Universal Diesel Fuel Pump Question

Nov 28, 2021
4
Jensen Marine CAL39 Boston
I have a CAL 39 with a Universal 5444 (M50) diesel. I recently purchased this boat and am going through the engine. I noticed that I only have an electric fuel pump between my tanks and the engine. I also have a pdf Parts List from Westerbeke for this engine. The schematic in the pdf shows a mechanical lift pump (P/N 299425) which mounts on the side just below the injection pump. My engine does not have this mechanical pump. Instead it has a blank cover where the pump should be. Does anyone know or have an opinion as to why this might be and should I purchase and install one? I would appreciate also any other Universal diesel owners letting me know if their engine has one or not. The year of my boat is 1982. Many thanks in advance.
 
Nov 22, 2011
984
Ericson 26-2 San Pedro, CA
It appears that previous owner swapped out the mechanical lift pump with an electric one and covered over the location where the lift pump originally was. This is not a bad thing. I, too, replaced the mechanical lift pump on my Yanmar 1GM with an electric pump.

There are a few good reasons for doing this. First, the mechanical lift pump has a diaphragm. Should the diaphragm become breached, it can allow fuel into the oil. The electric pump eliminates this as a possibility. Second, depending on how you have your system plumbed, the electric pump makes it trivial to prime your dry filters during a filter change and also to bleed your fuel system.
(While the mechanical pump designed for your engine likely has a priming lever for this purpose, it also may not work very effectively. The one on my Yanmar certainly didn't.)

I'd say that if your current fuel pump is working fine, leave it alone.
 
Oct 22, 2014
16,409
CAL 35 Cruiser moored EVERETT WA
You need a pump to move fuel from a tank placed below the engine to the high pressure pump that boosts the diesel fuel pressure to properly inject the fuel into the air mixture in your cylinders.

The original design had a mechanical pump that provided this service. It sounds like your previous owner modified the system by installation of an electric pump. There are advantages and disadvantages. Either way you need to draw the fuel into the engine.

With the electric pump functioning, be sure that it is maintained and all will be fine.

There are location considerations with an electric fuel pump. Many say that the pump needs to be between the engine and a primary filter. This way the pump will not get clogged, as the filter will mitigate any contaminates that occur in your fuel tank.

It appears in your message that the pump is before the filter. If so, you may want to check if the pump has a screen or filter. This would be to protect the pump. Should your fuel become contaminated, this screen/filter may clog, stopping the flow of fuel. This would be an important maintenance item for your boat.
 
Nov 28, 2021
4
Jensen Marine CAL39 Boston
So the choice Is between an electric pump that may fail and a mechanical one that may leak. Seems like there are many more stories of electric pump failures on the forums. Perhaps a combination that uses the mechanical one as primary to draw through the electric and using the electric for a backup and for system purging when changing the filters.
 
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Nov 22, 2011
984
Ericson 26-2 San Pedro, CA
So the choice Is between an electric pump that may fail and a mechanical one that may leak. Seems like there are many more stories of electric pump failures on the forums. Perhaps a combination that uses the mechanical one as primary to draw through the electric and using the electric for a backup and for system purging when changing the filters.
Electric pumps are highly reliable--or at least the highly reliable ones are! For example, the Facet Gold Flo are quite good. Plus, I don't think electric fuel pump failures are all that common as a rule, and I read a few different sailing fora daily. Sure, it happens, but not that often.

Also, the form of your statement suggests that mechanical ones don't fail but merely leak. They do indeed fail as well as leak. And one needs to consider also one of the failure modes when they do go. If the electric pump craps out, your engine will die. If the mechanical one has the diaphragm leak, it dumps diesel fuel into your oil pan. I'd surely choose the former over the latter any day.

Consider also that if one is overly worried about the very unlikely event that a decent electric pump would fail, one could always carry a spare that could be easily swapped in. Set it up with quick disconnect connectors both for the hoses and for the wiring and you could switch it out in a few minutes. Swapping out a mechanical pump would almost certainly be a bigger job.

In any event, many (most?) diesel engines only have electric pumps, including the larger Universal models, and they all seem to do just fine. (My previous boat had an M25XP, with an electric fuel pump that was still going strong when I sold the boat.)

As for going with a combination: This may be a bad idea. Depending on the pump pressure, it *might* actually effect damage to the mechanical pump's diaphragm. In any case, there's no reason to do it because an electric pump is just fine, and if one really wants redundancy, carrying a spare electric pump will do the trick.
 
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Dan33

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Nov 25, 2019
3
Oday 39 Charlotte Harbor
I owned a 1982 O'day 39 with Universal 5444 engine and it came from the builder with electric fuel pump.I had this boat for 18 years,lived aboard for 11 years and cruised the Caribbean for 5 years,all with the original pump.When it comes to bleeding the fuel system you will be glad you have an electric pump.
 
Nov 28, 2021
4
Jensen Marine CAL39 Boston
I owned a 1982 O'day 39 with Universal 5444 engine and it came from the builder with electric fuel pump.I had this boat for 18 years,lived aboard for 11 years and cruised the Caribbean for 5 years,all with the original pump.When it comes to bleeding the fuel system you will be glad you have an electric pump.
That’s very interesting. I posted my question because Universal included a mechanical pump in their own schematics with a part number. Now I’m wondering if they might have made a change during production and just switched over to an electric pump. I appreciate all the responses.
 
Nov 28, 2021
4
Jensen Marine CAL39 Boston
Electric pumps are highly reliable--or at least the highly reliable ones are! For example, the Facet Gold Flo are quite good. Plus, I don't think electric fuel pump failures are all that common as a rule, and I read a few different sailing fora daily. Sure, it happens, but not that often.
Alan, thanks for your input. I guess I would never have thought that this was true.
 
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