Primary fuel filter - there has to be a better way

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davidej

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We have recently acquired a Bene361 with a VP2030. It has a primary fuel filter, which is a top ally casting with the hoses, vents etc, then a can filter and a glass bowl at the bottom to collect crud, water etc. The fuel tank is plastic and as the fuel in the bowl always looked as clear as a bell we haven't tried to change it before.

Having emptied it and reassembled with a new can filter, we tried to refill it. It is mounted several inches above the motor mounted filter and about a foot above fuel level in the tank.

The lift pump didnt seem to do the job. We checked that it wasn't 'on the cam' but it seemed to make no difference. Can one really expect it to lift fuel a foot or so if it is pumping air?

In the end we took out the bolt holding it together (carefully supporting the bowl) and filled it with the use of a small funnel - no mean feat given the confined space.

There must be a better way! Any suggestions? You certainly couldn't do it that way at sea!
 
davidej said:
Having emptied it and reassembled with a new can filter, we tried to refill it. It is mounted several inches above the motor mounted filter and about a foot above fuel level in the tank.

There must be a better way! Any suggestions? You certainly couldn't do it that way at sea!
Click to expand...

On many boats these are in the line to the lift pump and above the fuel level in the tank. This makes priming difficult especially with the undersized lift pumps on modern engines.

One way the process can be helped is to lightly pressurise the fuel tank. I find just blowing into with some hose just sealed with some rag at the filler is OK though I have a small v ent hose. For those short of breath then a dinghy pump will do the trick.
 
I have the same problem. It's on my list to move the filter below the fuel level. Bear in mind though that if you move the filter unit to the engine compartment you should theoretically avoid the glass bowl version in case of fire. If the glass breaks in the heat it will syphon the tank into the flames!

I do the same as you. Prime the filter with the jug from the galley. Horrible job.
 
Is The Pump Being Stroked Fully?

On my boat the priming pump appears not to be working despite good lever movement. Its only when the last 1/4" of quite stiff lever movement occurs does the pump lift. It is quite powerful once the knack is found. It takes ages to fill the glass on the filter and a cramped finger to boot. Maybe you are not stroking the pump fully. However, on this boat we have big fuel tanks and the head of pressure in the tanks will push the fuel along the line with a little effort from the pump.

On another boat I used to fill the bowl and offer it up full. Messy. Never thought about blowing fuel through though.

A fitted a new twin filter housing from Vetus last year. Now very east to switch filters on the fly. If you are changing one you should consider the dual unit. All manifolded and valved ready for pipes.
 
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You should find a bleed screw on top of the housing. Take the screw out and us an oil sucker on the hole. Or use pressurisation of the tank as already suggested, a dinghy pump works well.
 
It is possible to buy a replacement Lucas/CAV type primary fuel filter/water separator with a priming pump built in to the top. This is used to fill the bowl/filter quickly and then you use the lift pump on the engine to bleed the remainder of the system. Try ASAP Supplies (www.asap-supplies.com) and search for CAV filter.
 
grievesie said:
It is possible to buy a replacement Lucas/CAV type primary fuel filter/water separator with a priming pump built in to the top. This is used to fill the bowl/filter quickly and then you use the lift pump on the engine to bleed the remainder of the system. Try ASAP Supplies (www.asap-supplies.com) and search for CAV filter.
Click to expand...

Second!!
Spent a bl***y after lunch trying to prime a Yanmar 4JH4E; had to disconnect hose at the entrance of the injection pump and suck.

Mind You, some mistakes I made:
A) did't close the valve at the exit of the reservoir,
B) having changed the fuel filter, I wasn't at first careful enough in mounting and re-setting the two rubber seal (top and lower) which are DIFFERENT.
 
Same problem on my boat where the filter is at about the same level as the top of the fuel tank. Simple solution is to buy a rubber squeezy pump of the sort used on outboard fuel tanks. Prime it with a little diesel and fit it on the outlet side of the filter with a short tube. Pump until the filter is full and a little runs out into a container. Job done, no mess, costs about a tenner.
 
davidej said:
We have recently acquired a Bene361 with a VP2030. It has a primary fuel filter, which is a top ally casting with the hoses, vents etc, then a can filter and a glass bowl at the bottom to collect crud, water etc. The fuel tank is plastic and as the fuel in the bowl always looked as clear as a bell we haven't tried to change it before.

Having emptied it and reassembled with a new can filter, we tried to refill it. It is mounted several inches above the motor mounted filter and about a foot above fuel level in the tank.

The lift pump didnt seem to do the job. We checked that it wasn't 'on the cam' but it seemed to make no difference. Can one really expect it to lift fuel a foot or so if it is pumping air?

In the end we took out the bolt holding it together (carefully supporting the bowl) and filled it with the use of a small funnel - no mean feat given the confined space.

There must be a better way! Any suggestions? You certainly couldn't do it that way at sea!
Click to expand...
On my Bene 351 it had the same system, the lift pump was the same CR AP!! The thought of trying to bleed it in a rough rolly sea filled me with horror!
I did the same as Sailing Holidays, I went to a scrappy, found an old Peugeot diesel and blagged the squeezy bulb primer, I then cut the rubber tube near to the secondary filter intake and fitted the bulb there. BINGO, priming every time in a couple of secs. No probs in 4 years and no prob leaving it in the system.
Stu
 
Been there got the 'T' shirt (or Diesel all over me) to prove it.

Two points,
Re-filling the bowl:
Buy a 'rubber bulb' with 600mm of hose attached the type used on small outboard motors fuel pipes for priming, and just connect it to the 'outlet' of the filter and it will suck it through no problem and then just get rid of last bit of air with the lift pump, nine times out of ten the engine will start anyhow.
Second point:
Technicaly you should have the filter below the level of the tank so it is gravity fed, you solve one problem then give yourself another probably due to access,BUT it will help the fuel pump much better.
Hope this might help

Mike
Archivist for the Colvic Watson Owners Group
 
I don't suffer this particular problem because my filter is below tank level but, rather than try to use the little lever on the fuel pump, I bleed my engine by turning the engine over using the starter. Is this not a simpler way of doing it? Or am I likely to do any damage?
 
alahol2 said:
I don't suffer this particular problem because my filter is below tank level but, rather than try to use the little lever on the fuel pump, I bleed my engine by turning the engine over using the starter. Is this not a simpler way of doing it? Or am I likely to do any damage?
Click to expand...

Depends on how much You need to bleed: might badly discharge the engine battery!
 
alahol2
The thing to remember when cranking the engine is you're also pumping cooling water into it. It can back up into the cylinders this way. If you're not intending to start it best to close the intake valve.
 
So long as you have fuel in the lines you can crank the engine to bleed the system. But remember that the fuel lubricates the injector pump, so if it doesn't work fairly quickly then stop! A friend recently mistakenly filled his diesel car with petrol and kept trying to start it. Although the local garage drained the tank and got it going again, it doesn't run quite as well as it used to...

I'm lucky that my filter is below the half full level of my tank, so I undo the bleed on the filter and it fills itself. An extended warm up fills the lines, but look out for high points in fuel lines holding a bubble of air.

Rob.
 
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Caer Urfa said:
Technicaly you should have the filter below the level of the tank so it is gravity fed, you solve one problem then give yourself another probably due to access,BUT it will help the fuel pump much better.
Click to expand...

Unfortunately this is sometimes a problem to achieve when the tank is fitted low down.
 
Fuel Filter

Finbar said:
Same problem on my boat where the filter is at about the same level as the top of the fuel tank. Simple solution is to buy a rubber squeezy pump of the sort used on outboard fuel tanks. Prime it with a little diesel and fit it on the outlet side of the filter with a short tube. Pump until the filter is full and a little runs out into a container. Job done, no mess, costs about a tenner.
Click to expand...

Yes I have done the same on my boat. Made servicing the engine very easy this year.
 
.
Many people comp;ain about the manual lift pump lever not working very well, the primary problem is that the lift pump itself is part way still on the cam, this means no matter how many times you operate the lever you are only getting a short lift.

You need to feel the stiffness in the lever, or more to the point at what stage dose the lever stiffen, the moor free travel, the less fuel.

Try just jogging the engine over a very small amount on the starter and feel the lift pump, when you a nice long high resistance stroke on the lever the pump is off the cam and you get a lot more fuel per pump.

Hope this helps someone.

Avagoodweekend......:)

.
 
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Tom
 
I've always turned the engine (BMC 1.5 - Thornycroft T90) over for a short while (20 secs max). I then find that the lift pump invariably does its job. Once you have the knack bleeding takes no more than a couple of minutes.
 
Fuel Filters & Pumps

Hi All,
A few points: Yes, bleeding the filter(s) by turning the engine over is rough on the high pressure injection pump--so is running out of fuel. Most new ones on smaller engines are fuel lubricated, so no fuel, no lube.

Usually, if you just CAN'T get the darn thing to fill, you do have the pump on the cam, OR, you didn't get all the fiddely seals setted so it's leaking a tiny bit of air.

The CAV filters are a b**** to change and seal in a seaway, and then trying to bleed the system while pitching about in there with a hot engine is just a treat you'll only want once.

Which brings me to my solution: 2 CAVs, 1st one has a bypass so if I start to feel that old stutter that signals a clogged filter, I just bypass the 1st and keep on going. After the 2 CAVs I installed an electric (12v, from the auto shop) fuel pump that I use to bleed the whole system whenever I need to open the system. Okay, I couldn't be satisfied with well enough, so I also ran a T valve off past the electric pump with the other leg going back to the tank via the engine return line. So now I can flip on the electric pump and return valve and run all my fuel thru the first 2 filters in a few hours (also works as a transfer pump between my two 500L tanks.)

As you may surmise, all this followed one of those experiences you only want once. Hope you all install a system like this so that you'll never need it.
 
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