Fuel Filter Gauges - Necessary or Not?

[wrwakefield]

Originally Posted by Wotname

First a short background.

I have never had a gauge on my fuel filter and never felt the need for one.
I note that many on CF do have them and some sing praises to these gauges.
I get that on big engines (say > 60 or 80 hp), they could be quite useful.

But what is everyone's take on such gauges on small engines (say < 40 hp)?

Do they really foreshadow looming filter problems or just tell you that right now, the filter is clogged - you know, just after the engine is coughing or has died from file starvation!

And if they are so good, what is better. A differential gauge across the filter or an absolute gauge on the output side of the filter? I can see theoretical reasons for both methods but I have no experience with such matters.

The poll is multiple answer so feel free to tick as many as you feel best describes your viewpoint.

I see you already received a lot of excellent feedback from those with first-hand experience.

Answering your one question:

Do they really foreshadow looming filter problems?

Yes- because they tell you how hard the fuel pump is sucking to pull fuel through the filter and associated lines and fittings. As a filter gradually clogs, the vacuum reading increases (this could be over a period of hours, days, weeks, even months.) I change filters based upon that reading. [When it approaches -5"Hg or more...]

It won't give you much forewarning if you have a sudden clog as you probably won't notice the vacuum gauge spiking before you notice the engine failing...

Therefore, keeping the tank(s) and fuel clean is paramount. The vacuum gauge is just an early warning system for clean fuel.

Our boat is set up with 2 Racor 500s with 1 vacuum gauge between them. With the flip of a valve we can switch between filters so if one plugs suddenly, we can switch to a clean filter while we change out the plugged one. While this is nice to keep you going [if you have enough filters...] its no cure for a fouled fuel system.

I agree with DeepFrz that the gauges with a telltale are best as they don't require live readings. On my future projects list is running a line into our pilothouse from the engine room to add a 2nd vacuum gauge to the instrument cluster. [The current gauge is in the engine room, and is logged during our ~hourly engine room inspections when motoring....]

In the end, you have to decide whether you want to know the state of your fuel filter(s) with an indicator other than the engine...

Cheers!

Bill

[jhstacy]

if I dont watch that guage, my engine gets shut down at the most inopportune times. Less than 4 PSI and I'm good to go.

[skipmac]

Originally Posted by jhulmer

On one particular run the route to the back bay was rough and I assume the fuel tank had enough particles in it to clog the 2 micron filter, which it did, and we couldn't get full power. we managed with what we had under the circumstances. Unfortunately, we damaged the injector pump in the process. Cost us about $800.00 to have it repaired.

Curious as to how the injector pump was damaged. If the filter clogged it would restrict fuel flow to the pump but unless the filter ruptured and passed dirt to the pump I don't understand how it was damaged by limited fuel supply.

[Hudson Force]

I posted that I do not have a fuel vacuum gauge and That I would find one useful. "Useful" in that I would always find more diagnostic information useful, but I do not think that I'll install one. I have put 6,782 hours on my current Yanmar 4JH3E and I've never had a stall from a clogged fuel filter. I do run with two parallel Racor 500s, but I've also never been required to switch from one to another due to a clogged filter. I will admit to switching after sucking air into one of the improperly sealed Racors once, - my stupid error with an O-ring!

If I did add the gauge, then I would want it to be present where I could see it at my helm and this would require about a 3.5 foot length of vacuum hose from the position of my Racors. Are there any opinions among the group about problems with the length of vacuum hose?

[Capt Gill]

Originally Posted by Roy M

I have had the delightful experience of having the engine RPM's suddenly rise and collapse, indicating a fouled fuel filter. I've had it too many times, generally at a most inconvenient moment, for example, entering a narrow channel in foul weather with following seas. On my own boat I have a vacuum gauge installed in the cockpit, alongside all the other important gauges. I even have a Racor vacuum switch installed in the line, with a piezoelectric buzzer and a red LED above the vacuum switch, just in case I'm totally out of it (or asleep with a novice crew at the helm). The vacuum switch and gauge indicate when things are clean and happy, when things might be getting "iffy" and when things are about to go terribly badly. I hate surprises with the fuel, especially when making a final approach in less than ideal conditions. P.S., the amber LED above the vacuum gauge is for the Racor water sensor, just in case the filter has failed to remove all of the possible water in the fuel. I also have a parallel fuel filter so, if the buzzer and light(s) go on, I can instantly switch to a clean fuel filter and take care of the problem later. Oh, and by the way, some of those incidents with fouled fuel filters looked like liquid mud when the filter was extracted. It's a real eye-opener (or mud in your eye).

I like your setup. I presently have the standard optional Racor gauge that mounts on top of the filter assy. for my Perkins 4.108M(50hp). Like you,I believe it's important info right after o/press and eng. temp. (either coolant or oil). What's holding me back is that running about three meters of tubing to the c/pit eng. panel introduces the possibility of a vacuum leak (Murphy's Law) defeating the idea if it happens. So, I'm waiting (due to backlog of higher priorities)to locate a electrical sensor/gauge unit and a settable on/off sensor for an idiot light.
For those who say they don't need one because of regular maint., dual filters + be reminded that stuff happens at irregular times and dual filters won't remedy a before filter restriction or give you any helpful diagnostic info.
Please post if anyone knows where to source the above.

[GrahamHO]

Originally Posted by Wotname

First a short background.

I have never had a gauge on my fuel filter and never felt the need for one.
I note that many on CF do have them and some sing praises to these gauges.
I get that on big engines (say > 60 or 80 hp), they could be quite useful.

But what is everyone's take on such gauges on small engines (say < 40 hp)?

Do they really foreshadow looming filter problems or just tell you that right now, the filter is clogged - you know, just after the engine is coughing or has died from file starvation!

And if they are so good, what is better. A differential gauge across the filter or an absolute gauge on the output side of the filter? I can see theoretical reasons for both methods but I have no experience with such matters.

The poll is multiple answer so feel free to tick as many as you feel best describes your viewpoint.

In 46 years of owning yachts with motors, I've never had a fuel problem. I buy my fuel from vehicle service stations which usually have a big turnover of fuel as with my present 20 HP motor I get it in plastic fuel "cans" and my tank is only 30 litres. I try to keep my tank as full as practical. I protect the filler from water intrusion. I change my filters every year and at the same time drain some fuel from the bottom of the tank. I carry spare filter elements. My fuel pickup is from a couple of inches above tank bottom. For me a pressure gauge would be something else to go wrong. KISS


A few years ago locally at my marina there was a problem with some fuel possibly bought from a nearby floating marine station. It never affected me fortunately.


I can see that with bigger vessels possibly fuelling at dubious locations a gauge could be useful. My guess, only, is that a differential gauge might be better but that theoretically could show variations depending on the tank fuel level if the tank is higher.


How many instruments do we have on today's cars? Often speed, revs, fuel contents only. How often do our filters block?


Being able to buy fuel in containers helps as you can visually check it and it's sealed from the atmosphere. Also in more remote locations it's often easier to refuel.


I think the answer is "It depends"

[Wotname]

First and foremost, thanks again to everyone who took the time and interest to either vote or post. You are all helpful in formulating my next thoughts on this subject.


The following quotes are not in any special order or necessarily "better" than the non-quoted posts, they are just highlights that resonated with me.

Originally Posted by Cheechako

I think it depends. I have had them and not had them. Frankly I never looked at it. It depends on how well you know your whole fuel system. If you have a clean tank, know how it is all constructed, clean fuel and maintain the system, you don't need one. If yo have an old boat, old tank, messy fuel etc, you can have one and it will help tell you why your engine wont run... but it wont make your engine run!

If only they where the magic bullet

Originally Posted by ontherocks83

If nothing else it is a great diag tool especially if it has a tell tale or shadow needle, what ever you want to call it. If your engine dies, then looking at the gauge will tell you instantly if it is a problem in between the tank and the gauge or not.

I'd rather know I have or don't have a fuel restriction problem with one glance then have to diagnose it. If the gauge reads perfect then you know to look else where and not waste your time.

I get that this is pretty helpful!

Originally Posted by Hudson Force

I posted that I do not have a fuel vacuum gauge and That I would find one useful. "Useful" in that I would always find more diagnostic information useful, but I do not think that I'll install one. I have put 6,782 hours on my current Yanmar 4JH3E and I've never had a stall from a clogged fuel filter. I do run with two parallel Racor 500s, but I've also never been required to switch from one to another due to a clogged filter. I will admit to switching after sucking air into one of the improperly sealed Racors once, - my stupid error with an O-ring!

If I did add the gauge, then I would want it to be present where I could see it at my helm and this would require about a 3.5 foot length of vacuum hose from the position of my Racors. Are there any opinions among the group about problems with the length of vacuum hose?

It depends on one's workmanship and attention to detail IMO; excellent vacuum hose and well protected must be OK but it does go against the KISS principle.
I am going to investigate electrical options!

Originally Posted by Capt Gill

I like your setup. I presently have the standard optional Racor gauge that mounts on top of the filter assy. for my Perkins 4.108M(50hp). Like you,I believe it's important info right after o/press and eng. temp. (either coolant or oil). What's holding me back is that running about three meters of tubing to the c/pit eng. panel introduces the possibility of a vacuum leak (Murphy's Law) defeating the idea if it happens. So, I'm waiting (due to backlog of higher priorities)to locate a electrical sensor/gauge unit and a settable on/off sensor for an idiot light.
For those who say they don't need one because of regular maint., dual filters + be reminded that stuff happens at irregular times and dual filters won't remedy a before filter restriction or give you any helpful diagnostic info.
Please post if anyone knows where to source the above.

Yes, I like the electrical solution and this comes from one who is usually "anti-electronic solution" but I can see that having an electrical pressure transducer is more in keeping with the KISS of fuel delivery. Any failure of the electrical side of the solution is not engine critical.

Originally Posted by GrahamHO

In 46 years of owning yachts with motors, I've never had a fuel problem. I buy my fuel from vehicle service stations which usually have a big turnover of fuel as with my present 20 HP motor I get it in plastic fuel "cans" and my tank is only 30 litres. I try to keep my tank as full as practical. I protect the filler from water intrusion. I change my filters every year and at the same time drain some fuel from the bottom of the tank. I carry spare filter elements. My fuel pickup is from a couple of inches above tank bottom. For me a pressure gauge would be something else to go wrong. KISS


A few years ago locally at my marina there was a problem with some fuel possibly bought from a nearby floating marine station. It never affected me fortunately.


I can see that with bigger vessels possibly fuelling at dubious locations a gauge could be useful. My guess, only, is that a differential gauge might be better but that theoretically could show variations depending on the tank fuel level if the tank is higher.


How many instruments do we have on today's cars? Often speed, revs, fuel contents only. How often do our filters block?


Being able to buy fuel in containers helps as you can visually check it and it's sealed from the atmosphere. Also in more remote locations it's often easier to refuel.


I think the answer is "It depends"

Yes, I think so and the poll results back that up IMO.

[Wotname]

Originally Posted by Capt Gill

……... What's holding me back is that running about three meters of tubing to the c/pit eng. panel introduces the possibility of a vacuum leak (Murphy's Law) defeating the idea if it happens. So, I'm waiting (due to backlog of higher priorities)to locate a electrical sensor/gauge unit and a settable on/off sensor for an idiot light.
……….
Please post if anyone knows where to source the above.

Originally Posted by Wotname

………...
Yes, I like the electrical solution ……………..

So far the only suitable electrical sensor that I have been able to locate is this one.
Filter Minder® Heavy Duty Pressure Sensor
While it is not a complete solution as it has no gauge, creating a suitable gauge should not be that difficult. You need to supply the sensor with a 5V supply and then read the output on a voltmeter with a 0 to 5V range.

[GrahamHO]

Originally Posted by Capt Gill

I like your setup. I presently have the standard optional Racor gauge that mounts on top of the filter assy. for my Perkins 4.108M(50hp). Like you,I believe it's important info right after o/press and eng. temp. (either coolant or oil). What's holding me back is that running about three meters of tubing to the c/pit eng. panel introduces the possibility of a vacuum leak (Murphy's Law) defeating the idea if it happens. So, I'm waiting (due to backlog of higher priorities)to locate a electrical sensor/gauge unit and a settable on/off sensor for an idiot light.
For those who say they don't need one because of regular maint., dual filters + be reminded that stuff happens at irregular times and dual filters won't remedy a before filter restriction or give you any helpful diagnostic info.
Please post if anyone knows where to source the above.

All you need to do is have the gauge in your engine room and have a video camera there sending an image of it to a screen in the cockpit as I've seen in super yachts. Or is that not complicated enough.

[HappyMdRSailor]

Originally Posted by Wotname

And if they are so good, what is better. A differential gauge across the filter or an absolute gauge on the output side of the filter? I can see theoretical reasons for both methods but I have no experience with such matters.

Wottie

The diiferential between boats is that I absolute-ley have them on one, and theoretically would like them on another. ..

For the remote gauge inquiries ...Don't know if it would work for a long run... but I used to use gauge isolators (guards) quite a bit back in my youth...
heavy duty gauge guards, diaphragm seals, instrument isolators | pvc cpvc pvdf polypro ptfe

[Roy M]

Wotname, the vacuum switch I used is the Racor, part number RK20163. I will be installing two of the switches on the fly bridge of a Leopard 39 Power Cat, in the coming weeks. These will be attached to the Racor vacuum gauges on the bridge console. In addition, I will be hooking them to alarm LEDs and piezoelectric buzzers, which will be located adjacent to the gauges. The twin Yanmar diesels will have dual filter bodies with A-B switching located in the engine room, in a location that will be quick to access. The switches use 12 volts DC, which I pull from the engine ignition circuit.

Racor 75900FHX10 FHX-DUAL FF/WS,ROTARY VALVE

This boat is leaving for the Caribbean, via Ensenada ship transport, through the Panama Canal, this winter. He does NOT want engine fuel issues to ruin his adventure.

[Wotname]

Originally Posted by Roy M

Wotname, the vacuum switch I used is the Racor, part number RK20163. I will be installing two of the switches on the fly bridge of a Leopard 39 Power Cat, in the coming weeks. These will be attached to the Racor vacuum gauges on the bridge console.........

Are the bridge console mounted vacuum gauges mechanical or electric?

[Wotname]

Originally Posted by HappyMdRSailor

Wottie

The diiferential between boats is that I absolute-ley have them on one, and theoretically would like them on another. ..

For the remote gauge inquiries ...Don't know if it would work for a long run... but I used to use gauge isolators (guards) quite a bit back in my youth...
heavy duty gauge guards, diaphragm seals, instrument isolators | pvc cpvc pvdf polypro ptfe

Hmm...those gauge isloators look interesting. There is a quadzillion MAP sensors in the market place but most (all?) are only suitable with air media. These isolators would allow them to used with diesel media.

Nevertheless the filter minder sensors I referenced earlier look the most promising solution to me (at this stage )

[HappyMdRSailor]

Originally Posted by Wotname

Hmm...those gauge isloators look interesting. There is a quadzillion MAP sensors in the market place but most (all?) are only suitable with air media. These isolators would allow them to used with diesel media.

Nevertheless the filter minder sensors I referenced earlier look the most promising solution to me (at this stage )

Agreed !

Also....

Electrically... There's a bazzilion options... most of 'em prolly under $30-50 for an ebay effort to narrow the final design...

[Roy M]

The Racor gauges are mechanical. I will be using a pretty long run of vacuum hoses for the two gauges at the fly bridge. If that doesn't work out, I'll go to copper tubing, but I'm not expecting any issues.

I'm currently waiting to speak with a Parker/Racor tech to confirm the vacuum hose run. If it doesn't pencil out, we will still be using the vacuum switch to make an electrical alarm circuit to warn us that something nasty is about to happen. I like having the gauge so as to have the most complete and early notification of the filter status, but it's nice to have the pure electric as a second option. I'll get back with the results later, as the West Coast Racor techs don't open until three hours from now.