Fuel filter/water separator choice

MikeBz

MikeBz

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I want to fit a fuel filter/water separator with transparent bowl in an easy-to-view location, upstream of the existing primary & secondary filters (which are hard to drain to check for water without spilling diesel). There is a bewildering array of products, especially from Racor. Prices vary a lot too - why would one not choose this CAV Type Fuel Filter and Water Separator (Transparent Bowl) at £43.57 over this Racor 215R10 Diesel Spin-On Fuel Filter at £179.26?

Is there a flaw in my plan? Engine is Perkins Prima M50.
 
MikeBz said:
I want to fit a fuel filter/water separator with transparent bowl in an easy-to-view location, upstream of the existing primary & secondary filters (which are hard to drain to check for water without spilling diesel). There is a bewildering array of products, especially from Racor. Prices vary a lot too - why would one not choose this CAV Type Fuel Filter and Water Separator (Transparent Bowl) at £43.57 over this Racor 215R10 Diesel Spin-On Fuel Filter at £179.26?

Is there a flaw in my plan? Engine is Perkins Prima M50.
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The cheaper one is the well known but fairly crude CAV filter, which is assembled using a central bolt. Two of my boats have had them and they are common on tractors etc. The replacement filters are very cheap. They are perfectly adequate, but the main downside is that changing a filter can be a fiddly business. I once managed to put mine together wrongly and the resulting air leak led to engine failure on final approach to a pontoon. Could have been much worse.
The spin on Racor filter has supposedly got better performance, and it's idiot proof to change the filter, but both the unit and the replacement filters cost more.

So it's up to you... if you're on a tight budget and you can put the CAV in a space where access is good, then it's probably fine. If you're going to be changing filters at arms' length is the back of a locker, the ease of use of the Racor might make more sense.
 
I’m replacing the hopeless CAV setup I have on my boat, I’ve gone big with a Racor 500fg which was expensive, but I note there’s been a significant price increase, 20%, since I bought mine last November.

Racor 500FG Diesel Fuel Filter (10 Micron)

I’ve a sailing boat but nonetheless want the easiest and best possible setup for fuel filtration, I dread having to change the CAV filter whilst at sea, a fiddly filter mounted by the boat manufacturer in a very poor location. There would be diesel spilled within the galley area leading to slippery cabin sole and stinky diesel aroma - guaranteed instant sea sickness.
 
I changed my original primary CAV filter to the screw-on version, identical size with either unf or metric threads(depending on age). Doesn't have the visible clear bowl but this has never been a problem. Can be changed quickly at sea very easily.
 
The main purpose is to have a water separator that I can see into, there are already 2 filters downstream. Points taken about ease/difficulty of changing filters - obviously very important as this will be the first filter that the fuel passes through.

Does the filter have to be lower than take-off on the tank, or lower than the fuel pump?
 
MikeBz said:
The main purpose is to have a water separator that I can see into, there are already 2 filters downstream. Points taken about ease/difficulty of changing filters - obviously very important as this will be the first filter that the fuel passes through.

Does the filter have to be lower than take-off on the tank, or lower than the fuel pump?
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Ideally, you want it to be the lowest point in the whole system, for easier priming. But there are ways around that, e.g. with an inline priming bulb.
 
Don't fit a CAV type. Terrible design, changing the filter is like playing jenga.

Imagine attempting that at sea!! 🤢🤢🤢🤢🤢
Racor copies from ebay are the way to go.

The drop in type need almost 500mm of vertical space.

The copies of screw on type with water seperator are more or less the same size as CAV but quick and easy to change.

CAV are fine on a tractor, but even then, why not fit an easy to change filter.

I don't see that spin on or drop in filters are anymore expensive than CAV types. Not significantly so anyway.

I would put off filter changes when I had Cav. It always took some fettling to get them to seal and sit just right". A royal nuisance and potentially dangerous if you need to do a filter change in a hurry. With drop in or screw on types its a 2minute easy job. A no brainer for me.
 
alahol2 said:
If price is important then check out ebay for the Racor look alikes. They are perfectly good and a fraction of the price.
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Yes. I just fitted one from these people:

Pardon our interruption...

I think you can buy cheaper but this supplier was quick and very helpful with a query I had. Excellent, it just worked first time with no leaks.
I have a megga expensive German, Separ filter on hand which I could have used but very happy with the new one...


1743925759640.png

If anyone needs a Separ 2000, it's available for 50 quid delivered UK.


.
 
Another big (n) for CAV filters.

On my last boat, one of the best things I did was to go to a car breaker and get a pair of matching spin-on filters. A bit of tube and some taps from ASAP and I had two filters in parallel that I could switch in seconds. Of course, after that, I never had any problems with them, and they dropped off my service item list, only getting changed when they got rusty enough to be a concern - maybe every 7-8 years.
 
CAV filters are now Delphi
I had trouble for several years with the one on my new Hanse until my cousin pointed out that I might have a clone.
I changed to the genuine article & have had no trouble since.
The filter is mounted on the side of a panel that is awkward to get to as it is also on my left hand. So I have mounted it on 2 studs with butterfly nuts & long fuel hoses. Now I just remove it & hold it over a bucket. They are dead easy to replace & as my cousin ( Who worked on a farm) says - he has had to change them whilst knee deep in mud & water & done it many times. They are used world wide in all sorts of conditions.
I change mine at the end of each season when laying up & run the engine for a couple of minutes to check all is Ok. I do not leave it until clogged. They are cheap enough from a tractor firm. Then at the start I know I only have to press the key & go.
 
GEM43 said:
I’m replacing the hopeless CAV setup I have on my boat, I’ve gone big with a Racor 500fg which was expensive, but I note there’s been a significant price increase, 20%, since I bought mine last November.

Racor 500FG Diesel Fuel Filter (10 Micron)

I’ve a sailing boat but nonetheless want the easiest and best possible setup for fuel filtration, I dread having to change the CAV filter whilst at sea, a fiddly filter mounted by the boat manufacturer in a very poor location. There would be diesel spilled within the galley area leading to slippery cabin sole and stinky diesel aroma - guaranteed instant sea sickness.
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These are the gold standard - and soooooooooo much better for changing filters than CAV
 
dunedin said:
These are the gold standard - and soooooooooo much better for changing filters than CAV
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Get the cheap knock offs. As cheap as £17.50 on ebay for the filter assembly.

Filters also can be cheap. Its a primary filter/seperator so still protection from your engine mounted filter.
 
The gold standard is the double Racor 500, with the vacuum gauge, and which you can switch on the fly.

It's expensive, and the Chinese knock-offs might be good enough. Or might not be.

I keep a 2 micron filter in one side of my Racor, and a 10 micron in the other. I use the 2 micron every day -- which is as fine as the standard Yanmar secondary, which means that as long as the Racor is clear, nothing is accumulating in the secondary.

If you see the vacuum going up, then you switch over to the other one, without shutting down the engine, and replace the clogging 2 micron filter.

In 15 years with this boat, I've never needed to do that. But having had fuel problems in two other boats, I'm paranoid about it.
 
Dockhead said:
The gold standard is the double Racor 500, with the vacuum gauge, and which you can switch on the fly.

It's expensive, and the Chinese knock-offs might be good enough. Or might not be.

I keep a 2 micron filter in one side of my Racor, and a 10 micron in the other. I use the 2 micron every day -- which is as fine as the standard Yanmar secondary, which means that as long as the Racor is clear, nothing is accumulating in the secondary.

If you see the vacuum going up, then you switch over to the other one, without shutting down the engine, and replace the clogging 2 micron filter.

In 15 years with this boat, I've never needed to do that. But having had fuel problems in two other boats, I'm paranoid about it.
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That sounds like an excellent setup.
 
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