40 sedan bridge forum

I HAD a problem with my raw water pump on a Cummins 8.3 that I have NEVER seen discussed anywhere. I started the boat and it never started to pump water. I looked into the bilge and I had probably 5-10 gallons of water water in the containment bilge. After trying to figure out where exactly the water was coming from I decided I had to take off the aftercooler to get close enough to see it (has anyone guessed which engine by now). I removed the top aftercooler water hose and the air hose for more room to look around and search. When I got the impeller cover off I noticed the cam inside the housing was moved out of its normal position. I removed the impeller and the cam and found a the bolt that holds the cam to the housing was broken. so a $5 dollar bolt caused me approx 4-5 hours of crap work. Replacing the impeller, keyway, o ring blind with one hand was sooo much fun. I am really glad it didn't happen away from the dock.
Happy boating!
 
Njlarry said:
Generator impeller.
Anyone know best way to get access on the 400? Started on project but gave up. Drain and remove hoses? Move the whole unit?
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There’s a detailed discussion on this in the forum from some years earlier, Assuming it’s Westerbeke diesel . I recall it being said that you can loosen the rack mount without removing engine mount bolts and angle it to get behind. And that later models were easier than earlier because of position of the water pump
 
Hi, has anyone tried venting the fly bridge when the canvas is up. It gets crazy hot up there. I leave the hatch open to help. Any thoughts? Thanks, Greg
 
TotallyGross said:
I HAD a problem with my raw water pump on a Cummins 8.3 that I have NEVER seen discussed anywhere. I started the boat and it never started to pump water. I looked into the bilge and I had probably 5-10 gallons of water water in the containment bilge. After trying to figure out where exactly the water was coming from I decided I had to take off the aftercooler to get close enough to see it (has anyone guessed which engine by now). I removed the top aftercooler water hose and the air hose for more room to look around and search. When I got the impeller cover off I noticed the cam inside the housing was moved out of its normal position. I removed the impeller and the cam and found a the bolt that holds the cam to the housing was broken. so a $5 dollar bolt caused me approx 4-5 hours of crap work. Replacing the impeller, keyway, o ring blind with one hand was sooo much fun. I am really glad it didn't happen away from the dock.
Happy boating!
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Man, that is a terrible story! But I’m glad you got it all figured out.

I can also tell, based on your description, your answer to my next question: for those of you with Cummins engines, when you replace the port side impeller, do you do it one-handed and blind, like Matt did? Or do you remove the entire water pump and replace the impeller that way? Or, do you do like I usually do, and write a check?

Second question: in order to gain access to that impeller and pump, do you guys remove the salon sofa? My hatch doesn’t open all the way with the sofa there so I’m thinking the sofa needs to come out. Am I wrong?
 
scooper321 said:
Man, that is a terrible story! But I’m glad you got it all figured out.

I can also tell, based on your description, your answer to my next question: for those of you with Cummins engines, when you replace the port side impeller, do you do it one-handed and blind, like Matt did? Or do you remove the entire water pump and replace the impeller that way? Or, do you do like I usually do, and write a check?

Second question: in order to gain access to that impeller and pump, do you guys remove the salon sofa? My hatch doesn’t open all the way with the sofa there so I’m thinking the sofa needs to come out. Am I wrong?
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I usually pull the aftercooler and exhaust from the elbow to the muffler, then pull the bilge blower and go in from the backside. That's the easiest for me but takes the longest.
For over the top I pull the charge air pipe, pull the throttle arm all the way back and pull the top hose off the pump and bungie it (still attached to the fuel cooler) out of the way.
It's awkward for me, my arms and wrists bleed a lot and the last time I did it that way, my ribs were sore for 2 days from ritching around on top of the motor trying to get it done.
Never pulled the couch.
I most likely won't be doing it over the top anymore, who knows, I might not be doing it either way next time, 4 years from now I'll be 71.
 
Hi everyone. It’s been a little while since I’ve been on here (probably missed reading the last 100 pages or so - lol).

Anyway, I’m sure this has been asked recently so I apologize for asking again, but does anyone have fuel flow meters installed on their CAT 3116 boat? I know every case is different, but I’d like to get a ballpark on some consumption numbers.

I generally cruise at 2500 rpm (maybe just a tick under) and I’m doing 21-22 knots at that rpm. Curious what my fuel burn is at that speed.

thanks.
 
The Cat 3116 engines are very consistent in their fuel flow. The Cat charts are pretty accurate. Recommended cruise power is 2,200 to 2,400 RPM. At 2,400 RPM the burn is 11.3 GPH per engine. At 2,200 it is 9 GPH per engine.
 
Adding a flow meter isn’ta simple process as there needs to be a meter for total flow and also one for the excess return and then a way to calculate the difference.
 
scooper321 said:
Man, that is a terrible story! But I’m glad you got it all figured out.

I can also tell, based on your description, your answer to my next question: for those of you with Cummins engines, when you replace the port side impeller, do you do it one-handed and blind, like Matt did? Or do you remove the entire water pump and replace the impeller that way? Or, do you do like I usually do, and write a check?

Second question: in order to gain access to that impeller and pump, do you guys remove the salon sofa? My hatch doesn’t open all the way with the sofa there so I’m thinking the sofa needs to come out. Am I wrong?
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I tried taking my couch out the last time Scooper and it didn't give me any more usable room.
I deal with the bruises on my chest and cuts all over my hands. I would have wrote a check in this instance but I likely wouldn't have gotten anyone there for 5 weeks approx. I am not that patient during the season...

matt
 
TotallyGross said:
I tried taking my couch out the last time Scooper and it didn't give me any more usable room.
I deal with the bruises on my chest and cuts all over my hands. I would have wrote a check in this instance but I likely wouldn't have gotten anyone there for 5 weeks approx. I am not that patient during the season...

matt
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I’m not worried about cuts or bruises. When I did my duckbill valves, my torso came up completely black and blue like I had been in an auto accident. Lesson learned there: remove the frame around the bunk before doing it next time.

I have my stepson coming to help me this weekend. He is a marine mechanic and has done these many times. He’s also 6 foot three and thin. So I will have longer reach and experience helping me! I hope to learn something so I don’t have to utilize him too often in the future. I am now just trying to plan out the attack, hence the questions about the sofa. I think we may go the route of removing the water pump entirely and doing the impeller above ground. And while he is in town “we“ are also going to do the belts and the holding tank filter!
 
scooper321 said:
I’m not worried about cuts or bruises. When I did my duckbill valves, my torso came up completely black and blue like I had been in an auto accident. Lesson learned there: remove the frame around the bunk before doing it next time.

I have my stepson coming to help me this weekend. He is a marine mechanic and has done these many times. He’s also 6 foot three and thin. So I will have longer reach and experience helping me! I hope to learn something so I don’t have to utilize him too often in the future. I am now just trying to plan out the attack, hence the questions about the sofa. I think we may go the route of removing the water pump entirely and doing the impeller above ground. And while he is in town “we“ are also going to do the belts and the holding tank filter!
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I’ve changed the Cummins port impeller about a dozen times total on 3 different 400DBs. Marks remove the charge pipe and push throttle forward method is all Ive ever used. Goes quick for me but I’m in practice. Half have been Sherwood pumps and half smx pumps. For Sherwood pump I had the screw tool with the handle most of the time. A couple times I didn’t and used sturdy needle nose pliers to grab a blade right at its base. First I soaked it pretty good with wd40 or PB Blaster. The key is the real detail here. Make sure not to drop it into pump. Best to have pump with key at top to minimize this. Removing the pump method eliminates that risk.

I’m 5’ 10”. 170 lbs. you gotta be good working with just your right hand should you give this a try. Don’t remove the bottom cover bolt. Loosen it so the plate falls down out of the way but is still bolted on. Use grease on the o-ring to hold the o-ring in place when you rotate the plate back up to put the other two bolts back in.
 
The SMX pumps make that job a bunch easier no matter which way you go. Silicone paste (grease) helps a lot too.
 
Njlarry said:
Cwert and other CAT capts, what props are you turning? I only get 19 knts at 2400 rpm with 22x24. Wot at the dock is 3100 but only 2600 underway.
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Larry,
I had the 22 x 24 props on the boat. Got similar to what you are seeing but slightly better. Was 2650/2720 WOT underway.

Got new 22 x 23 props and now I get 3100/2800 WOT. On a rare, very smooth day on Lake Michigan, I got 29.5 MPH at full throttle and 23.5 MPH at 2400 rpm. They are noticeably smoother and quieter also.
 
ZZ13 said:
I’ve changed the Cummins port impeller about a dozen times total on 3 different 400DBs. Marks remove the charge pipe and push throttle forward method is all Ive ever used. Goes quick for me but I’m in practice. Half have been Sherwood pumps and half smx pumps. For Sherwood pump I had the screw tool with the handle most of the time. A couple times I didn’t and used sturdy needle nose pliers to grab a blade right at its base. First I soaked it pretty good with wd40 or PB Blaster. The key is the real detail here. Make sure not to drop it into pump. Best to have pump with key at top to minimize this. Removing the pump method eliminates that risk.

I’m 5’ 10”. 170 lbs. you gotta be good working with just your right hand should you give this a try. Don’t remove the bottom cover bolt. Loosen it so the plate falls down out of the way but is still bolted on. Use grease on the o-ring to hold the o-ring in place when you rotate the plate back up to put the other two bolts back in.
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Great write up. I am a lot better at it the second time. I would not take off the sherwood water pump. Those 4 bolts are really tough to get on one handed. Probably worse than the impeller. A trick I was shown. Zip tie the impeller to a smaller diameter push on to align the shaft after using Dawn in the housing. Then snip the zip tie after it is in most of the way. I did bump the keyway to the very top so that I wouldn't drop it and did the other stuff you mentioned.
 
Hi, anyone with a Vetus bow thruster know if there is a breaker or switch anywhere? Where are all the fuses? I’m not getting power. Thanks,Greg
 
TotallyGross said:
Great write up. I am a lot better at it the second time. I would not take off the sherwood water pump. Those 4 bolts are really tough to get on one handed. Probably worse than the impeller. A trick I was shown. Zip tie the impeller to a smaller diameter push on to align the shaft after using Dawn in the housing. Then snip the zip tie after it is in most of the way. I did bump the keyway to the very top so that I wouldn't drop it and did the other stuff you mentioned.
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What a fiasco. It took 9 hours to get the port impeller changed. And this was with a knowledgeable mechanic. Ever have one of those projects where it should only take a couple hours, but you get setback after setback? That was today.

Started out trying to just take out the impeller, in place, from above. To get the hatch open enough for access we DID have to remove the entire sofa, including the metal frame. Not hard.

Then we started on the impeller. Taking out 2 of the three bolts, my impeller pump face plate would not swing entirely out of the way to allow the impeller to come straight out. Rotating one way it hit on the engine , the other way the lower hose. No biggie. Took all three bolts off.

Used an impeller puller but the impeller would not come out. The puller went in and actually threaded itself on top of the key. When we got the impeller puller to turn, we were turning the engine, not the tool. It was stuck hard. I do not recommend those screw on impeller puller tools. As I learned, they can thread down and trap the key in the threads, jamming up everything. Use one of those tools that you thread one part on and then thread a smaller bolt through the middle, so the smaller inner bolt screws down and pushes out the impeller. Or use needle nosed pliers. But only if you’ve greased the impeller shaft previously.

So we pulled off the pump. Only two bolts but not easy. And very heavy! Pulled off one of the elbow fittings to get access to the impeller inside of the pump body. We began prying out the impeller from the bottom. After a lot of effort, it came out. The shaft was bone dry. No silicone, nothing. Recommendation: put something in there! Non petroleum based grease/anti seize. But use something on the shaft!

Reattaching the pump wasn’t easy either. So far we had done everything from above. We could not get the pump back on from above. It was too heavy, and hard to align the gears and keep the gasket in place, from above. Off came the airsep assembly and the aftercooler. Lots better access for my 6’3” lean helper. Still not sure I could’ve gotten in there to install the pump. But I might be able to get in that way to pull and install an impeller. Maybe we will see in 2024…

Got the pump back on. The AC reinstalled and the airsep assembly put on. Opened the seacock and ran the engine. Good flow and no leaks! Success. But like I said, it took about 9 hours, all told.

Bonus: my port oil gauge had been bouncing around during use. While behind the engine my helper saw there was no but on the oil sender post. The terminals were just hanging there. We put a nut on and tightened and the helm gauge reads solid. Small victory but a victory.

So would I do this again? I honestly don’t know. I’m exhausted and frustrated with this project. I’m smarter, so next time I might just go in from the rear where I will have good visibility and direct access to the impeller. But I’m not convinced I could squeeze myself in that way. Fortunately, I don’t have to make this decision for 2 years.
 
You at least have the option of changing out to an SMX pump. With CATs one is stuck with Sherwood. The 400 saddle tanks make outside engine service extremely difficult. My young mechanically inclined nephew and I gave up after two hours of trying to insert the new impeller on the easy side. The pro took 45 minutes using wd40 to lube it. Another two hours on the hard side hanging upside down over the engine. The damn things have blind keys so with the key installed first there iis no way to twist the impeller in nor can the key be inserted afterwards.
I do not carry a spare now as there is no way I could ever replace one at anchor and will be writing checks next time untill someone designs a better pump.
 
Sounds like that was a pita Scoop, but also sounds about right, at least for most of us. For next time, just think about the time it took to do the aftercooler removal method and consider you won’t be exhausted when you start it. Have a moving blanket or some kind of soft pad to put over the top of the rear outside motor mount so when you lay on it you don’t get a self performed appendectomy, and a stud to thread into the top hole of the mount to slide the pump over to hold it while you install the bottom bolt will help a lot when you bolt in those new SMX pumps. Good job!
Oh, and some paint to take care of the rust starting to build back there, as long as your back there.
 
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