Racor Leak

[Sandero]

Shiva has a pair of racor filters with a selector valve so that the fuel can pass through one or the other. The logic being that if one filter gets clogged I can divert the fuel through the clean filter then replace the fouled one and so forth. This was an after market upgrade.

I have two questions and one involves a leak which seems to have developed.

1. The system was installed so that the fuel from the tank enters both filters and the diverter valve is connected to the two filters and selects which one will be used to send the fuel on to the primary engine filter.

There is an alternate way to plumb this which would be to have the diverter on the input side of the tworacors and select which one receives fuel from the tank sending it on the primary. This isolates one or the other filter... But would this lead to potential air locks?

2. I discovered a leak at the very bottom of one of the racors. Leaks travel down and so it could be a very tiny leak and simply flowing to thew bottom... or it could be a screw at the bottom which is apparently is used to drain the filter bowl is leaking. It's plastic and I am hesitant to apply too much pressure in tightening it.

I am planning to take the entire thing apart this fall and replumb it... perhaps moving the diverter valve to the input side instead of the output side as it is now. Had it been plumbed to the input side a leaky filter could be isolated and the leak stopped. But plumbed as it presently is.. there is no way to prevent fuel from finding its way to the beached area.

Questions:

1. Can the drain screw be tightened? (I tried and it still seems to leak)
2. Should the drain screw be replaced? With a brass one???
3. Should the entire filter be replaced if the leak is at the drain screw?
4. Should I replumb with the diverter valve on the inflow side?

[Ziggy]

1. To properly isolate the filters for replacing one without airleaks, I think you should have two 3-port valves, one upstream, one downstream of the filter assembly.
2. I also had a fuel leak and I was not able to stop it by tightening the drain screw. Racor makes a filter rebuild kit, which includes all the gaskets. Replacing all the gaskets cured the leak for me.
3. I replaced the drain screw with a cock valve. I still put a plug in the valve outlet in case it leaks. But this eliminates the need to periodically loosen the drain screw, which may have caused the leak I had.

[KDH]

The plastic screw at the bottom of our racor was replaced last year after a small leak turned into a steady drizzle of fuel. You can tighten the screw and that will take care of the leak for a time. Our new plastic screw is now starting to drip a tiny bit. As I foolishly did not order more than one, my solution is to place a stainless steel bowl (velcroed in place) under the racor with a piece of 3M boat "diaper" in the bottom of the bowl. Hopefully, this will hold the problem at bay until we get somewhere with an actual boat chandlery.

[Sandero]

Thanks for the replies.

Do you think a brass or stainless drain screw will solve this?

Adding a valve on the input side is no problem.

Why was it placed on the output side by the mechanic who installed it?

[Ziggy]

Originally Posted by defjef

Thanks for the replies.

Do you think a brass or stainless drain screw will solve this?

Adding a valve on the input side is no problem.

Why was it placed on the output side by the mechanic who installed it?

I think the leak is caused by a worn or damaged gasket. With a stainless or brass screw you might be tempted to continue to tighten it until you crack the glass bowl.

A single valve on the output side is sufficient to isolate the filter from the engine. With a valve on the input side only the fuel pump would suck air when one of the filters was opened for replacement. But a single output side valve does not completely isolate the filter, and could still allow air to get in.

[Ziggy]

Defjef,
Check out marinefilters.com. They have excellent prices for filter elements and spare parts, including gasket kits, the drain valve I mentioned, etc.

[captain58sailin]

When I plumbed in my dual racor system, which was of my own construction from parts I already had + a couple of manifolds, I put the 3 way valve on the supply side of the fuel flow. Every other vessel I have owned or operated from 32' gillnetters to 260' Frac vessels have the fuel 3 way valves on the supply side of the fuel flow. You can put a shutoff valve on the down stream side of the of the manifold, I just don't know why you would need one. You have the shut off coming out of the tank, and the diverter valve at the fuel filter, the only fuel that you are dealing with on the filter that is shut off is what is contained in the filter housing. With this configuration you can isolate each filter housing should you encounter a leak problem on one of the canisters. Like the other posters, I put a small ball valve in the bottom of the filter housing to eliminate the need of the plastic screw unit, that seems to be the weak link in the racor system, there always seems to be a problem with the bottom of the bowl leaking.

[Sandero]

Thanks to all who commented. I think I will get ball valves to replace the plastic nut and a couple of repair kits w/ gaskets... and re plumb with the 3 way valve on the input side of the filters.

[Ziggy]

Originally Posted by defjef

Thanks to all who commented. I think I will get ball valves to replace the plastic nut and a couple of repair kits w/ gaskets... and re plumb with the 3 way valve on the input side of the filters.

I think should also keep the valve on the output side. Two valves will allow you to completely isolate one filter and replace the cartridge with the engine running, without introducing air in the fuel line.

[captain58sailin]

What I neglected to mention is that I have a ball valve on the out flow side of the manifold, one that goes to the main engine and the other that goes to the gen set, these are set in the manifold so that fuel can be shut off to either appliance, if you have a 3 way valve on the supply side of the manifold and you switch from one to the other racor, there is no way for air to enter into the system unless you empty the racor and switch the valve back to the empty racor.

[Ziggy]

Originally Posted by captain58sailin

What I neglected to mention is that I have a ball valve on the out flow side of the manifold, one that goes to the main engine and the other that goes to the gen set, these are set in the manifold so that fuel can be shut off to either appliance, if you have a 3 way valve on the supply side of the manifold and you switch from one to the other racor, there is no way for air to enter into the system unless you empty the racor and switch the valve back to the empty racor.

Sorry, but I still don't understand how you can change a filter cartridge with the engine running. From your description it seems like you can shut off the fuel flow to the engine completely, but you can't isolate one filter from the other. Am I missing something?

[captain58sailin]

Yes, where the fuel comes into the manifold there is a 3 way valve so when you switch the valve you are either suppliing one fuel filter housing or the other and the one not being supplied is blanked off by the valve position. I am looking for my drawings and I'll see if I can attach it to a post, I have never done that, but will give it a try. I don't have photos of it on my computer or I would just post them.

[Roy M]

I, too, have the Racor filter setup you describe, with three-way valves above and below the filters. The output then goes to a 2micron Racor, since my engine filter is against the centerboard trunk, and a real drag to service. Before the fuel line gets to the injector pump, I have teed off to a Racor vacuum gauge located in the cockpit instrument panel to give me a heads-up if there is a developing problem. Also, located in the back of the gauge is a Racor vacuum switch, which sets off an audible alarm and an indicator lamp above the vacuum gauge. I hate clogged fuel filters. I, also, had the leak issues at first, but going through everything and tightening did the trick.

[captain58sailin]

I am having a problem attaching my drawings, my system is the same setup as described by Roy M, there are (2) 3 way valves one on the supply side and one on the discharge side. I gave out incomplete information, my apologies for giving out confusing information. I have incorperated 2 vacuum gages, one on the manifold and then one on the instrument panel on the bridge.

[Ziggy]

OK, it seems you have essentailly the same setup I was recommending to defjef. I think we're all on the same page.