Raw water pump impeller install 6.2L v-drives

AAK

Member
TECHNICAL Contributor
Feb 14, 2009
135
Perry Hall , Md
Boat Info
2000 38 Sundancer
Engines
7.4 Horizon FWC
RAW WATER PUMP IMPELLER INSTALL

I put this right up on the 320 thread but I thought it might help to also place it in the maintenace section too.

Let me start out by saying I’ve been doing a lot of work on my boats for years and this is the first time I’ve done the newer style water pump impeller replacement on the fuel injected engines. I’ve done a bunch of the old style pumps on the old carburetor equipped motors before. By no means am I saying this is the only way to do the job; in other words I’m not a mechanic or an authority. The reason I’m putting this out on the site is that I had asked about some quick tips for doing this on the site and never got a complete answer on start to finish. I know, maybe I didn’t search the site long enough for this information. With that being said enjoy my painful tale about spending the weekend in the bilge of my 2006 Sea Ray 320 with 6.2L v-drives.

Access is the first thing to address to do this job. I’ve done them before (the old style pumps) by laying on the motor reaching down but the wonderful fuel coolers block your access from the top. I decided to remove the port muffler (drain it first since I ran antifreeze through my motors when winterizing), both hoses from the risers and the large hose going to the thru hull exhaust from the muffler. A helpful tool to use on the hose clamps is a 5/16” socket to stay on the clamps when you turn them. I also removed the inboard exhaust hose on the starboard motor from the riser to the muffler. It took about 45 minutes to remove all of these items. This positively was the right thing to do for the required access. The reason I did the port side removal was to also gain access to the starboard water pump that is close to the port side engine.

I started with the port WP and decided to remove the pump with the bracket since a few people had said it would be tight but you could do it even if you had to grind a little on the pump bracket and housing. Long story short is don’t do it this way; you’ll see why as the saga continues. First step is to remove the serpentine belt. That requires a 16 MM wrench to loosen the nut on the belt tensioner. I then took the two blue drain plugs out of the pump body to reduce any potential vacuum when removing the hoses. I loosened both hose clamps and pulled the hoses off. You might need to use a flat screw driver to get on the edge of the hoses to free them up. I then took the lower bolt out of the WP bracket with a 14MM socket. Next I removed the nut from the stud of the top of the WP bracket with the same 14 MM deep socket. As I pulled the WP forward it would not clear the harmonic balancer and fuel cooler unit. There is a small piece of casting on the back side of the WP bracket that hits the harmonic balancer. I got a die grinder and removed some metal off of the WP and bracket. It still would not come out. I thought about removing the fuel cooler but this is a waste of time for a couple of reasons. It is mounted on two metal brackets. The front bracket would come off easy; there are two 10MM bolts on the front holding the fuel cooler on and one 14 MM bolt at the engine for this bracket. The rear bracket is next to impossible to access. I decided to remove the front two 10MM bolts at the front bracket and push on the fuel cooler. Under much strain and pain it moved enough to let the WP and bracket come out. Believe me this is not the way to do it. I got it back to the bench and removed all of the 10MM bolts and removed and replaced the impeller and o-ring. The Merc part number is 47-862232A 2 for this kit that includes the impeller and o-ring. My impeller was cracked so the job was needed. I was able to remove the impeller with needle nose pliers; I know they make a tool to do this but I’ve never needed it. I also choose to use petroleum jelly to lube and protect the impeller on the initial start up. This also helps it to slide in the housing. You can also use dish detergent but I don’t plan on starting the motors for another month and I’m not sure the detergent would be a good idea sitting for this period of time. I reassembled the pump, touched up the black paint, and re-installed the two blue drain plugs with the o-rings on them. I re-installed the pump on the motor. You can also put a little dish detergent on the hoses to help them slide back on the WP. You will also notice the hoses are different diameters so you won’t mess that up. I put the serpentine belt back on and adjusted the belt tension. The way to tighten the tensioner is to first put a box end 16 MM wrench on the nut and then use an 8 MM socket on the shaft of the tensioner. I think it is a clockwise turn with the 8 MM socket to tighten the belt and then snug it tight with the 16 MM nut.

Now on to some more pain with the starboard WP. This is where the learning curve pays off. This time I decided to remove the three 10 MM bolts that hold the WP to the bracket. I first removed the 14 MM WP bracket bolt and then the nut on the stud. This allows the WP to pivot on the stud to get some access to the two 10 MM bolts on the backside of the bracket that secure the WP. The top 10 MM WP bracket bolt is easy to access. After these bolts are removed, let the WP lay on the hull so that you can get access to remove the two hoses. Use the same process on the bench for the impeller install. Now for the re-install of the WP to the bracket on the engine. I tried it two ways and one way worked. I first tried to put the hoses on the WP and install it to the WP bracket. No go on this effort since you are fighting the hoses and the weight. I took the hoses back off and put the WP on the bracket and then installed the hoses. See the serpentine belt install as listed above.

As if this wasn’t enough pain for the weekend, I went on to replace the impeller on the Kohler 5E generator. This was an easy job as long as you leave one of the four 11 MM bolts on the cover assembly (4 total). My exhaust muffler was in the way and required one of the bolts to stay in the pump anyway. This is a good thing since the WP housing could slide off of the shaft. I installed the new impeller and o-ring with some petroleum jelly. My impeller was missing one blade so I took the raw water hose off of the heat exchanger and found the missing blade. The Kohler part number is 359978 for the impeller and o-ring.

Required tools: 5/16”, 8 MM, 10 MM, 11 MM (for generator), 14 MM, 16MM – sockets and wrenches. flat and phillips tipped screw drivers, and lots of band aids. One last item not to forget- a large hammer is required for the completion of this job. Use the hammer to knock yourself unconscious to avoid the pain signals you are getting from every joint and muscle in your body.

Please guys, “no that’s not the right way to do it stuff”. This is a sincere effort on my part in trying to help anybody that has been thinking about doing this job on their own and un-familiar with what it would take from start to finish. I know everybody has a different skill level and this posting identifies what it would take to do the job. Yep, I’m sure there are many ways to do it, but this way worked for me and you can do it yourself. I was also trying to help you with the tools required to avoid what I had to do by bringing multiple metric and standard wrenches and sockets on board. I looked like a Snap on tool dealer going to the boat.

I’m sure the top question remaining is how long should it take to do this if you didn’t have to trial and error what you needed to do on this job. There are way too many variables to address the real time to complete the job due to many things. Some of the things to factor in : how long can you stand the pain without a break, how many beverage breaks, how many medical breaks for band aids, etc…….

Here would be my guess for the time involved: About 45 minutes to get the area open for access, a little less than an hour to remove the pump, about 30 minutes to rebuild the pump on the bench, and a little less than an hour to install the pump back on the motor. Figure the same amount of time to do the second motor less the time to get the area ready for access. Then you need about another 45 minutes to put the port muffler and all of the exhaust hoses you removed back on. I really think these time estimates as listed are somewhat on the conservative side and realistic.

I hope you enjoyed the write up and it will help at least one person.

Al
 
Thanks a lot Al,

This, plus Hamton's earlier description on his 8.1s, should help a lot of folks - including me. I'm going to do my stbd impeller next week. The 8.1 task sounds exactly like your description.

thanks again.
 
After you do your impeller, let me know how you made out. If you come up with anymore tips that would help on this job please post them.

Al
 
Thanks AAK. Your dedication and effort posting this material will be very beneficial to the mambers!:smt038
 
If somebody said they could do both of the impellers on a 320 with v-drives in 2 hours I would like to watch that process.

Maybe the engines were out of the boat on stands LOL.

I guess it would be interesting to have other people tell what labor hours they were billed for or how many hours it took them to do the impellers.
 
I replaced the whole pump. This is a very poor design and you description is right on the money... it's a real pain. I had volvo penta's/crusiders for years with a front mounted WP much, much beter. The merc tech that designed these Wp should be commited!!
 
I thought I would post an update. The boat has not been started since I did the install on the raw water impellers. I was able to run both motors up this past Saturday for the first time since the install. I wanted to wait to avoid anymore freezing overnight temperatures. They started right up with no pump or belt noises and I had nice streams of water coming out. It appears the install was a success. I still need to start the generator up but I'm not that worried about that install.

Let the good weather start!!!!!!!!!!!!!!
 
TopGun 1185
Did you move the cool fuel filter to get access?
I heard their was a quick release for the hoses -- rather than trying to take the two hoses off the back of the pump?
Any suggestions you have would be appreciated-- I have to do my port engine this spring.
Thanks
Rich
 
. One last item not to forget- a large hammer is required for the completion of this job. Use the hammer to knock yourself unconscious to avoid the pain signals you are getting from every joint and muscle in your body.

lol I'm facing this job this wkd. I might keep a hammer handy just for the humor.

(on second thought, I should keep the temptation of hammers away whenever working on a Mercruiser product)
 
Thanks a lot Al,

This, plus Hamton's earlier description on his 8.1s, should help a lot of folks - including me. I'm going to do my STBD impeller next week. The 8.1 task sounds exactly like your description.

Thanks again.

Al - I want to emphasize the "Thank You" - and one to Hampton also - as your two threads were a great help to me.

So why did I have to change my STBD impeller a couple of weeks ago?

Drum roll please....as the Captain is seen entering the Confessional....

As we prepared to go out three weeks ago, it was time for monthly checks, and I allowed Grant (age 13) with supervision, to clean the AC strainer - he did a good job. He also cycled the genny seacock and came out of the bilge. I asked him if he cycled the engine seacocks and he said "no", so I told him I'd get the PORT one (my stiff one) and he could get the STBD one.

Out of the bilge we come, close the hatch, and "make all preparations for getting underway" (as we said in the Navy). Crank engines, all checks are good - STBD water pressure is slightly lower than usual (.9 at idle instead of 1.2 - now you know where this is going). 3 minutes at idle to get out of the marina, engines still a little cold, so bump them to 1000 rpm - and... ALARM. Water pressure on STBD engine still at .9 and Smartcraft doesn't say what is causing the alarm, but at the same time Sue says "I smell burning rubber!". Engines OFF, alarm quits, ask Grant - "Did you open the STBD seacock after you cycled it closed?" Answer: "I'm not sure". Hatch up...stbd engine rubber exhaust hoses hot and....another drum roll please....seacock closed.

Open seacock, water pressure now normal after restart, hoses cool down and the rest of the day's cruise was fine. Water pressures matched at all rpms.

My first alarm - hopefully it will be my only alarm.

Two weeks ago we change the STBD impeller: My '05 340 with 8.1s was very similar to your '06 320 with 6.2s.

Here were the differences:

-I did not have to move the water lift muffler.
-I do not have the Gen III cool fuel unit, so there was no interference there
-There was no interference with the pump and the bracket.
-The hoses were hard to get off, but Grant can easily get in between the engines, and with him pulling forward, and me pulling aft and up on the pump, the bottom one came off first. The we could wiggle the pump up and down and get the top hose off.

30 minutes getting the pump off. Same tools Al - Thanks

15 minutes on the dock to change the impeller.

30 minutes to get it back in.

The dealer did a 200 hour check at 147 hours 15 months ago and installed new impellers. This one looked good when it came out - even after the ~3-4 minutes at idle with the closed seacock. I didn't think it would have looked that good. I'll post a picture this weekend.

We'll change the PORT one next spring.

Overall, a failing grade for a professional pilot - I flunked preflight - I didn't check for water out the exhaust after start like I normally do, and I didn't further investigate the slightly lower water pressure reading after start - so I flunked after start procedures as well.

So Captain, more attention to "preflight/post start" procedures. And yes, my punishment was 4 days of Aleve twice a day for the aches and pains.

Thanks again Al and Hampton.
 
Last edited:
SeaRenity,

The fuel cooler has water lines, fuel lines, and a wiring harness on it. The brackets that hold it on the engine are next to impossible to get the fasteners out of. I had also read on another thread where somebody broke one of the fittings on the fuel cooler when trying to move it and had to buy the entire unit. Read my post again as to what I tried to do with it and why I didn't take it off.

I've never seen or heard of quick disconnect fittings on the raw water pump hoses. Quite frankly the hoses coming off and going back on the pump are relatively easy to do.

My suggestion to you is to read the thread a couple of times and I think once you look at your boat you'll agree that getting the proper access to do the job is the key.

I see that you are in Millers Island Maryland and I'm in Perry Hall about 20 minutes away. If you would like to look at my boat or me to look at your boat and have me go over it with you that's another option.



carterchapman,

Thank you for the kind words. I was hoping this write up would help at least one person and it appears that it has. I guarantee you that your helper will never make that mistake again or will you.

Al
 
So it is time to replace impellers, deciding whether a DIY project or hire it out. So my marina said the brass pumps wear grooves in them and should be replaced at the same time. How many people have seen grooves in their pumps and is there a replaceable wear plate? On my 260 - the plastic pump held up fine.
 
Thanks for this thread it was helpful when changing out my impellers. Wow getting that pump in and out is difficult. If I didn't have another handy person there this project would have been too much.
 
Thanks for the posts! I should have checked here first...I read the Mercruiser engine manual instead.
My experience is about the same except my learning curve was about 4 hours on the starboard engine on my '06 320 Sundancer V-drive.
I'd really like to talk to the engineer that put this pump at the bottom of the engine.
Happy Cruising!
 
Posting an update to AAK’s original post on how to change the impellers on a Sea Ray 320 with V-Drives. Our 320 has twin Mercruiser 350s but I think things are pretty similar for the 6.2s. A schematic of the water pump is included at the bottom of this post as a reference.

I wrote this a reminder to myself for next time and maybe some new owners will find it helpful.

Many thanks to AAK for the original posting and others on the threat whose comments helped me figure things out.

A few notes before you begin:

--Removing the port muffler seems excessive but trust me, it is not difficult (4 phillips screws) and you will appreciate the workspace it opens up.

--Also, resist the temptation to remove the bracket (#12) holding the water pump to the engine. There is a small tab on the bracket that holds it against the harmonic balancer. That tab combines with the length of the bracket stud (#15) to make removing and reinstalling the pump as one assembly near impossible. If you remove bolt #17 and nut #16, the pump will slide out a bit and provide some wiggle room to work.

--Removing the Cool Fuel Module is also not required.

Prep the work area:

1. Close the seacock.

2. Purge the system of water with the air actuated single point drain system.

3. Remove both exhaust hoses from the elbows on the port engine and the inboard hose on the starboard engine. Loosen the hose clamps more than you think you need and use a little WD40 helps loosen the hoses.

4. Remove the port muffler.

5. Loosen the tensioner pulley and remove the serpentine belt (take a picture of belt routing or only undo one side at a time).

You are now ready to open the water pump and access the impeller.

6. There are three 10mm bolts (2x #11 and #13) connecting the pump to the bracket (#12) on the engine. A small/mini 10mm box wrench is needed and bolt #11 will come out 1/4 turn at a time. A mini ratchet box wrench would make this easier. Yes, it is slow and a PITA but it is possible and only takes a few minutes.

7. The pump can rest on the hull providing more room to work.

8. Remove the 4x bolts (#10) holding the water pump halves together. There is no need to remove the water lines from the pump.

9. Take the pump housing out of the engine compartment and replace the impeller (#2) and o-ring (#3). The old impeller will come out with pliers or vice grips. You can use a zip tie to hold the new impeller blades down while you fit it in the housing. Make sure to lubricate the new impeller and pump chamber with dawn soap or Vaseline.

10. Reconnect both halves of the water pump using the 4x 10mm bolts (#10). Make sure you do not put the #10 bolts through holes for the #11 bolts that mount to the bracket. (I learned that the hard way)

11. Reconnect the reassembled water pump to the bracket. I started by hand tightening #13 then moving the pump to get both #11 screws lined up. Then I tightened them with the wrench. Again, the screw nearest the Cool Fuel Module takes time but it can be done.

12. Reinstall the serpentine belt.

13. Open the seacock.

Repeat steps 5-12 for the starboard engine.

The procedure for replacing the entire pump is not much different. Removing and reconnecting the water hoses is a little tricky. I found it easier to do with the pump in two pieces rather than as an entire unit.

Also, I had the dealer remove the pulley from the old pump and put it on the new one. Cost was 1/2 hour labor but my desire to wrestle that was pretty low that day.

I ended up doing this twice over two weekends. First time I replaced the impellers, put it all back together only to realize one water pump was scored and should be replaced. Back into the bilge I went...

The learning curve helped, but with these instructions I should be able to do both impellers in under 4 hours next time (hopefully not before 2 years!)

waterpump.gif
 

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