Racor Filter Replacement

When you change a racor filter for a Ford Lehman 120 is it necessary to bleed the system after you replace the filter?

If you make sure that the body of the Racor is full of diesel after you replace the filter, you shouldn't have to bleed. I have a 120 Lehman and don't have a problem.

The only time I bleed the system is after I replace the on-engine filters.

mike

Thanks. I used to be able to pay someone to do it when I had other work done. No mas...

Islanddreamer is correct. Be sure to turn off fuel to tank line so fuel doesn't drain back into Racor.
Also, bleeding the FL 120 is dead simple and quick, one bolt, a few strokes on the fuel pump and you are good to go.
It is good to practice this at the dock so you know how if you need to do it underway.
Arch

Arch said:

Islanddreamer is correct. Be sure to turn off fuel to tank line so fuel doesn't drain back into Racor.
Arch

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I have never shut off the fuel, ,never had a problem with drain-back.

jleonard said:

I have never shut off the fuel, ,never had a problem with drain-back.

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I would imagine that would depend on the relative heights of the fuel tank and filter.

jleonard said:

I have never shut off the fuel, ,never had a problem with drain-back.

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Probably just the way mine is set up. Has happened to me so I've gotten into the habit of isolating the filter I'm working on.

Arch

dhays said:

I would imagine that would depend on the relative heights of the fuel tank and filter.

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Yes. If I don't shut off the fuel valve the filter will overflow into the bilge. However, once I'm finished replacing the element I can let gravity re-fill it. I have CAV on engine filters as well and I added the ABC CAV filter adapter so it can use screw on filters. Worth every penny.

Egregious said:

Yes. If I don't shut off the fuel valve the filter will overflow into the bilge. However, once I'm finished replacing the element I can let gravity re-fill it. I have CAV on engine filters as well and I added the ABC CAV filter adapter so it can use screw on filters. Worth every penny.

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I cleaned out my Racors a couple weeks ago. It was pretty surprising how much crud I found hiding at the bottom of the bowl. Impossible to see until I took the metal heat shield off and dissembled the bowl. Anyway, I found that if I transferred fuel to one tank so it was almost full, and was patient enough, gravity would fill up the Racors after the new filters were put in. In the past, I didn't think this worked that well for me, but with a full tank and enough patience, it worked just great.

Never shut the fuel off here either. Just made certain there was plenty of diesel in the Racor before I closed it up. Level should be at the top, and a little coming from around the brass handle as you secure it.

Islanddreamer said:

Never shut the fuel off here either. Just made certain there was plenty of diesel in the Racor before I closed it up. Level should be at the top, and a little coming from around the brass handle as you secure it.

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There is no need to refill them that high. Within a 1/2" to 1/4" from the top is fine.

Capt.Bill11 said:

There is no need to refill them that high. Within a 1/2" to 1/4" from the top is fine.

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That is true and I have left a 1/2" air gap a lot in the past. I am happier when it is filled to the brim however. I'm not sure it makes a difference but it makes me feel better.

Here is a quote that is from an article that I read a few months ago. I found it helpful to me with my limited understanding of fuel filtration.

Assuming that your system is airtight and that aeration of the fuel is not a problem, then changing the filter remains the only way to introduce air. Some would have you believe that unless you fill the filter to the absolute top, you risk drawing air into your engine, and that is not true. Remember that a tube inside the filter creates the suction that pulls fuel through the element. As long as the fuel level remains above this pick up point, no air will get into the engine.

On a 900 series filter, that spot is about 4 inches below the lid–even if you only have fuel within 2 inches of the top, air will not be drawn in. In boatyards we often replace elements that show contamination from the bottom to within 2 to 3 inches of the top, and which look unused above that mark. This scenario typically arises when the last person who replaced the filter element failed to add fuel to the top. No additional air entered, and the upper portion of the filter remained unused. Cover the replacement filter with fuel, but you need not fill it to the brim. On smaller filters, however, the margin for error is less: On the 500 series, the pick up point is only about one inch below the top of the filter.

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In the past on may sailboat, it was next to impossible to fill up the Racor filter. When changing it, I would see a good 1/2" of unused filter at the top. I figure is the fuel fills the canister, I am using all of the cartridge.

BTW, I dug up an older thread that I thought was helpful, particularly this post by Howard.

hmason said:

Given my curious nature, today I called Parker Filtration, the mfg of Racor. They said, on a dual setup, run one filter until it clogs or for a year, then switch to the second filter and change out the used one. I specifically asked them if a new filter sitting in diesel fuel for a year is compromised in any way and they said absolutely not. Then I asked about the water blocking properties of the filter and they assured me that it remains intact even though it is sitting in fuel for up to 2-years.



Howard

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On my duals this is what I now do. Granted I have only owned my boat for a year and I just now cleaned out both filters, disassembling the bowl etc... When I did that, I had one spare filter so I re-used the filter that has been sitting idle for the past year and replaced the one that I have used. I now have each labeled with the date they were replaced. I am now using the 1 year old filter. Next year, I will replace it and start to use the filter that I just replaced. In this way, I will replace one filter per year, saving a tiny bit of cash and a few minutes.

Another reason I love my Detroit

I put a squeeze bulb circuit on mine with qtr turn mini valves. I can change a filter while underway in less than fifteen seconds.

Have you ever done that? Had to change filters underway?

Choices said:

I put a squeeze bulb circuit on mine with qtr turn mini valves. I can change a filter while underway in less than fifteen seconds.

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Only once. I knew it was getting clogged. But rpm dropped about 300 as I was coming in the jetties, so I spun around and went out a couple miles and changed it.

Yes. On three different boats. In heavy weather with no place to hide.

catalinajack said:

Have you ever done that? Had to change filters underway?

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Just wondering but did you have vacuum gauges and, if so, in what condition were those filters in before you left port?

Portage_Bay said:

Yes. On three different boats. In heavy weather with no place to hide.

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catalinajack said:

Have you ever done that? Had to change filters underway?

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catalinajack said:

Just wondering but did you have vacuum gauges and, if so, in what condition were those filters in before you left port?

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Boat #1. "My" boat during much of my career. I took excellent care of that boat. She had Isuzu 4BD1 powered gen sets. With Baldwin spin ons and OEM block mounted filters. No vacuum gauges. Baldwin and OEM filters routinely changed as a maintenance item. Not cut open and inspected at change. The main engine Cat D379 had Racor 1000 duals with vacuum gauges running 2 micron filters. Vacuum was good, bowls were clean. As Lepke points out, if your engine moves a lot more than it burns you are constantly polishing the fuel. Gens should have been seeing clean fuel. Must have been some crud in the fuel taken on before departure. The reason to change filers on the gens was that the boat required 480 3 phase for electric / hydraulic steering. I put the mate at the manual wheel making for the Columbia River about 40 miles away. That's on 65 ft, 87 tons displacement in heavy weather. Good thing he was a stout young lad. I was in the engine room. Change filters on #1, barely get it up and running and #2 dies. Lather, rinse, repeat. Worth noting is that the boat has skin tanks, sloped fore / aft and athwartships creating a deep 'pocket' in the aft centerline corner where the pick up for a hand stripping pump was placed. Also inspection hatches big enough to enter the tanks for cleaning which happened on a bi annual schedule. Never found more crud than could be taken care of with a few rags every time.

Boat #2. OA Mk1, Racor dual 900. It was a delivery and I don't recall if there were vacuum gauges. Everything looked good on departure but as we neared Morro Bay we started having problems. Water and crud. We drained bowls and changed filters the whole way from San Diego to La Conner Wa. Sometimes in heavy weather. Stopping at Morro, Monterey and Crescent City for supplies.

Boat #3. Sailing as relief capt with an engineer. I don't know the status of the filters, tanks or fuel. I do know the engineer constantly battled the problem to keep the main running.

So, yeah, it happens. Changing filters underway. Far less likely if it's your own boat and you take good care of her. But still, it happens. I know of an instance where a very well cared for boat lost power due to plugged filters crossing the Columbia River bar. To not be prepared for a quick filter change is a chance I won't take.

One way to make it easy is dual Racors, run on one, the other in reserve. Never need to shut down. Refill the filter to near the top if need be before putting the lid back on. You won't need to prime or bleed the system. I know many will disagree but I run bigger than required Racors with 2 micron elements. That way I NEVER need to change the block mounted filters underway. Which on some engines is not easy and on most will require priming and bleeding, the last thing I want to do while dead in the water getting tossed around in the engine room.

No disrespect intended, but those old stories of clogged filters are not relevant to those of us buying our fuel in the US or Canada, and likely all of Europe and SE Asia.
Our fuel meets current standards for Sulphur content, ie not to exceed 5ppm, whie the fuel of 20 and more years ago, when the events described in the anecdotes occurred, was not required to meet those standards. That changed over a couple of steps, first down to 15 ppm, then to 5 ppm. Having clean fuel essentially eliminates clogged filters, no matter how it is accomplished. Nowadays, that is accomplished before we buy it, so all we need to do on our boats is keep it that way. A far easier task. Many now go several years between filter changes, without incident.

No disrespect taken, please don't take my further comments as disrespect. Two of my three experience were in the last TWO years fueling out of US Sand Diego and Anacortes Wa.

koliver said:

No disrespect intended, but those old stories of clogged filters are not relevant to those of us buying our fuel in the US or Canada, and likely all of Europe and SE Asia.
Our fuel meets current standards for Sulphur content, ie not to exceed 5ppm, whie the fuel of 20 and more years ago, when the events described in the anecdotes occurred, was not required to meet those standards. That changed over a couple of steps, first down to 15 ppm, then to 5 ppm. Having clean fuel essentially eliminates clogged filters, no matter how it is accomplished. Nowadays, that is accomplished before we buy it, so all we need to do on our boats is keep it that way. A far easier task. Many now go several years between filter changes, without incident.

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I get 4 miles to a gallon, so I don't move much fuel.

Was hoping to make Appalachi, but made Governed Cut.

Vacuum gauges with tell tales told the story.