Perkins 4-108 water pump

[Xanthe]

My newly rebuilt 4-108 suddenly sounded loud and was shutdown once I realized there was no water coming out of the exhaust pipe.
Quickly determined that after removing the waterpump impellor, the shaft could be turned by hand. Removed the pump and found the shaft drive coupling had failed.
Question is; where are the broken bits. Are they at the bottom of the oil sump or rattling around ready to do damage when the engine is next running.

[model 10]

Oh man. They didn't align the water pump mount. There is a tool but you can do it without, but it is a little tricky.
I don't think the 2 ears can make the oil sump. They are probably down in the bottom of the timing cover.

[Xanthe]

Originally Posted by Ecos

Oh man. They didn't align the water pump mount. There is a tool but you can do it without, but it's a little tricky.
I don't think the 2 ears can make the oil sump. They are probably down in the bottom of the timing cover.

There is this alignment tool here, https://www.parts4engines.com/perkin...lignment-tool/
Not the same as the drawing in the workshop manual (attached). Looks like it is used with the water pump fully assembled. Does anyone have experience using this tool.
Looking at the photo K1 in the manual, gives me hope the bits are at the bottom of the timing cover. They'll have to come out. Hate to ruin the newly painted look.

[Lepke]

If the ears are in the sump they're no problem, but agree they're in the timing cover and could get involved with the oil flow around the crank gear at higher rpm. I think the timing cover will have to be removed. You probably can't get them with an extended magnet and in any case don't want to risk magnetizing the gear.

[model 10]

The 4 water pump mounting studs are welded to a ring that needs to be centered over the fuel pump drive gear and the opening in the timing cover for the water pump. There is a lot of movement possible so you can't just guess when you are putting the engine back together.

[Xanthe]

Originally Posted by Ecos

The 4 water pump mounting studs are welded to a ring that needs to be centered over the fuel pump drive gear and the opening in the timing cover for the water pump. There is a lot of movement possible so you can't just guess when you are putting the engine back together.

Thank you Ecos. There is this https://www.parts4engines.com/perkin...lignment-tool/ but its not the same as the drawing in the workshop manual(pic). Looks like it can be used on a fully assembled pump. Has anyone used this tool and commented on its accuracy.

[Xanthe]

Originally Posted by Lepke

If the ears are in the sump they're no problem, but agree they're in the timing cover and could get involved with the oil flow around the crank gear at higher rpm. I think the timing cover will have to be removed. You probably can't get them with an extended magnet and in any case don't want to risk magnetizing the gear.

Very sensible advice. Might be OK for calm weather, but there's no knowing for when it gets rough and you really need the engine.

[stormalong]

Go back to whoever rebuilt it and make them fix it. The timing cover must be removed and the timing gears must be inspected for damage.

[Xanthe]

Originally Posted by stormalong

Go back to whoever rebuilt it and make them fix it. The timing cover must be removed and the timing gears must be inspected for damage.

Yes of course, but difficult in this case. There is an international border and some distance in the way. You can be sure some compensation will be sought.

[jimbunyard]

Any damage the broken pieces may have done is all that they're likely to do.

There is quite a bit of room between the crank gear and the bottom of the timing cover; it is unlikely in the extreme that any amount of 'rough weather' short of capsizing will get those pieces back in contact with a turning gear, in which case they'd likely be flung aside with no ill effect.

Of course, some just are uncomfortable with whatever level of uncertainty there might be, and there's a bit more possibility that the pieces might have caused damage that could eventually escalate into something worse, though this too is unlikely.



Since you have the pump off, can you tell if the coupling is iron (that's what it looks like in the picture) or aluminum? If aluminum, then you have no worries.

As for centralizing the drive, in section 'M' of this manual

http://www.atlanticmobilemarine.com/...p%20Manual.pdf

it describes a method of accomplishing this without the tool, essentially by loosening the bolts holding the drive plate so they will allow the plate to move but will hold it in position, installing the pump, turning the engine over several times and then carefully removing the pump and securely tightening the drive plate retaining screws.

I certainly don't expect you to take my word for this, but if the rebuilders are amenable to making good on their rebuild, perhaps you can take it back to them using the engine sparingly en route.

Me? If it ran and sounded OK after replacing the coupling (14.00 US from Parts 4 Engines) and aligning the drive, I'd run it as is...

[Xanthe]

Originally Posted by jimbunyard

Any damage the broken pieces may have done is all that they're likely to do.

There is quite a bit of room between the crank gear and the bottom of the timing cover; it is unlikely in the extreme that any amount of 'rough weather' short of capsizing will get those pieces back in contact with a turning gear, in which case they'd likely be flung aside with no ill effect.

Of course, some just are uncomfortable with whatever level of uncertainty there might be, and there's a bit more possibility that the pieces might have caused damage that could eventually escalate into something worse, though this too is unlikely.



Since you have the pump off, can you tell if the coupling is iron (that's what it looks like in the picture) or aluminum? If aluminum, then you have no worries.

As for centralizing the drive, in section 'M' of this manual

http://www.atlanticmobilemarine.com/...p%20Manual.pdf

it describes a method of accomplishing this without the tool, essentially by loosening the bolts holding the drive plate so they will allow the plate to move but will hold it in position, installing the pump, turning the engine over several times and then carefully removing the pump and securely tightening the drive plate retaining screws.

I certainly don't expect you to take my word for this, but if the rebuilders are amenable to making good on their rebuild, perhaps you can take it back to them using the engine sparingly en route.

Me? If it ran and sounded OK after replacing the coupling (14.00 US from Parts 4 Engines) and aligning the drive, I'd run it as is...

The drive coupling is definitely cast iron.
Thanks for the additional information.

[Xanthe]

Originally Posted by jimbunyard

Any damage the broken pieces may have done is all that they're likely to do.

There is quite a bit of room between the crank gear and the bottom of the timing cover; it is unlikely in the extreme that any amount of 'rough weather' short of capsizing will get those pieces back in contact with a turning gear, in which case they'd likely be flung aside with no ill effect.

Of course, some just are uncomfortable with whatever level of uncertainty there might be, and there's a bit more possibility that the pieces might have caused damage that could eventually escalate into something worse, though this too is unlikely.



Since you have the pump off, can you tell if the coupling is iron (that's what it looks like in the picture) or aluminum? If aluminum, then you have no worries.

As for centralizing the drive, in section 'M' of this manual

http://www.atlanticmobilemarine.com/...p%20Manual.pdf

it describes a method of accomplishing this without the tool, essentially by loosening the bolts holding the drive plate so they will allow the plate to move but will hold it in position, installing the pump, turning the engine over several times and then carefully removing the pump and securely tightening the drive plate retaining screws.

I certainly don't expect you to take my word for this, but if the rebuilders are amenable to making good on their rebuild, perhaps you can take it back to them using the engine sparingly en route.

Me? If it ran and sounded OK after replacing the coupling (14.00 US from Parts 4 Engines) and aligning the drive, I'd run it as is...

The broken drive coupling is definitely cast iron. Thanks for the additional information.