Micron Rating for Water Separator

[sailorbob]

The technical guy at my dealer recommends using a 30 micron Racor element, rather than the 10 micron element. He suggests that I change all three filters - Racor, Westerbeke and the inline filter by the lift pump - at the same time, so I get the bleeding process out of the way all at once. I was not aware of the inline filter, or I would have kept a spare aboard. I don't see one referenced in the Fuel System section of the Universal Operators Manual or in the Universal Parts List. Any idea where I can find the reference to this filter? I have a vague recollection there may be such a thing in the Universal Parts Kit A, but that's aboard the boat 75 miles away, which is also why I can't just look at the engine for this filter! I'd like to order a spare before the season gets underway.

Thanks!

Bob Fine
Second Wind #301

[wolfe10]

I get confused by the "primary/secondary" terminology - which filter is primary and which is secondary?

Bob

Fuel tank, primary filter/ water separator (Racor), electric lift pump, secondary filter (on engine), injection pump.

Brett

[sailorbob]

Thanks - I knew about the primary and secondary filters (Racor and Westerbeke threaded on) but I'm asking now about a third filter - apparently in line, by the lift pump.

Bob
Second Wind #301

[wolfe10]

I get confused by the "primary/secondary" terminology - which filter is primary and which is secondary?

Bob

Fuel tank, primary filter/water separator (Racor), electric lift pump, secondary filter (engine mounted), injector pump.

Brett

[R.B.]

Here is a picture someone else posted a number of years ago. I believe this is the filter you are referring to:


The parts manual does not show it but at the back of the manual they reference a filter that is not displayed:
P/N: 032974 I am not near the boat to confirm that this is the correct part number. Maybe a call to your local Universal dealer might confirm it.

As far as primary and secondary, yes it is confusing even the Universal technical manual on page 56 mentions that the on-engine universal fuel filter is the primary fuel filter, making the Racor the secondary. Also of note: the manual states on the same page that the fuel going into the lift pump should be filtered to 10 - 25 microns or smaller.

[wolfe10]

Unless someone is "reinventing the wheel", Primary if the first filter the fuel sees, Secondary the second. Same in on-road diesels.

Part of the confusion may be that the engine manual was written for a number of different application/installations. They don't necessarily all have to be like ours.

And a 10-30 micron Primary (before lift pump) makes complete sense, with the Secondary filter being the fine filter.

Brett

[wolfe10]

This article I wrote that will appear in the FMCA Magazine (Family Motor Coach Association)-- note the similarities between the fuel systems on large diesel motorhome and our Catalina 350:

Diesel Fuel Filters
By Brett Wolfe
The typical fuel system for a diesel coach is (in order): Fuel tank, primary fuel filter/water separator (course filter element-- 10 or 30 micron), lift pump, secondary fuel filter (2-5 micron filter element) engine. With the above system, you use either a 10 or 30 micron primary filter element and a 2-5 micron secondary filter element—final filter micron rating speced by your engine manufacturer. If only a single fuel filter, the filter element MUST BE THE MICRON RATING SPECED BY YOUR ENGINE MANUFACTURER (either 2 or 5 in most cases).
Here is the rub. Go into a dealer and ask the parts guy for a fuel filter element for a XYZ motorhome chassis or engine. If the last 4 filter elements that parts guy sold were for the two filter system, IT IS QUITE LIKELY THAT HE WILL JUST HAND YOU A 10 OR 30 MICRON ELEMENT-- it will fit. YOU WILL BE SPENDING BIG BUCKS TO GET THE "ROCKS" OUT OF THE INJECTORS-- ACTUALLY YOU WILL BE REPLACING THEM if you have a single fuel filter. By the same token, if you have the two filter system and the last 4 filter elements he sold were for the single filter system, it is quite likely that he will just hand you a 2 or 5 micron element-- almost as bad. You now have a two micron element followed by another 2 micron element. The first will clog up quickly and the second will get a "free ride".
Moral: Specify what micron rating filter element(s) you need for YOUR application. BETTER, know the part number(s) for the correct element(s) and ask them that part number(s). Consult your chassis or engine manufacturer for the correct part numbers.
Important—follow your engine/chassis manufacturer’s recommendation for proper filter replacement procedure. Some call for installing filters dry and using the manual primer pump to prime, some require pre-filling filters, some use an electric fuel pump to prime, etc. What works well on another engine or chassis may not be correct for yours.
If your system calls for pre-filling the filters with clean diesel before installing, be sure, particularly on the secondary fuel filter to fill ONLY the small outer holes (inlets), NOT the large center hole (outlet). Anything that goes into the center hole will go directly to the injectors with no filtration! Ya, it takes a lot longer to fill this way, but it is safer than "hoping" that you have no contaminants in the fuel (and you can not see a 5 micron particle with the naked eye). Unlike most maintenance items, there is NO AVERAGE LIFE for a fuel filter. If all it sees is clean fuel, it could go for years. One tank of contaminated fuel could clog several sets of filters. ALWAYS CARRY AT LEAST ONE EXTRA SET OF FUEL FILTERS (two sets is even better insurance). You can find someone to install them virtually anywhere in the world, but may not be able to get the proper filter elements in the boonies. Mark the date on the filters when you buy them so you use "oldest first" and buy a new replacement that goes into your parts bin on the coach.
If you have a filter with a clear bowl (my preference, as you can tell at a glance if there is contamination in the fuel) buy a spare plastic bowl. They can crack, and it is much easier to fit the bowl on the new filter before you even start changing filters. Then take the present plastic bowl and make it the spare for the next change.
Modern diesel engine’s fuel systems are "HIGH BYPASS". For every gallon of diesel pumped through the engine, only a few ounces are burned. The rest is used to cool and lubricate the head and then returns to the fuel tank. What this means in practical terms is that the next time you stop after refueling you should visually check the primarily filter (those with a clear bowl filter), as dirt and water will show up very quickly if present.
On any diesel engine, if you begin to lose power under heavy throttle conditions, the first thing to do is to replace the fuel filters. Why-- because it is easy, reasonably inexpensive and often the cause for the problem. Clogged filters start causing
performance issues under high throttle condition, since that is when maximum fuel flow is required. Sure, there can be other causes of loss of performance, but this almost always a reasonable starting point.

[KenKrawford]

Good information Brett. Thanks for posting this.

[saileagleswings]

Right or wrong, I have always used the 2 micron Racor filter. I personally think for me, changing the Racor filter is easier than changing the primary filter. Since I have an ample supply of both engine & Racor filters, I will stick with them until I run out. I have always replaced the Racor filter annually but not the engine filter.

Last spring, we went to the Exumas and back putting 200 hours on the engine. Had no engine issues at all. No filter changes in route.

Back home in Punta Gorda, I always buy fuel with Bioguard already added. I also try to keep the fuel tank level 3/4 - full. Also, I always check the Racor bowl with a flashlight before any cruise.

[sailorbob]

Racor has come out with a new device - a "T Handle Vacuum Indicator Kit" part RK 32348. It replaces the T handle on top of the Racor unit with a T handle topped off with a gauge. It seems like a perfect addition, giving an easy indication of the filter's status, but it adds 3.8" to the height of the entire assembly, and I don't think there's room in the engine compartment. Has anyone had any experience with this Racor product? I like the idea of taking the guess work out of when to replace the filter element.

Bob
Second Wind #301

[R.B.]

I have also had a vacuum filter ontop of my Racor for years and highly recommend it. The max stop needle is very beneficial for telling you the max vacuum throughout your engine use, not just the current vaccum.

I bought mine here (no affiliation):

http://www.sailorssolutions.com/index.a ... tem=VG01KT

[knitchie]

This thread goes back a while and ended with comments about installing the Racor vacuum gauge. For those who have installed the gauge, where did you find the headroom to install the Racor filter and gauge since the gauge adds almost 3” to the top of the filter housing?

In my boat, the Racor is installed behind the M35B in the starboard aft corner of the engine room wall under the horizontal access panel of the aft berth. If I move the mounting down far enough for the gauge to clear the cover, the bottom of the bowl is resting on the heat exchanger. Can’t imagine the engine vibration won’t destroy the filter in short order. I looked at moving the filter around the corner on the aft wall, but there is no better clearance to the heat exchanger.

My last resort might be to cut a notch out of the cover to give an extra 1/2” or so clearance between the filter bottom and heat exchanger.

Any other better ideas?

Thanks,
Ken - Reverie - Catalina 350 #447

[knitchie]

I stumbled upon a solution when looking at the possibility of using a short pigtail of compressor hose and found a rotating fitting. Installed, it only pushes the cover up a quarter of an inch.

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