Raw water pump replace/maintenance
 

Doing some maintenance on the motor and was dreading replacing the impeller in the raw water pump. I've removed the exhaust manifold to do some other work so I have more room but not much. Have been looking into the Hardin pump (they sure are proud of them) but this doesn't help me in the replacement task, just allows for the bolts to be tightened more without cracking the housing. Need to get it more accessible but there is no room on the crankshaft and some room in front of the circulating water pump.

Was looking at the camshaft pumps which wondered if something like this could work. Maybe move the ALT, PS or something else to move the water pump to the port side would help.

http://forums.iboats.com/filedata/fe...7252&type=full

I could be wrong since ive never paid attention to it before...but i don't think i've ever seen a camshaft mounted seawater pump on a newer EFI motor before. :confused: Since you say you dont have the room on the crankshaft to mount one... then i would see if you can fabricate an adapter to mount it to the water circulation pump...just have to make sure the circulation pump pulley spins at the proper speed or it wont turn the seawater pump fast enough and you wont get proper cooling....that would probably be the easiest and cheapest way out of it....going to a camshaft mount would require you to find a new timing cover with the adapter for the cam and you would need to get rid of the circulation pump and get some sort of crossover...then you would have to re-arrange the belt to clear everything etc....

I'm sure your correct, just looking for something to make this easier. Removing items and hanging upside down for an hour just isn't fun

you sure don,t have much room in front of the engines,i can see why you are dreading the job.i added the hardin ss bodies to my pumps this year because they should never need to be replaced,i just don,t like the idea of a plastic housing that will get weak and brittle after enough heat cycles.i remember changing one on a 95 degree day in the sun,that sucked.

I'll go with the hardin if some other idea doesn't show up. Added it to my cart and was checking out then found they wanted another 26 just to ship. That was a give me a break moment, it doesn't cost that much. As before I'll probably go back and get it, when you have something good you can charge what you want

Need to get a halo drive shower also, and that to is give me a break, 200 for a piece of tubing

This Harden cap is nice, ran them on my bravo's, easy install, comes with 12 point stainless hardware and bolt right over the exiting top cap. As far as changing the sea pump ?? a trap door in the hull looks tike the best option

Edit: I think their about 125 each

I recently went the Hardin route. Very, very nice piece. Very, very pricey piece! I got 10 bucks off by entering "save10off100" in the promo code field at checkout. See if that still works. Every little bit helps.

Was trying to stay away from drilling but since I'm in fresh and just installed a lift, the holes shouldn't be that much of a corrosion issue any longer. Do like the looks of it as well

Thanks for the tip, it might help, and I would love to have that much room to work in.

How much are those Hardin pumps?

The entire Gen 4 pump is 340, the rear housing is 190 and you need 2 fittings at 25 each

less than one weekend of gas&beer!

Worth every penny of the gas & beer, not so sure about the pump.

Bob possible install what Volvo Penta set ups Merc locations can be very hard to work on and to see water leaks when they take place. Volvo Impeller housings have less problems than OEM Merc stock gen IV pumps. Just saying.

http://www.volvopenta.com/VOLVOPENTA...es/V8-430.aspx

http://www.volvopenta.com/volvopenta...ginerange.aspx

Volvo's other locations possible using the correct brackets and correct belt(s).

Folks, Im getting the courage up to tackle the impeller change on my 2007 525efi x 2. Impellers were replaced, Aug 2014, 43 hours on engines since then. Fresh water only, stored indoors, no exhaust flow or temp issues, but dont want to wait for those signs, too late then. Suppose I am overdue on this job as it stands! I have seen the video out there that outlines the process, which looks doable. My questions:

Hands down, do I need to remove the water pump assembly to do the job?

What are the torque ratings for the housing bolts as well as for the bolts onto the engine bracket?

Thanks,

I'd be cautious when tightening the two hose clamps on the supply and intake hoses. Very easy to crack the impeller housing.

ah, good point. tight enough to keep the hose on, if leaking, can tighten a tad more, dont over tighten...Thx.

I put on a brand new pump kit at the beginning of last season and heard the dreaded "crack" of the plastic housing and its such an awkward access that I couldn't really feel how hard I was torquing. I would've paid $500 for a water pump at that point.

Have the dry-run impellers improved any? Reviews on them are like bravo drives - they either last 5 minutes or 5 years.

The plastic housing bolts just need to be snugged up. Have not done a 525 but a lot of other motors.

The run dry seem to do well on Alpha drives, but not so good on bravo's and such. For me its still every two but have let it go three

Still using the plastic housing on my Rinker (way easy to get at), but bought the Hardin pump for the Formula

Merc black plastic housings always use the new wear plate and the 2 new O ring gaskets - one small round and the other bigger O ring on the front side of housing (lip)

Tightening is 10 ft lbs max in a star tightening pattern and I like to use the 3 pass rule for tightening. Always makes sense to me.

Thanks all. Always new wear plate? Even if no sand or silt (next to no silt I suppose, limestone bottom lake)?

I found the small quad ring, but the larger one for the housing doesn't seem to be available solo. Anyone got a P/N or source for it?

Its 25-841807

I always replace the quad ring but have yet to replace the O-ring, and have yet to have a leak. Not saying it's not a good idea to replace but I'm in fresh water and never use oil or other on the ring

Its best to buy the kit - comes with even new bolts. Its like 50 bucks more compared to just buying impeller alone. Kit is housing, impeller, wear plate, bolts, 2 - O rings. On Merc kits the o ring is already installed on the new black housing. Sierra kits do not install the new oring on the black housing.

Just buy the kits you are way better off - cost is under 100 bucks per kit.

Wonderful, thanks guys! Appreciate the info and wisdom

WOW Whoever designed that engine compartment should be ***** Slapped. Or better yet they should have to come change the pump and then get ***** slapped so they don't ever design anything like that again.

Chris

I have a brand new never used Hardin Marine gen 4 stainless sea pump with plastic housing. 200 plus shipping Mark 765-425-6912

Has anyone done the job without taking the entire water pump off the engine? Can I take the bolts out that hold the housing, holding water pump and inserting a bolt back in to bracket to hold things together or will the tension from the serp belt kabosh the job?

You can do it without removing but you must get the tension off the belt. By the time you have the housing off there is nothing holding the pump

ya, a bit tricky with just the fuel lines attached. I would tie off the pump so it doesnt drop, then quickly get a bolt back in place to hold it... Is it messy to pull the rubber hose, the metal fuel line, and then the breather hose?

Well, quick update on the project, only took an hour and had the impeller and housing in my hands with the pump still affixed.

Removed serpentine belt from pulley, secured the seawater pump with tight bungee cords to be sure it didn't drop, backed the 5 bolts out, cradled it, then put a couple of the studs back in place to attach it back onto the bracket. 2yrs 7mos old with 43 hours of run time, the inner housing has some scratches and the impeller some scrapes in the fingers, but largely all in great shape. Prefer to see and know it was/is fine, then not know and have one shred apart on July 4 weekend or something!

With it off now, I will get the kit and start with a fresh set up this season.

Thanks all for the comments and information.

Maybe one more question, some lube on the impeller to get it in place?
Thin layer of Ivory soap on the tops of the impeller blades to get it properly seated in the housing? I think I read somewhere that was the recommendation.

Thx.

Soap is good, don't use oil or grease. You can use WD40 because after it dissipates what is left behind hurts nothing. I use soap, some use glycerin

Some info to think about --- Impellers are a form of rubber compounds - in which is derived from oil - dish soaps and soaps clean oils away and dissolves oil very well - one good example when crude oil was dump in the ocean and the animals were covered in crude - many of those animals were cleaned with Dawn soap because it cleaned away and dissolved the crude oil very well - . Anyways the product for installing impellers from those manufacturers, one example like Johnson Impellers is glycerin. Or water base KY jelly - FWIW

You can buy Glycerin at most drug stores

What type of rubber are impellers made of ?

Just learned something new! Thanks, I will steer clear of the soaps and follow your expert advice, thanks!

Steal the KY from the night stand ....

Wonder how many folks install an impeller and put it to bed for the winter. Don't see soap doing anything to rubber, if it did I'm sure there would be threads over the years of impellers and exhaust boots being damaged. Impellers will wash everything out, the boot will not.

Mercury manual states to lubricate the impeller with a water and soap solution.

I've done at least 50-75 with dish soap