Cat 3126 raw water pump

[carterchapman]

Mine gets done every other year. I used the zip ties when I did them the first time two years ago.
The pump on the port motor was no problem because I had plenty of room to work comfortably.
But the starboard side on my 410 is a whole lot harder to deal with. Even with the exhaust removed I was in an awkward physical position wedged between the motor and the generator while working the impeller in to the pump.
Between wrestling with the starboard exhaust hoses and then the impeller I’m deciding between either having the boatyard do it or springing for the impellertool.
I’m leaning towards paying the boatyard to do the job. The only thing holding me back is that if I do it myself I can do some cleaning and touch up over the course of several sessions on the outboard side of the starboard motor while I have the exhaust hose off.

JVM - I found servicing the genny was easiest with the main hatch closed and the genny hatch removed. I laid on my stomach and just reached down - fuel filter, oil filter and impeller....

 

[JVM225]

JVM - I found servicing the genny was easiest with the main hatch closed and the genny hatch removed. I laid on my stomach and just reached down - fuel filter, oil filter and impeller....

That’s the way I do the oil filter and zinc.
I’ve only done the impeller once, but I did it while I had the starboard exhaust apart to change the impeller on that motor.

 

[JVM225]

It is worth removing the starboard exhaust as well as the aluminum hatch channel. Once those are removed it makes it way easier although it helps if you can work well with just your left hand! Also pick up a cheap chase lounge pad to throw over the top of the engine to keep from bruising your chest.

I remove that channel too. It really does make a lot of things easier to do.

 

[mrsrobinson]

Regarding removing the channel, I saw the 2 screws at each end, is that it? I thought I saw some caulk/silicone on the ends too.

 

[Strecker25]

Regarding removing the channel, I saw the 2 screws at each end, is that it? I thought I saw some caulk/silicone on the ends too.

Ours is bed in silicone to stop cockpit water from dripping down. Not so important if it’s always dry but I hose our seadek down after the weekend so mine needs to be sealed

 

[dtfeld]

Anybody ever try the spline shaft pump? The OP was correct that the key is the tricky part of reinstalling the impeller.

 

[mrsrobinson]

For those following along at home and want to better understand the service, my girlfriend's brother-in-law stated he could tell the injectors had never been adjusted before. There's a wire of some kind installed at the factory at cylinder number one. I forget what he called it, he explained it to me. There's also a small piece of yellow at cylinder number one. Based on this and some other things he saw at cylinder number one he knew they had never been adjusted.

He also said he could tell the water pump belt had never been replaced because it still had factory white paint on it. He can't say the same about the alternator since the alternator is installed after the engine leaves the factory and is not painted. His assumption is, like mine, it's never been replaced. He also said he tightens them as best he can when they're new because he knows for a fact they will loosen/stretch, and will need to be checked again shortly.

He went through the boat and did a lot of clean up, like straightening out wires, putting new zip ties in and such. He noticed a crimp in the antifreeze line running from the engine mounted tank to the expansion tank. Looks like it was putting back pressure on the engine so we replaced it with a new line and new clamps. Even though the engine tank cap looks good to my eye, he can tell it needs to be replaced so I'll be replacing that.

He's done everything to these motors when he was a mechanic, including full rebuilds. He was impressed with the motors, said they run strong and said they have always been his favorite engine to work on, that they're pretty much indestructible if you take care of them. I asked him what the difference was between working on them and working on motors at the shop and in the field. He said it was a challenge but better than he expected. He said the worst application is RVs and buses based on how the engines are installed.

I wish I had turned a recorder on because I couldn't keep track of all the tips and things he was sharing with me, but I remembered a few.

 

[fwebster]

Somewhere in the shuffle of surveys, closing, relocating the boat ,etc. you apparently lost the email I sent explain the importance of resetting the engine overheads at the factory recommended interval. That service covers resetting the intake and exhaust valves and resetting the injector timing and it is important because if neglected, the valves can open too far and impact piston crowns WHICH IS ALMOST ALWAYS A TERMINAL EVENT FOR 3116 AND 3126 Caterpillars. A 6 hour service call by your brother-in-law if he has the tools and gauge blocks necessary will be a lot cheaper than a $40,000 engine. Don't wait…..do the overhead service Now!


The overhead service usually gets you a quieter, smoother idle, less soot and a bit more efficient fuel economy.

 

[fwebster]

Anybody ever try the spline shaft pump? The OP was correct that the key is the tricky part of reinstalling the impeller.

Never……….! The method of getting the old impeller out of the pump housing on the Cat/Sherwood pump with a bolt is supremely easy and gets vastly more complicated if you get a seawater leak in the pump with a splined shaft. Corrosion kinda welds the splines on the shaft to the impeller hub.

The trick to the key and key way on the Sherwood pump is to take about 400 grit enery cloth or sand paper and polish the edges on the new keys before trying to install them…..polish the edges and the ends to just knock off the sharp crown; do not try to sand the flat side of the key.

 

[Strecker25]

Somewhere in the shuffle of surveys, closing, relocating the boat ,etc. you apparently lost the email I sent explain the importance of resetting the engine overheads at the factory recommended interval. That service covers resetting the intake and exhaust valves and resetting the injector timing and it is important because if neglected, the valves can open too far and impact piston crowns WHICH IS ALMOST ALWAYS A TERMINAL EVENT FOR 3116 AND 3126 Caterpillars. A 6 hour service call by your brother-in-law if he has the tools and gauge blocks necessary will be a lot cheaper than a $40,000 engine. Don't wait…..do the overhead service Now!


The overhead service usually gets you a quieter, smoother idle, less soot and a bit more efficient fuel economy.

not to take this thread on a detour but I’ve never asked Milton (who did this service) whether this job was considered the full 250hr overhead and injector service. These are the notes from when it was done - I’ve always believed it covered Everything needed and we are good until 2000hrs. Would you a agree @fwebster?


Customer complaint: Inspect engine for rough running
Resultant damage: Combustion gas in fuel system-engine rough running
Cause of failure: Injector seats leaking combustion gas
Repair process comments: 4/14/20: Inspected engine for rough running. Customer had new fuel filters, changed fuel filters on both engines. The Starboard engine still sounded like it was running rough/stumbles on acceleration. Installed clear fuel lines and ran the engine, found return fuel to have signs of combustion air in it-supply fuel to the cylinder head was clear with no air. Turned fuel off then disassembled top end and removed all six injectors-cylinders 3,5& 6 showed combustion gas leaking by at the injector seat. Cut all six injector cups then resealed and reseated all six injectors using tooling.
4/15/20: Performed injector synchronization. Reinstalled and torqued rocker assemblies. Adjusted valve lash and injector timing dimension. Installed valve cover and primed fuel system. Reinstalled clear fuel line on the return, started engine and return fuel was clear with no signs of air. Shut engine off and removed clear lines then restarted engine and allowed the engine to reach normal operating temperature-the engine sounded good with no stumble on acceleration. The engine is running properly at this time.
Talked with customer about checking the other engine for air in the return fuel & performing a top end adjustment-The customer agreed to have this
performed. Installed clear line in the fuel return, it checked good no signs of air in the return fuel. Removed valve cover & visually looked good. Adjusted valves & injector timing dimension. Reassembled ran & rechecked for leaks, all checked ok at this time. Port Engine Hours: 797
Starboard Engine Hours: 811

 

[Maybe A Dancer]

Somewhere in the shuffle of surveys, closing, relocating the boat ,etc. you apparently lost the email I sent explain the importance of resetting the engine overheads at the factory recommended interval. That service covers resetting the intake and exhaust valves and resetting the injector timing and it is important because if neglected, the valves can open too far and impact piston crowns WHICH IS ALMOST ALWAYS A TERMINAL EVENT FOR 3116 AND 3126 Caterpillars. A 6 hour service call by your brother-in-law if he has the tools and gauge blocks necessary will be a lot cheaper than a $40,000 engine. Don't wait…..do the overhead service Now!


The overhead service usually gets you a quieter, smoother idle, less soot and a bit more efficient fuel economy.

>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>

In the 3116/3126 thread I recently posted the results of my own 250hour service, performed by Miley CAT in Ft. Myers

engines are definitely smoother and quieter and I picked up some WOT RPM as well.

less "diesel clatter" at idle and smoother /quieter at cruise.

Expensive, yes, but if you spread that cost over the next 1,750 hours its really not significant.

BEST !

RWS
Suggest you heed the sage advice of Dr. Webster

 

[fwebster]

not to take this thread on a detour but I’ve never asked Milton (who did this service) whether this job was considered the full 250hr overhead and injector service. These are the notes from when it was done - I’ve always believed it covered Everything needed and we are good until 2000hrs. Would you a agree @fwebster?


Customer complaint: Inspect engine for rough running
Resultant damage: Combustion gas in fuel system-engine rough running
Cause of failure: Injector seats leaking combustion gas
Repair process comments: 4/14/20: Inspected engine for rough running. Customer had new fuel filters, changed fuel filters on both engines. The Starboard engine still sounded like it was running rough/stumbles on acceleration. Installed clear fuel lines and ran the engine, found return fuel to have signs of combustion air in it-supply fuel to the cylinder head was clear with no air. Turned fuel off then disassembled top end and removed all six injectors-cylinders 3,5& 6 showed combustion gas leaking by at the injector seat. Cut all six injector cups then resealed and reseated all six injectors using tooling.
4/15/20: Performed injector synchronization. Reinstalled and torqued rocker assemblies. Adjusted valve lash and injector timing dimension. Installed valve cover and primed fuel system. Reinstalled clear fuel line on the return, started engine and return fuel was clear with no signs of air. Shut engine off and removed clear lines then restarted engine and allowed the engine to reach normal operating temperature-the engine sounded good with no stumble on acceleration. The engine is running properly at this time.
Talked with customer about checking the other engine for air in the return fuel & performing a top end adju stment-The customer agreed to have this
performed. Installed clear line in the fuel return, it checked good no signs of air in the return fuel. Removed valve cover & visually looked good. Adjusted valves & injector timing dimension. Reassembled ran & rechecked for leaks, all checked ok at this time. Port Engine Hours: 797
Starboard Engine Hours: 811

This statement indicates that the engine overheads were reset: "Adjusted valves & injector timing dimension." As far as good to 2000 hours…….probably but any time you change a valve lash or an injector setting, you will need to reset the valves or injector timing. You had leaking injector cups on 3 cylinders and the mechanic reamed those three and the other 3 on the same engine so that engine should be good for the 2000 hours. However, the mechanic just checked the return fuel on the other engine and found them not leakingany combustion gasses when he checked them. That means that any of those 6 injectors could begin tomorrow, next wee or 3 years from now and then you will need to ream those injector cups and reset the injector timing on that engine which could be at anytime before you get to 2000 hours.

Frank

 

[mrsrobinson]

I thought I did heed his advice, and I did notice the engines were a little quieter at idle after the valve lash adjustment. The only thing we did not do were the injectors, he didn't have the tool to do so. He showed me and explained how it all works though.

He's not a marine caterpillar mechanic. He did say he's never seen an issue with a truck, rv, heavy equipment engine because the valves or the injectors we're not serviced on time, that it's something good to do anyway at the recommended intervals. When I asked him in priority what should we do first his biggest concern was the belts.

I had a mechanic scheduled to do all of this work (the work we did yesterday) the week after July 4th, including the valve lash and injectors. My brother-in-law had availability yesterday so I took him up on it, plus I wanted to learn.

When everything but the aftercoolers, raw water impellers and valves/injectors, which were not on our list to do, were done he said he had some more time, he could do the valve lash while he's there. I thought this was a time consuming job. He said no, pull the valve covers, then top dead center on the flywheel for cylinders 1 and 6 (2 times), do the adjustments, reinstall valve covers. I asked if it was ok to do this and not the the injectors at the same time, he said yes. So my thought was at a minimum I would learn and save some $$$ if the other mechanic only had to do the injectors. Or, I purchase the tool and we do the injectors together soon. Once the covers were off he noticed what I mentioned about them still being "factory".


The mechanic I had scheduled to do all of this work the week after July 4th, thinks he can move some things around and come down this week and do the injectors, the raw water impellers and the after coolers. If he can, yay, we can go on our our July 4th weekend boat trip. If he can't then I will do as much as I can on my own next weekend.

 

[Strecker25]

This statement indicates that the engine overheads were reset: "Adjusted valves & injector timing dimension." As far as good to 2000 hours…….probably but any time you change a valve lash or an injector setting, you will need to reset the valves or injector timing. You had leaking injector cups on 3 cylinders and the mechanic reamed those three and the other 3 on the same engine so that engine should be good for the 2000 hours. However, the mechanic just checked the return fuel on the other engine and found them not leakingany combustion gasses when he checked them. That means that any of those 6 injectors could begin tomorrow, next wee or 3 years from now and then you will need to ream those injector cups and reset the injector timing on that engine which could be at anytime before you get to 2000 hours.

Frank

roger that. I’m always keeping an ear on the noises and how that port engine is running for signs of leaking cups on that side. From talking to the caterpillar dealer it sounds like there’s really no set reason they might begin to leak but rough starting and rough idle is a good indicator