Changing Raw Water Pump Impeller on 32+2 CB with Cummins 6BT

[Doug]

I know I have seen this subject addressed before, but am not able to locate the post.
I need to (for the first time) change the Raw Water Pump Impeller on our 32+2, which has a 370 HP Cummins 6BTA engine.

This pump looks to be very difficut to change, so I need some advice. I have a complete rebuilt spare pump, and it looks to me like it might be easier to change the entire pump rather than install a new impeller while leaving the pump in place.

Here are my questions:
1) Is it easier to remove the 4 small bolts that attach the pump to the plate that attaches to the engine, or is it easier to replace the 2 larger bolts on the plate that goes onto the engine? Do I need to remove the nut that is on top of the engine mount?

2) How do you get to the lower bolts?

3) Is it necessary to remove the 2 fuel hoses in front the pump before doing this.

4) When removing the pump. should I remove the upper and lower hoses from the flanges or it is better to remove the 4 bolts that hold each of the flanges to the pump?

5) What else do I need to know to accomplish this job.

I am posting these questions in both the Command Bridge 32 -45 section and the maintenance sections, because I do not know which is the better location to post.
Thanks in advance
Doug

[jleonard]

I had this engine in my old Mainship 34. The first time I changed just the impeller by removing only the rear cover. I remember having to first disconnect the fuel cooler to be able to have good access. Of course I dropped the key into the water intake hose and it took some time to retrieve it.
The second time I replaced the entire pump. I knew I could NOT remove the bolts with the engine mount stud in the way....so I jacked up (supported) the front of the engine and removed the engine mount via the 3 bolts into the block. (this insured my alignment would not change). Then I removed the pump via the 2 large bolts on the football shaped flange. This sounds like a long process but it was actually only a couple of hours. In actuality not much longer than changing only the impeller.

[Pitou]

Things are probably different in the bilge of the 32+2. In my 28 I found changing the impellar not anymore difficult than most projects around and below the engine. What I do recall is turning into a pretzel and working by braille to get the key back into the keyway which I had initially dropped the key deep down in the bilge which then required a ride home to grab the magnetic snake to retrieve. The cover plate has 3 cap screws and voila .... the impellar is exposed. All told 1 1/2 hours plus or minus and per usual when working by braille ... a couple of scraped knuckles and a language issue! This project is definately a test of one's own patience. Best of luck, whichever way you choose.

Here is link to a previous discussion: http://albinowners.net/aog/viewtopic.ph ... t=impellar

[RobS]

Tony Athens Seamax seawater pumps on Boatdiesel seem to be a good upgrade investment as it eliminates the "key" and the interference issue with the front mount. I don't have a 6BT but I think I read everything on that site over the last year, regardless of whether or not it directly applied to me.....knowledge is a good thing.....

[Veebyes2]

Ah, one of the great joys of owning an Albin 32!!!

Answer is, there is no easy way. The more space you make for yourself the better. Nothing will happen till you draw first blood.

I've done mine both ways, pump on & off the engine. It is easier overall to remove the pump & deal with the impeller on the bench. The last time I changed the impeller it looked like this.



Believe it or not the engine was still maintaining normal operating temp at low speeds.

Wish I could give the step 1,2,3s of how to do it but it depends on the tools you have, & your skills & patience.

[Russell]

On the 250 hp it is a lot easier and after the first time it takes only about 20 min to change the impeller. The hardest thing is dealing with the bolt nearest the engine block because there is room to swing the wrench only about a quarter turn. Luckily the first time I did it the key was frozen in the keyway or it would have been in the bilge as the impeller comes off with the cap.

[TD]

I have twin Cummins 6B's in my 2000 TE 35 and changed the impellers this last spring. The only thing I did first was shut off the seawater intake then take the cover plate off the pump. The impeller has about 4 threads that you can screw in a bolt for better removal grip. I believe the bolt was a 3/4 inch coarse thread, but if you need the exact info I can get it for you. You do have to be carefull and retrieve the key before it drops somewhere that it shouldn't, including internal to the pump housing. I lubed the new impeller up with vaseline and slid it in, lined it up on the key first, then slid in the key. My port engine was the tightest and had to work mostly with one hand but I took my time, got as comfortable as I could and went to work. It took me a little over an hour. I didn't have any impeller pieces missing, but if you do, you should at least flush backward and forward the seawater system to get any chunks out. Good luck.

[Doug]

Because I had a spare pump, I decided to replace the entire pump rather than just the impeller. It is a good thing I did, as Depco (the pump repair facility) found many other parts of the pump that needed rebuilding. The following is a list of what we did in order to change the pump.

Shut off Raw Water Intake
Shut off Fuel Supply
Remove Throttle cable
Remove 3 fuel hoses and plug with small rubber stoppers
Use small bottle jack and jack up Starboard side of engine slightly
Remove entire motor mount on Starboard. This takes a 1 1/8” wrench plus
other wrenches
Remove Raw Water Intake hose on bottom side of pump
Remove 4 bolts on flange at top of pump
Remove top and bottom bolts on Water Pump (a “shorty” 15mm ratcheting box end wrench is very helpful).
Once pump is off, either rebuild pump or install your spare pump.

Note. We had to grind off a small part of the edge of the football part that goes on to the engine in order to remove the double nuts on top of the motor mount.

When re-installing the motor mount, set is as far away from engine as possible in order for top motor mount nuts to clear pump.

Total time (2 people – first time doing this) approximately 2.5 hours to get off and about the same amount of time to re-install pump.

Thanks to all of you for your suggestions. This is not a project I would want to tackle while away from my home port.
Doug

[TD]

WOW!! The 32 is obviously a much different situation than the 35 ft. The 35 post would be not be of much help to you since access is so much different. It is good you could do it as I wouldn't even want to guess what a shop would want. Congradulations on your great accomplishment.
Terry