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Cummins 504M

liam

New member
Hi Chaps
I Have a 1971Van Lent with two Cummins 504m Diesels
one has a leak In the exhaust manifold
Has anyone got any info or diagrams on the exhaust system ,ie is it wet or dry ,ect
Thanks
Liam
 
Thank you so much Nikola, sorry for delay but could not remember my details

Dont suppose you know the position of the inline diesel filter

Regards

Liam
 
Hi Liam,

These fuel filters are most often specific for each boat, not for engine, depending where the manufacturer has decided to put them and which one. I have one V-504-M, but in a different boat, so not of much help to you. Since I have installed it myself, I do not have inline filter. I am not sure that would even be good idea due to very high fuel flow on that engine (at least I have never seen inline filters for such applications). Maybe you do think of that metal mesh inside the fuel pump, but that would be wiser for you to ask one of elderly Cummins engineers, since it is a part of fuel pump assembly.

What you can check, if you already haven't, if the fuel is reaching the fuel pump at all. At the inlet pipe of fuel pump (on the top of engine), there is a bolt. Put some towel below that (it is a bit tight) and unscrew the bolt, if the fuel is present it will flow out. If not, then your line or filters are clogged (or there is some valve somewhere). Of course, even if there is fuel, it does not mean that your filters are clean, but at least, you will know if the fuel is present at fuel pump. And I would do this anyway if it has not been started for a long time, or your filters have been changed, to purge the air from the system. After that, a bit longer cranking is needed, until the pump fill the whole fuel system. (Do this partialy, 30 seconds cranking, 2-5 minutes pause, for the sake of the battery, but if not making it after 10 attempts maximum, than you still have a problem with something). Hope this helps a bit, but I presume that you have already tried this.

Regards,
Nikola
 
Oh, one more easy check to do if the fuel is reaching the fuel pump. On the fuel pump is an electric valve that opens/closes the fuel to the engine. You can use voltmeter to check if there is a voltage present when you turn the key to RUN position (just contact position, not cranking position), but do not keep in that position for long period of time if not cranking or running, since there is the warning in the engine manual that it would lead to letting too much fuel in cylinders which could cause a hydraulic lock. If there is voltage present, this means that your wiring is OK, but it does not guarantee that your electric valve is OK (but it is very simple device). On the pump, near that valve, there is one bolt that can be turned with hand (not sure now for exact position), which you can use to mechanically open/close that valve in case electric one is malfunctioning (but it can be used even when valve is working OK). Turning it fully counterclockwise, valve is controlled only electrically, but turning it fully clockwise, you are opening that valve by hand permanently, independent of electric valve (same warning as before, do not open it for long time if not cranking or running the engine). You could turn that bolt by hand from end position to end position, if the valve is sticking inside (if engine has not been working for a long period of time, although, fuel is inside, which is a good lubricant). You probably know this, but maybe it helps a bit to resolve the issue.

Regards,
Nikola
 
Thanks Nikola and hi all
i decided to change the impeller in my Jabsco pump on the Cummins 504 however as there is very little clearance it appears it may have to be taken off first.
Has anyone else tried this ?
Regards
Liam
 
Depending of the boat, it can be hardly reachable, otherwise I don't see why not. However, I am using neither impeller either Jabsco pump so you should see the engine user/service manual or parts catalog. Or try to ask on Trawler forum guy called Clectric about it since he is using Jabsco impeller pump on V-555, very similar engine, maybe he can help you. While I was reading the forums about V-504s to inform myself about their reliability and problems, most problems were reaching equipment on the sides of engines in boats with twins.
Regards,
Nikola
 
as a rule, you are better off removing the pump and give it a thorough inspection....rather than just swapping the rubber impeller....on any engine...
 
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