Primary Fuel Filter Maintenance

[Mike Vaccaro]

In 2005, we installed a Racor 500-series turbine filter in our 1988 C34, Hull 563 equipped with a Universal M-25XPA engine.  There is a post on the projects page detailing the installation and the rationale for replacing the spin on filter with this more expensive filter.  The primary reason for swapping filter types was ease of maintenance.

This type of filter is remarkably easy to monitor and maintain.  On a daily basis, all that is required is to visually check the bowl for sediment or water before start and the vacuum gauge (when the engine is running) to determine the status of the filter.  No tools are required for basic maintenance of this filter.     

After two years we recently changed the 2 micron filter for the first time since the original installation.  Not because it was clogged (that would be evidenced by the vacuum gauge), but due to water and sediment in the fuel tank churned up during a recent refueling.  After refueling, we went for a sail to ensure that the tank was agitated and then tied up at the dock to drain the system of contaminants. 

As has been discussed in numerous threads on this board, the fuel tank should be cleaned at five-year intervals unless you are burning a bio-diesel mix (which keeps the system clean).  Regardless of fuel type, the tank should be inspected at five year intervals for signs of corrosion.

The inspection bowl is equipped with a quick-drain spigot that can be opened by hand.  It's simply a matter of opening the drain and draining the contaminated fuel into a bucket.  After removing the old filter, a wipe down will clean the assembly.  After replacing the filter, we primed the filter a total of five times (by simply turning on the electric fuel pump) and filling the filter assembly to drain all of the contaminants from the tank.  It's easy to see the water and crud being pumped from the tank by observing the bowl.  On the sixth "prime," the fuel ran clear and all sediment and water was drained.  This technique wasted about 3/4 of a gallon of fuel to produce just over a quart of water and sediment.  We treat our fuel with bio-bor to prevent algae growth and minimize sediment.   

After the fuel ran clear, we waited until the pump ticking slowed to indicate that the fuel had been pumped to the engine, opened the bleed thumb screw and started the engine.  As Stu pointed out in the "hard starting/glow plug" thread, there is no need to crack an injector on Universal engines equipped with a bleed screw.  After running the engine in gear at speed for 10-20 minutes, it's simply a matter of closing the screw.  As Ron Hill pointed out, it's permissable to leave this screw open slightly all of the time, making your system self-priming.       

This filter is also designed to allow this type of maintenance to be performed in a seaway, which could be critical if a large amount of contaminants are stirred up by the boat's motion, possibly to the point of clogging the filter. 

With tools (just a small socket wrench), this filter can be completely disassembled for a thorough cleaning.  If it's time to replace your spin-on filter or clean your fuel tank, you should consider installing this type of filter to simplify future maintenance. 

Cheers,

Mike 
   

[Jeff_McKinney]

Mike,

Thanks for sharing this clear and concise description of the process you followed.

One bit of caution (previously mentioned in other posts): If you switch to bio-diesel be prepared to have a lot of crud get into the filter as it comes off the tank walls. ALWAYS have spare filters handy. 

Fair winds.

[Stu Jackson]

Jeff's right.  An additional thought from a recent Cruising World magazine article:  in addition to the crud coming off the tank walls, don't forget to remember the HOSES.  They have buildup in them too.  Might be a good time to replace your fuel hoses when (if) you start using bio-diesel.

[Mike and Joanne Stimmler]

I use the Racor 45 S filter and I replace it on a regular basis but have never had to replace it away from the dock because of a clog. Also I have never seen any water in the bowl. I was wondering if anyone has tried to open up the old filter after replacing it to see how much crud it has filtered? Or is there a way to tell how much the filter has collected.

Also would it be possible or even feasable to re-route the fuel line so that the fuel goes through the 10 mocron spin on filter before it goes through the 2 micron Racor filter?

Mike

[Ron Hill]

Mike : I found a Kohler 10 micron in line 3/8" filter and put it between the tank and the Racor fuel line.  I finally gave it up because it was too messy/smelly.  Did a good job, just impossible to change with out dripping diesel!!  Even tried a hemostat to clamp off the line!
Just make sure that any filter is specifically made for diesel - as gasoline filters will notwork!!   

[Ken Juul]

Last spring I pulled and cleaned the tank, changed all the filters etc.  Filled up adding Biobor as usual.  After burning about 3/4 of the tank, the engine started loosing power. Limped into port.  Upon pulling the Racor spin on the entire inner surface was coated in what looked like tea leaves.  Replaced the Racor, fueled back up.  About 10 hours later pulled the racor, interior looked good.  Ran it the rest of last year through at least one more tank of fuel.  In Nov when I was putting the boat away for the season I again saw some traces of crud in the filter, but the engine was still running strong.  I have not seen any water in the racor bowl either.  First point, BioBor works.  Turned the slime into hard particles that the filter trapped.  Second point the Racor works.  Shortly after I had the intial plugged filter I changed the engine mounted filter.  It was clean.  Third point, Murphy is out there.  Who would have thought the first tank of fuel I put into the clean tank would be contaminated.  Use Biobor or similiar at every refuel.

[Ron Hill]

Guys : Be cautious about the amount of Biobor that you use.  Over "Bioboring" is hard on the metal parts!!

[Stu Jackson]

We just changed our transmission fluid, primary filter and oil.

No bleeding required on the fuel side!!!!  Filled the new fuel filter bowl up with injector cleaner, ran like a clock with just the ignition switch ON to run the fuel pump.  Played with the knob a bit just for gins & giggles, but we really didn't need to do so after the first 15 seconds when the small amount of air went through.  Thanks again to Ken Heyman and Ron.  And to my friend and sailing buddy David Galson for his help (and cleanups!).

Racor R24S.

The inside of the Racor is a good indication of how dirty your fuel may have been, but remember, that's for the last six months or a year.  As long as you have no leaks, the pump's purring and the throttle is fine, the filter is doing its job!

[Martin1951]

We have the Racor 500 installed on our boat Aquabelle #218, about a month ago the engine turned over but didn't start. We finally got it running the next day , but didn't know what cuased it. 3 weeks ago we found a gap of air (1 in.) at the of the bulb. I changed the filter, it was covered in a blackish/brown coating. Filled it up and was fine for a couple of weeks . The other day we had about a 1/2" gap now . Ifilled it back up and it's been o.k. for a week. I've already tightened the clamps at the tank and the inlet connection. My next thought is tto swap out the fuel line, in case there is a slight crack in it and it is letting air in , especially during rough seas. Please any thoughts, are we on the right track of troubleshooting this. The engine by the way , has been running fine with these air gaps in the racor filter.  Thanks, Marty & Lil Conceicao  C34 #218

[Ron Hill]

Marty : Your boat is over 20years old so if you haven't changed out the fuel lines - now is the time to do it! 
Also check to make sure that your Racor filter gaskets are inplace and tight!   

[Martin1951]

Thanks Ron, We were told be the previous owner that all fuel lines were replaced in'2000.  I did check the 2 o-rings to make sure they were sitting o.kThanks for the info. Any other possible remedies would be appreciated. Marty & Lil  'Aquabelle'

[Jeff_McKinney]

Marty, Marty, Marty-

I hope you knew the PO really well and he provided some sort of proof as to that statement (like a reciept or a repair order ticket). Old aphorism: Trust but verify.

So now you have fuel lines that are at least 7 year old that may or may not be the source of a problem. When in doubt, change it out. 

[Ron Hill]

Marty : You can check your own fuel lines.  Look for the marking J1527 A1 marked on the line - that's the best USCG fuel line for diesel. 
I've used a lesser grade Gates brand fuel line in the past.  The only difference is the amount of time an open flame takes before it burns thru that line (5 vrs 15 minutes).
The real key is to look at a 90 degree bend in the line or make it bend that much.  If you see cracks in the outer jacket - it's time for some new fuel line!!    

[Martin1951]

Thanks Guys for the reinforced information.  I will do just that and swap out that fuel line. The PO did leave me a 'spare' starter, that when I had it tested, it turned out to be crap. I let you know how we made out.   Thanks again.  Marty & Lil   Aquabelle #218.