On my 410 I remove the fiberglass section of exhaust pipe to do any work down low on that side. Takes a couple of hours to change that one.

 

On a 450DA, there should be room to crawl to the back side of the stbd engine by slowly and carefully crawling over the transmission. Once you bet back there you can squat/lay along the back side of the engine and the seawater pump is pretty easy to get to. Going around the rear of the engine and over t he water heater is much more difficult. If you have trouble doing it the way I suggest, then get used to the $200 cost because there isn't any other way.

Removing the entire pump isn't very efficient because it bolts to the engine's accessory drive and is gear driven off the engine's front end gearing. You still have to get to the back of the engine to get to the pump bolts and to realign the gear teeth when you reinstall the pump.

 

Thanks for the info. That's appears the only way to get to it, i.e., over the transmission from the fwd part of the engine room. I still have to lay across the water heater and work thru that very limited space between exhaust pipes. HUMPH, how difficult is it to remove the section of exhaust pipe? I've thought about that but never tried it. Guess if Frank doesn't know a way, there ain't one. $200 isn't a lot in boat dollars.

 

Ive owned my 450 since 1997 so I've done several impeller changes. If there is a trick to this it is to be prepared when you climb behind the engine. Have your wrenches, rachet, extensions, sockets, screwdrivers, puller, new parts, etc. ready and laying on the aftercooler cover so you are ready when you get in position and so you only have to make one trip to never, never land. As far as removing parts of the exhaust system is concerned, changing the impeller is about a 10 minute job. I'm not a fan of doing 30 minutes work to accomplish a 10 min job unless it is absolutely the only way. While not the most comfortable position to be in, squatting behind the engine and leaning over to get to the water pump is favorable to making a long term project out of removing the exhaust system.

The one I am not looking forward to at all is changing out the water heater.....................

 

On the 410s, the stbd exhaust (long fiberglass section) has to come out to access the pump. Not hard, just takes about a half hour the first time. Additionally, for both pumps (on the 410s), a fuel line (from the fuel cololer) and the oil pressure sender have to be removed... Not sure about that on the 450...

 

Great design on that right? Once you understand what to remove before you start, it's not too bad...

 

Fortunately my mechanic is a little bloke who makes the difficult jobs look simple. He also has the patience of a saint...whereas i am deficient in this area.

 

Thanks for your replies. I'm just going to get out my checkbook and call the mechanic. I'll down there in front of the engine pulling the cover off the heat exchanger to recover the always missing vanes, so I can pass him tools.

 

I am having a very difficult time just with basic impeller removal on my 3126. I am currently working on the easily accessible one. I have the cover off with 3 bolts. Next I tried using the large bolt threaded into the shaft opening but after I get it maybe 1/4" out it just seizes up. The bolt just won't turn anymore. I tried tapping it a bit with no effect. IT was suggested to me to turn the engine over just briefly but that didn't do anything either.

Any suggestions at this point would be appreciated.

Thanks

Dave

 

It sounds like you have the wrong thread on the extraction bolt; I believe it is 3/4-16.

 

Spray some WD40 or other lubricant into the pump body. Bump the engine over (get the key slot as close to top position as possible before pulling impeller). With the lubricant the impeller should slide out pretty easily. As mentioned above, you need to remove the oil pressure sender and pivot the fuel line connection in to the fuel cooler (shouldn't need to remove this) to gain clearance. I pull the fuel solenoids as I do this when the boat is blocked and don't want the engines to fire when I bump them.
When installing I use a zip tie to compress the lead end of the impeller then use a silicone lubricant (generously). They slide in by hand, but don't get them too far in until you have the key-way lined up and the key inserted.
Easy on the port side. Stbd side is the same routine...just not a great working position. I change them every year and hate the job less each time.
Good luck!

 

Ahhh, impeller on the starboard, I've spent a few hours on the outside of the engine. I got stuck back there once. bring your cell phone.

 

Me too Turtle - especially when you get a charlie horse down there - I don't know whether to laugh or yell for help!!!

 

Do you pull your exhaust pipe to get down there? I do and I pulled the aluminum hatch brace when I replaced the pump itself. Gave me much more room.

 

I'm going to need a video if somebody does it without pulling the pipe.

 

I've had it done every year without pulling the exhaust or the oil pressure sender (takes the right length puller bolt). It's tedious work, but it seems like pulling the exhaust would be a time consuming messy job. Solved the problem this year. Since the Cat guy was coming to reset my overheads and recommended rebuilding the sea water pumps, I had him put a new pump on the stbd side and rebuild the port.

 

Ken - did you put the silicone back on or just leave it off?

 

I like to pull that beam and engine exhaust to get to the generator's raw water pump but don't really need to for the Stbd engine's; just the exhaust for the engine's impeller. But I usually like to do both as well as the generator's fuel filter when I need to get in there.
Rather than bedding the beam in sealant I use EPDM foam rubber; water seems to stay out just fine and can easily remove the beam any time. http://www.mcmaster.com/#standard-foam-sheets/=125tjcb

 

All I did was cut through the silicone with a razor knife. It's still there but will not seal it very well. I like the idea of the pad that ttmott mentioned. I may need to look into that! The only real water I get in the cockpit is from my hose since I have full canvas with wall to wall Infinity Carpet.

 

Hmmmm I thought that I tried to put the extraction bolt in the new impeller to test but maybe not. Can you confirm that there are no other bolts to remove other than the 3 for the cover (no set bolts or retainer bolts on the impeller case for instance)? And you don't have to remove the pump from the engine first?

thanks

Dave

 

Confirmed, no other fasteners. Sometimes if the impellers sit they will stick a bit. put a wrench on the bolt and crank it out.

 

I bumped the engines so the were definitely freed up and further dumped some wd40 into the vanes to no avail. I only tried the easy stbd unit. Maybe this weekend I will try the port.

The bolt definitely ground down and would not turn further. It is hard to believe that the threads were wrong. It definitely felt like it was threading properly. The first couple of threads on the extraction bolt actually disintegrated a bit.

dave

 

I think also you have a problem. It should have slid right out. Agree, need to pull the pump out. Pump is a Sherwood P1732C and is held on the engine with two bolts; one of the bolts is through to the front cover with a nut. If the pump drive shaft is boogered up you may have to consider a major repair kit or new pump. Here is the Depco Catalog, look on page 114. http://www.depcopump.com/catalogs.php

 

David - definitely try your bolt in a new impeller. My extraction bolt has a "T" handle and it screws right in and with just hand turning, pulls it out...

 

Carter your description of the t handle tells me how easy it should be. I am starting to wonder if the key has somehow jammed in the impeller.

thanks

Dave

 

Dave, If that's the case, you may want to remove the entire pump and work on it on a bench...

 

David - you might try tapping it with a hammer to see if that will break it loose. Try to tap it on the end of the impeller and maybe there would be enough movement into the housing to break it loose.

 

I did mine last summer after threading bolt I bumped with the racket and she came right out??