Primary Diesel Filter/Water Separator Recommendation

[colemj]

Originally Posted by Guy

I would vote for the filter on the engine to be the primary filter. If this were in a taxi cab the filter on the engine would probably be the only filter, ie the primary.

This isn't a matter of a vote - the terminology is standardized in the industry, and has been that way for eons. You can call it whatever you want, but if you are describing a problem or ordering a part, you won't be understood unless you use the correct terms.

Mark

[skipmac]

Originally Posted by delmarrey

Why would you put a fine filter in front of a course filter. That's like putting a coffee filter in front of a spaghetti strainer.

If you look at boat/motor manuals the primary filter is the first from the tanks.

I just checked 8-10 different websites including those by filter manufacturers, engine manufacturers, maintenance and repair help sites and all of them agree.

Primary is the first filter IE just after the fuel tank, secondary is the second in line, after the fuel pump but before the injector pump and injectors.

[model 10]

Originally Posted by colemj

This isn't a matter of a vote - the terminology is standardized in the industry, and has been that way for eons. You can call it whatever you want, but if you are describing a problem or ordering a part, you won't be understood unless you use the correct terms.

Mark

You sound certain.

[delmarrey]

Originally Posted by Guy

You sound certain.

Certain that you'll get the wrong part if you don't get your terms right.

[colemj]

Originally Posted by Guy

You sound certain.

You sound confused!

Mark

[model 10]

Originally Posted by colemj

You sound confused!

Mark

Not any more. Thanks to a very complete fuel system primer from Catilpiller you are completly right..

[Badsanta]

Cool. But it is confusing. And so many get it wrong. It really makes it difficult when everyone is talking apples and oranges as the same. The motor comes with a filter, the primary. Anything added is secondary..Even if the second one is larger and the fuel goes through it first.
I was just bringing it up, because when you through out primary or secondary it is confusing. I can only say that when I get filters for my yanmar the primary is on the engine. I gess the others are differant..

[colemj]

I'm not trying to be pedantic or "sticking to my guns" or throwing out terms, I am just trying to talk apples to apples. It is those confusing primary with secondary that are putting oranges into the mix. Your motor comes with a secondary filter, and instructions to fit a primary filter when installing the engine. The secondary filter on Yanmar is on the engine. Other engines are the same.

Mark

[delmarrey]

Originally Posted by Badsanta

Cool. But it is confusing. And so many get it wrong. It really makes it difficult when everyone is talking apples and oranges as the same. The motor comes with a filter, the primary. Anything added is secondary..Even if the second one is larger and the fuel goes through it first.
I was just bringing it up, because when you through out primary or secondary it is confusing. I can only say that when I get filters for my yanmar the primary is on the engine. I gess the others are differant..

Hum! My Yanmar manual doesn't say either way.

[model 10]

Originally Posted by delmarrey

Hum! My Yanmar manual doesn't say either way.

I thought you guy's were certain?

[colemj]

Originally Posted by delmarrey

Hum! My Yanmar manual doesn't say either way.

Your schematic confuses me. It looks like you have a water separator and a primary fuel filter before the lift pump, but no secondary filter after the lift pump. It also labels a fuel line as the injection pump. Then there is a big blank space where something magical occurs...

Mark

[model 10]

Originally Posted by colemj

Your schematic confuses me. It looks like you have a water separator and a primary fuel filter before the lift pump, but no secondary filter after the lift pump. It also labels a fuel line as the injection pump. Then there is a big blank space where something magical occurs...

Mark

That is not the lift pump it's the high pressure pump. There is no lift pump in the diagram

[delmarrey]

Originally Posted by colemj

Your schematic confuses me. It looks like you have a water separator and a primary fuel filter before the lift pump, but no secondary filter after the lift pump. It also labels a fuel line as the injection pump. Then there is a big blank space where something magical occurs...

Mark

That was a 4JH system. They have internal elect'l lift pumps
Here's a 3JH maybe it makes more sense.

.

[skipmac]

Originally Posted by Guy

I thought you guy's were certain?

Well after a bit of research, I'm certain. Lets start with a quote from the report of the 7th International Filtration Conference.

A typical diesel fuel filter system uses a primary filter on the suction side of the fuel pump and a secondary filter on the pressure side.

http://www.lydallfiltration.com/tech...uelFilters.pdf


And for additional confirmation.

Most diesels have two fuel filters: a “primary” filter located between the fuel tank and the engine, which cleans the fuel before it gets to the fuel transfer pump; and a “secondary” filter up near the engine, which gives the fuel a final cleaning before it gets to the fuel injectors.

Tips for Changing a Diesel Engine's Air and Fuel Filters - For Dummies



The primary fuel filter must offer low restriction because it is mounted on the suction side of the fuel pump where normally a suction pressure of only 5-6 pounds per square inch is available. This filter has the job of protecting the transfer pump and lightening the load of the secondary fuel filter (if installed). Primary fuel filters typically have a nominal rating of 10 - 30 microns.

Heavy Duty Diesel Fuel Filter FAQs



Fuel filter performance and technology have also been challenged by these rapid advancements. Today it is common to demand secondary filtration of 3-5 µm absolute efficiency, while matching with an upstream primary filter of 7-25 µm. These changes come with the expectation that water separation, filtration life, and packaging space remain constant or are improved upon. Donaldson engineers have proven to be up to this challenge through the advancement of media technologies.

http://www.donaldson.com/en/engine/s...ary/070616.pdf

If you want to google the question you can find many more that all say the same. So, seems like people in the industry pretty much agree on which is which.

[sy_gilana]

I would look at the Davco unit. Nice that you can change the filter element while the engine is running. Also nice to see the state of the filter at any time. Bleeding is no problem. No need for a duplex, if it clogs just change it. Also it can accept a number of filter elements, Racors, CAV,'s Wix, Purolator, Fram, Napa, Yong Ching...any filter that is x by y dimensions...
DAVCO Technology, LLC