mm out, it pretty much is there in your hand. Two of the veins were torn off and they jambed the rest of the works. Once the old impeller was removed, it turns freely so I put the new impeller in. I used some vasiline to hold that darn 'O" ring in place, got it mated back together and one screw started but the whole thing tuned, "O" ring comes off and oh crap. By the way, my pump housing appears to be brass and I see no unusual wear inside the housing. So, I tried to repeat the partial success and gave up, now seeing how much crap to take off so I can get to it better.  Now mine also is fresh water cooled so I have what appear to be a couple of air or pressure lines on the "engine" side of the pump, about 1/16" or so in diameter going up to the heat exchanger so have a few extra things going on. Anyway, quits for the day before I grab my hammer to "fix" things. If the genny where not there I'd have plenty of room to get down there I think. I pulled the alternator and was going after the fuel water separator, fuel pump etc. to clear a path to just get the pump out but decided to call it a day. Maybe if I pull the batteries out that will give me some room to get in there on that side. For a maintenance item, sure would think they could have figured out a better place to put it as this sure is a mess to get at and change....

rasbury

I'm not sure where the pump thingy is, when the belt broke it must have sent it flying to parts unknown, probable under the motor I'd guess.....so you can hook that up to pump all the water out of the block or heat exchanger? Interested for more details on that.....

Dream_Inn

hmmm, interesting, it seems like my post disappeared, but yet you got to read it before that happened, so that's good.

As far as the pump, there should be a shrader valve on the top right side of the engine (near the gear lube reservoir) and next to it is a valve with a key-ring loop on it.  You use the little blue pump (mounted on front of engine - unless it fell off, real easy to do) to connect to shrader valve and pump.  When done, just pull the little release pin to help release pressure and the valve at the bottom of the water distribution will close.  It is that simple.

rasbury

some how on these old posts when you respond it's further up.....I gave it a shot again tonight but gave up pretty quickly so I'm back to removing crap...I also have on that side the strainer/hoses for the genny right in that corner also. I tried to pull one of the hoses off the strainer for the raw water, got the clamps off ok, that hose is not coming off with my feet up against the strainer and pulled with everything I have, it turns but not coming off. I got one of the hose clamps off the pump but if I can't get the other one off I can get to, can't imagine getting those hoses off without cutting them off and I'm guessing that's not the way to go. Extremely frustrated that such a simple routine regular maintenance would be such a mess. have the alternator off and guess I will pull the fuel pump and all those brackets, then I can probably get the genney strainer out of the way to get to the pump. This is ridiculous but have peaked at other boats where it would be worse but geesh!

rasbury

and the pump will remove water from the heat exchanger? Where does it pump it out to? I thought the raw water system would drain out but I guess it won't drain past the water pump...hmmmmm

Lifes Good

Is the pump above the waterline?

Dream_Inn

The seawater pump is generally not above the water line.  You usually need to raise the incoming hose a little so water does not come in.

The little handwater pump should remove water from the heat exchanger as well.  It just works under pressure thru the system.  It pumps out in the bottom front right corner of the engine.  I'm trying to remember exactly (I just did it this past Saturday), but it's near the multi-drain area.

Ras, don't give up on those hoses.  I've had some just as bad, but I've used leverage of the engine and rotate it up as I pulled. Once you get them off, the next time around is a very simple.  Some reason the first time, those hoses just mend themselves to the fittings.  Make sure you lubricate the inside of the hoses before putting back on.

rasbury

so dream you have to open something then for this to pump the water out?? My boat is out of the water...or I probably would have just pulled the plug on it and called my insurance company at this point...I'm going to have to remove the fuel pump, water seperator. Once I have that out of the way, I think I will then be able to get the filter basket for the genny removed and move that to the front wall and then I actually should be able to get the pump back together without removing the hoses from the back. I can ALMOST do it as it but I'm concerned the O ring may come out of position and will have to start all over. My pump is the big brass one, the impeller is actually on the front side of the pump and not the back so it that sense, a little more easy to service. I hope when I relocate the basket for the geny that in the future I can get to it to service it without all this. I still am disapointed that such an item that needs to be serviced regularly is so hard to get at, can't imagine what I would have been charged to do this. Guess that's why the last time I was at the shop where I store my boat, he had 4 boats he was putting new motors in, to dang hard to service unless you don't have money to put new motors in like me! I will win this battle! I assume all these hoses last for a while but if I start yanking on them I'm also concerned it will lead to them failing.......

rasbury

on those fuel lines, is there any type of sealant that needs to be put on those fittings when I reasemble???

jbounce3

Well,  like many of you,  I found some small traces of  rusty water in the bilge. Yep, it was the water pump.  I became suspicious when there were salt deposits on the alternator and the riser paint peeled off.  I think a replacement every three years is a great idea. fortunately, no collateral damage.  

rasbury

jbounce- which pump? Do you have a fresh water cooled or just the raw water? Not sure why any water from either pump would be rusty.....