Does water ruin racor?

[gwp]

Will a little water ruin a new racor filter or the secondary filter? Biocide always in tank. Thanks

[Ken Juul]

Need more specifics to correctly answer your question...but I'll take a shot.  The Racor is design to separate water from the fuel.  The fuel comes in the top, goes to the bottom and is filtered on the way up.  The 180° turn is supposed to cause the water to separate and stay in the clear bowl on the bottom.  If it has made it to the secondary something is wrong.  If you mean you left both filters out in the rain before install.  Then no, don't use them.

[gwp]

Thanks Ken,
To avoid giving a bunch of extraneous info, I'm probably oversimplifying the question. When my diesel fill cap developed a crack, got some water in a very clean tank, with very new filters. Pumped out all the fuel and replaced, realizing that one can not pump the tank completely empty using the fuel pump. So my question is.....given that some water has passed thru the filters, does that deem them no longer good? Thanks

[Ron Hill]

gwp : Here's what I'd do to get that water separated and out of the fuel tank :

Take your fuel bleed valve and open it all the way and turn on the key switch (battery ON).  That way the electric fuel pump will circulate the fuel thru the Racor filter and separate out the water. I'd leave it run about 5 to 10 minutes. 
Look at the plastic bowl of the Racor pump assembly(on the bottom of the screw on filter) and there is knurled knob on the bottom.  After that fuel pump run, open that knob and drain some fuel into a small glass jar and look to see if there is any water.  The water is heavier than diesel and it will be quite evident!!  After running the engine a few (10?) hours, do the same drain and recheck. 

Turn the valve bleed valve OFF and then crack it open about 1/4 to 1/2 turn open.  The electric fuel pump will run a bit faster, but you will have a self-bleeding system and circulate more fuel thru the Racor (to catch any residual water).

Be sure to use some Water Zorb by MDR to treat your fuel (Defender).  I'd stay away from any water absorber that has alcohol in it.

Your next project should be to change your fuel fill to one that has a metal cap!!  Many articles and posts on that very topic.  The plastic caps will and DO crack - as you've found out!!

A few thoughts

[Ted Pounds]

The short answer is "no".  Water wont pass through the primary filter.  If get enough water in there it will clog the filter and stop the engine.  Then the filter definitely needs replacing.  One reason the filter is there is that there's probably always some amount of water in the tank, however small.  That's also why you add the biocide.

[gwp]

Thx. never thought if this technique of filtering. Great idea. I would appreciate someone explaining exactly what the bleed knob does and how it is to be used. I've always thougt it was in lieu of loosening the injector nut but don't understand why only air can comes out and never any diesel?

[Ken Juul]

if you look at the top picture at the bottom of the link you will see where to look.  The knurled knob is very easy to find then.


http://www.marinedieseldirect.com/universal/200157/universal-owners-manual-m25xp-specifications.html

[Stu Jackson]

Bleeding 101    http://c34.org/bbs/index.php/topic,6377.0.html

[gwp]

Have now graduated from bleeding 101...Very helpful info. However, still don't understand why diesel doesn't escape thru bleed knob once air is evacuated. Thanks for the help!

[Stu Jackson]

However, still don't understand why diesel doesn't escape thru bleed knob once air is evacuated.

Because it is a closed system.  Unless the bleed knob is broken.  Either fuel or air goes thru it.  Think of it like a faucet when your water tank goes dry:  first you get water, then air, but the faucet itself doesn't leak.

What the knob does is let the air go THROUGH the system, from wherever the air was introduced (i.e., new fuel filter), through the fuel hoses and then back via the fuel return line to the tank, which is what the fuel does when there's no air in the system.

[mainesail]

The short answer is "no".  Water wont pass through the primary filter.  If get enough water in there it will clog the filter and stop the engine.  Then the filter definitely needs replacing.  One reason the filter is there is that there's probably always some amount of water in the tank, however small.  That's also why you add the biocide.

This is not true. I have had at least three customers get so much water in the tanks that water made it to the injectors and shut the engine down, billowing white smoke ensued right before it sputtered and died. Both primary and secondary filters were chuck full of water. On the Perkins when I cracked the injectors a diesel/water mix came out (bleeding Perkins 4-108's is a crappy job). That boat had a Racor 120 as Primary and a spin on Fleet Guard as secondary.

In every event the deck fill cap was the culprit and in all cases it was the primary Racor filters that let the water by to the secondary. If you don't notice it before the bowl gets full then the pump can suck it through the filter media..

Water can eventually lead to damaging/softening of the filter media. The best course of action is to get all the water out of the tank by sticking a probe all the way to the bottom and sucking it out. Better yet remove all the fuel into Jerry jugs and physically dry the tank bottom by using a microfiber rag on a stick. This can be done through the fuel sending unit hole on many tanks. Then replace both filters and fill with fresh fuel..

I have a home made pump I use just for this purpose. Seems to happen more regularly than we'd like to believe... Change those o-rings regularly and ditch the plastic lid diesel fills.....

[gwp]

Got it. The air/fuel is vented into the return line. I thought it vented thru the bleed screw itself. That makes sense. Nice outfit you have there mainesail. I wil replace filters just to be on safe side. Thx much