Replacing Racor Fuel Filters

How often, and under what conditions or circumstances should Racor fuel filters/water separators (e.g., Racor 900FH) be periodically replaced? It is based upon the passage of time? The number of engine hours?

If I buy a used boat with 6,000 - 7,000 hours on the engine and it has a single Racor 900FH at each of its two fuel tanks, how do I determine whether or not the fuel filters need to be or should be replaced?

Same question regarding the Racor fuel filter on the diesel generator.

Thank you for whatever insight, experience, and recommendations you have to share.

Boilermaker75 said:

How often, and under what conditions or circumstances should Racor fuel filters/water separators (e.g., Racor 900FH) be periodically replaced? It is based upon the passage of time? The number of engine hours?

If I buy a used boat with 6,000 - 7,000 hours on the engine and it has a single Racor 900FH at each of its two fuel tanks, how do I determine whether or not the fuel filters need to be or should be replaced?

Same question regarding the Racor fuel filter on the diesel generator.

Thank you for whatever insight, experience, and recommendations you have to share.

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IMO - the best way is to replace them when the vacuum reading shows that the filter(s) is loaded up and near the end of its useful life and requires replacing.
If you have a vacuum gage what does it read? If you do not have a vacuum gage consider adding one.
Some good reading on the topic here....
https://www.sbmar.com/articles/marine-fuel-filtration-the-seaboard-way/

I agree with Smitty; there are some generic recommendations on number of engine hours, but it doesn't compensate for reality in terms of the varying quality of fuels you fill the tanks with as you visit different fuel docks... or even if you use the same fuel dock. they could deliver different quality/cleanliness over time.
I've got a main vacuum gauge right at the Racors, and a secondary gauge up at the helm station so we can watch it while under way.
Secondly, if you have a glass bowl below the Racor; I shine a flashlight behind the glass (part of our startup checklist) and look for sediment/debris and water in the fuel. if it seems a bit dirty even if the vacuum gauge is ok, I'll go ahead and replace it.

They are cheap, why not once per year to 18 months? I have never seen a vacuum buildup and filters come out reasonably clean. A visual inspection gives a strong indication as to the health of your tanks and fuel.

B75, what engine does the vessel have?

Another consideration is the micron rating of the filter. Racors commonly are made in 2, 10 and 30 micron ratings. What you use comes down to personal choice. Lots of owners do a step down with a 30m racor first then either a 10 or 2 on the engine. I do it the other way because it’s easier to change the racor than changing the engine filter when I’m in a hurry. I have my 2m at the Racor, then a 10 on the engine. Yes, I have had my 2m start to clog and had to change it while underway, but I have two engines. There are arguments both ways. I agree with sunchaser. The filters are cheap.

It all depends on how much crap is in the fuel tanks. Go for a run in some chop and that will stir up anything on the bottom of the tanks. If you hear engine rpm wavering under a good load, it is time to change filters. Change them and see how much crap is in the pleats.

If a new to you boat, you have no idea how long they have been in there. Go ahead and change them now, then check them periodically.

My tanks are clean, but even then can hear some rpm fluctuations after about a year or a few hundred hours. New filter and all is well.

Pcpete said:

Another consideration is the micron rating of the filter. Racors commonly are made in 2, 10 and 30 micron ratings. What you use comes down to personal choice. Lots of owners do a step down with a 30m racor first then either a 10 or 2 on the engine. I do it the other way because it’s easier to change the racor than changing the engine filter when I’m in a hurry. I have my 2m at the Racor, then a 10 on the engine. Yes, I have had my 2m start to clog and had to change it while underway, but I have two engines. There are arguments both ways. I agree with sunchaser. The filters are cheap.

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"Yes, I have had my 2m start to clog and had to change it while underway, but I have two engines. There are arguments both ways."
There are no arguments in your Hino handbook, your Bayliner owners manual or the recommendation by Racor that you should use the 30 mic as the initial filter. FWIW - we have had no issues changing the on engine cartridge filters on the EH700 Hino's. Staged filtration will always remove more contaminants in total and your vacuum gages will allow you to manage the filter change for when it is convenient.

By all means if its a new to you boat and you don't know when they were changed last, change them right up front.
It's good practice so if you have to change one under "duress" you'll know how.
I change mine once per year even though my vacuum gages are still in the green.
You will find/develop a system once you start using the boat.

I also change mine annually as part of a spring routine. They are cheap and I'd rather do that at the dock then bouncing around in rough weather. So far, so good. YMMV

My 900 Racors are paired so I can change one while running. I change elements at about 500 hours. Gauge reads about 7" of hg at the change using 2 micron elements. My mains pump about 70 gallons an hour (burning 8+), so about 35,000 gallons have been thru the element.

All very helpful observations and suggestions, as always -- thanks to everyone.

In answer to Sunchaser's question, it's a single Ford Lehman 120 HP diesel engine, with (I believe) one Racor 900FH filter at each fuel tank. I don't know whether they are 2, 10, or 30 micron filters, however, nor do I know what sort of filter is on the engine itself or whether there are vacuum pressure gages in the engine compartment/room or at either of two helm stations.

You've given me many things to investigate and ask about during the marine survey and diesel engine inspection this Friday, May 17th. Thanks a boatload ;-)

Boilermaker75 said:

All very helpful observations and suggestions, as always -- thanks to everyone.

In answer to Sunchaser's question, it's a single Ford Lehman 120 HP diesel engine, with (I believe) one Racor 900FH filter at each fuel tank. I don't know whether they are 2, 10, or 30 micron filters, however, nor do I know what sort of filter is on the engine itself or whether there are vacuum pressure gages in the engine compartment/room or at either of two helm stations.

You've given me many things to investigate and ask about during the marine survey and diesel engine inspection this Friday, May 17th. Thanks a boatload ;-)

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A good general rule of thumb is to find out what the engine manufacturer recommends for filters. So if Lehman recommends a 30 micron primary filter with a 2 micron on-engine secondary filter, that is a good place to start.

dhays said:

A good general rule of thumb is to find out what the engine manufacturer recommends for filters. So if Lehman recommends a 30 micron primary filter with a 2 micron on-engine secondary filter, that is a good place to start.

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I am a bit out of the mainstream. Instead of the ubiquitous Racors, I have Davco filter housings. They have a clear bowl on TOP. When the fuel begins to reach the top of the bowl it is time to replace the filter. No vacuum gauges, no guesswork. I just yesterday changed filters (10 micron) after 300 hours on the job. Engines are Lehman 120s. Very easy to change filters with no mess to boot.

Change them now and you reset your clock. Absent a vacuum gauge and no history, change them when you next change the lube oil. Go from there based on what you find. If they look good next change after 2 lube oil changes. They are easy to change and not that expensive.

You said you are buying a boat. New to you, change the filters and take note. It is easy to add the vacuum gauges to the wing screw on top. The ones I recently bought have three indicators. One red one you set after you know at what approximate vacuum you need to change filters. One that follows the actual vacuum indicator needle and then stays behind and the vacuum indicator. This way you don’t have to go down in the engine room while under normal load. Just need to check them occasionally to see where the are maxing out. One interesting thing for me is that my vacuum doesn’t have a resting 0. They start out about 4 when attached and 0 only when removed. I buy a case of filters because if you have a real problem at sea you may need to change more than once.

I don’t fully get running 2 microns then 10 on the engines. I understand the reasoning for the 2 up front but then I’d put 2’s on the engines as well. No sense giving up the added filtration by having 10’s after 2’s.

As far as I have been able to find out the secondaries on my SP225s are between 5 to 7 micron and you can’t buy a specific micron like with a Racor. The manufacturers of the secondary filters don’t specify a micron rating as far as I could ever find. I use a 10 micron primary element in my Racors and then I don’t have to change the secondaries as often. My Racors are simple to change filters, the secondaries not so much.

Have Racor 1000 for my engine and change it annually. Also have a vacuum gauge at the helm for peace of mind. The 1000 series is rated for 180 GPH and my little John Deere only circulates 30 GPH, so I use the 2 micron elements based on the large surface area and slow flow rate. I view the filters on the engine as redundancy since the smallest is 2 micron. Yes, I change the engine filters annually also. In the relative cost of boating, changing fuel filters annually (<$50) doesn't even register.

Ted

Thank you again to everyone -- you've given me lots of questions to ask and information to gather/document.

The owner/seller claims to have replaced the fuel filters last October (2018), but I don't know how many hours have been put on the engine since then; hopefully, the owner/seller has a maintenance log I can examine during the marine survey/engine inspection this Friday.

I like the idea of immediately replacing them, so I "reset" the clock as of May 31st/June 1st, before leaving Carolina Beach, NC for Edgewater, MD.

I've asked the sales agent/broker to ask the owner/seller when (if ever) the fuel tanks were last cleaned out, but haven't heard yet.

Do any of the Ford Lehman 120 HP diesel engine owners happen to know what the manufacturer recommends in terms of primary filter microns (2, 10, 30)? and in terms of the fuel filter on the engine itself?

Greetings,
Mr. B. Whenever I do a filter change, either fuel (CAV filter) or oil, I mark the engine hours right on the filter housing. With my Racors, I depend on vacuum gauge readings regardless of hours or amount of fuel that they may have passed.


There is some controversy regarding progressive filtering but I run 2 micron in both the Racors AND the on engine CAV filters. As mentioned above, the Racor filter elements are much easier to change in a seaway if necessary.


I would suggest a store of spare filters as well as changing the existing ones. IF you run into any bumpy weather you will know soon enough how clean your fuel tanks are. Until then, I wouldn't worry about it.



Lehman 120's

The CAT dealer/service people recommended against 2 micron primaries so I use 10 micron. They are in twin RACOR 900’s with a vacuum gauge so I can monitor their performance. It is also worthwhile pulling the whole RACOR filter housing down and cleaning the bowl and the centre turbine occasionally. MarineHowto has the usual worthwhile and detailed explanation on a RACOR 500 here:

https://pbase.com/mainecruising/rebuilding_a_racor_&page=1

It is easier and not as messy out of the boat. You go through about 1/2 Gal of fuel on a 900 and it gets tossed. I use a fuel resistant liquid thread sealer on bottom drain plug as well. I have had one leak past the gasket and it is really annoying when you have just refilled it.

Top tip: special order a 5’ piece of 5” pvc pipe, cut a finger slot in the side, screw it to the ceiling of your engineroom and use it to store your spare filters.

I change mine whenever I change engine oil. They are always clean although the fuel I drain off is generally murky. I have never experienced symptoms of clogged filters including any variance in the pressure readings. My boat is old although my tanks have been refurbished within the last 10 years.

pete

I change my 2 micron element when the vacuume gauge lifts off "0"

Takes about 1 1/2 years.

syjos said:

I change my 2 micron element when the vacuume gauge lifts off "0"

Takes about 1 1/2 years.

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Any vacuum gage should read higher than "0" when a new filter is installed between the filter and plumbing resistance.

Both gauges read "0" with new elements. Maybe at the high edge of the "0" line.

RT Firefly said:

Greetings,

There is some controversy regarding progressive filtering but I run 2 micron in both the Racors AND the on engine CAV filters. As mentioned above, the Racor filter elements are much easier to change in a seaway if necessary.

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RTF, where do you find 2 micron CAV secondary filters? Inquiring minds want to know.

I looked a couple of years ago and could not find a listing on the micron size of CAV filters. The best I could get was Bob Smith saying he thought they were about 5 to 7 micron.

Change once per year regardless of number of hours including inactive filter if dual racor.

Favor Filters

My GB 36 had 7000 hrs on the motor when I bought it. I had a full service done on it including filters. Each year I have a 100 hr svc done on engine, xmission and gen. I also replace the Racor filters. I’m at 7500 hrs now and so far, so good.

Replacing RACORs

Regardless of the micron value of primary and secondary fuel filters that you determine best, a key element is how much vacuum your fuel pump has to pull to get fuel thru your filters. My diesel guy says that filtration is nice but having the pump die early because you made it work too hard is more important. With that advice, I changed filters to reduce the vacuum and perhaps avoided a pump failure!