D
DogWatch
Guest
Ok, I am wrong and have thus far it seems just been lucky.
I have spare elements on board, I will add them to the list.
I have spare elements on board, I will add them to the list.
Debunking myths... Fuel filters, do you really need to change them?
davidej
Well-Known Member
I fully admit to not being an expert so shoot me down if you like.
I don't see how filter would (or should) remove those. It is intended to remove solid particales above a certain size. The sulphur is part of the hydrocarbon molecules and the fame/glycerin/ water are liquids.
Not that I am saying we shouldnt replace them but I am sure that for us buying diesel in N European marinas and having clean tanks, do it much more frequently than really necessary.
LadyInBed
Well-Known Member
Twin switchable filters is the way I would like to go.
Where in the system is the vacuum gauge, I can't quite envisage the setup.
I used to have a vacuum gauge on the inlet manifold of a Mini Cooper!
penfold
Well-Known Member
Modern cartridge filters are capable of coalescing distributed liquid contaminants, and the better ones will tell you how good they are at removing them.
AntarcticPilot
Well-Known Member
There seems to be an assumption that what is removed by a filter is necessarily going to be visible. One poster mentioned that the filter will remove quite a bit of water - which would not be visible, in a black and gungy sense. Furthermore, in a marine environment I'd expect a major contaminant to be salt - again, white and not readily visible on a filter.
So, I change mine annually to be sure. Rather that that find that my engine won't work when I need it - that has happened once to me, which is precisely once too often for me!
So, I change mine annually to be sure. Rather that that find that my engine won't work when I need it - that has happened once to me, which is precisely once too often for me!
Bobobolinsky
Well-Known Member
Got no problems with racor, or even some of the generics, that are a little cheaper. Racors have the ability to fit water sensors, which not many have. They are the best way to prevent water and bugs getting to the engine. Still run an agglomerator and final filter. What is wrong with CAV filters other than having lots of little O rings that can be displaced. Physically, they are only boxes. The filters inside have been continually upgraded and are not the same product as 50 years ago. The agglomerator is there to turn sub micron varnishes and contaminents into particles that can be filtered out. Varnish can ruin pumps and make valves sticky. Hunting diesels, can burn pistons.
pvb
Well-Known Member
Vacuum gauge is simply connected to a T-joint in the pipe between the primary filter and the engine. Mine's a Racor gauge.
Last edited:
D
Deleted member 36384
Guest
pvb I have the dual filter arrangement from Vetus which has the Vacuum gauge mounted directly on the manifold. Your arrangement is obviously remote from the filters which is a good idea. Is the vacuum gauge pipe sealed or is it filled with air, diesel on the remote set up?
By the way, the top right screw on the middle panel is out of alignment.
By the way, the top right screw on the middle panel is out of alignment.
blueglass
Well-Known Member
Depending on your set up of course, but certainly on my own secondary filters, it is necessary to dismantle the housing, and purge air from the system afterwards, so the work involved in inspection is the same as replacement, and as they are pretty cheap items it seems daft to reassemble using the old ones even if they "look" alright.
davidej
Well-Known Member
Including FAME??? It is put there to be burnt as fuel not to be filtered out.
And I would have thought the glycerin was in solution not suspension. I find his calculations very suspect!
KellysEye
Well-Known Member
A general comment about fuel filters I change ours when they look dirty. I've always found Racor filters difficult to take off, I often have to knock a screwdriver through it. On the premise that takes quite a long time and if you were on a lee shore unable to sail off with a blocked filter... So I changed the two inline filters to parallel with appropriate switches. Just as motorboats have.
vyv_cox
Well-Known Member
I'm not recommending this to anybody. I owned my old diesel VW camper for 20 years, during which time it covered about 150,000 miles. I never even knew it had a fuel filter until the last year before I sold it. Never changed it once.
silverdawn
Well-Known Member
fuel filters
Hi,all I change my filters once a year, 20hp beta engine not many miles under power about 300nm last season tank always kept topped up to avoid condensation problems and water drained from prefilter every 6months (not very much water comes out) main fuel tank is a vectus plastic tank and looks clean ie no crud floating about, i also change the oil filters yearly.
I was speaking to a berthholder near me regarding servicing , he has a 33ft motor sailer and does many more motoring miles than me, since he has owned the boat (4years) he has never changed any filters ! so is he just lucky or possible proof the majority of us could in fact change our filters less, myself I will be sticking to my schedule,I think he is pushing his luck to far and could through his bad maintenence have engine failure which could put him and others in danger.anyway no conclusive answer, you have to do what suits you and when your out there on your own and the engine keeps plodding away you like to think its because you seviced it and not just down to luck.
Hi,all I change my filters once a year, 20hp beta engine not many miles under power about 300nm last season tank always kept topped up to avoid condensation problems and water drained from prefilter every 6months (not very much water comes out) main fuel tank is a vectus plastic tank and looks clean ie no crud floating about, i also change the oil filters yearly.
I was speaking to a berthholder near me regarding servicing , he has a 33ft motor sailer and does many more motoring miles than me, since he has owned the boat (4years) he has never changed any filters ! so is he just lucky or possible proof the majority of us could in fact change our filters less, myself I will be sticking to my schedule,I think he is pushing his luck to far and could through his bad maintenence have engine failure which could put him and others in danger.anyway no conclusive answer, you have to do what suits you and when your out there on your own and the engine keeps plodding away you like to think its because you seviced it and not just down to luck.
pvb
Well-Known Member
Vacuum gauge is connected with a fairly rigid nylon tube, which has air in it.
By the way, the top right screw on the middle panel is out of alignment.
I'm mortified! Is it too late to put in a warranty claim to Hallberg Rassy, I wonder?
LadyInBed
Well-Known Member
I take it that as the flow reduces, the vacuum indication also reduces?
pvb
Well-Known Member
There doesn't seem to be much change in the vacuum reading. Remember that diesel engines generally pull much more fuel than they need through the filter, and return some to the tank.
However, as the filter starts to get clogged with gunge, the reading does rise. Latestarter mentioned that "fuel systems can tolerate about 10" of mercury (Hg) restriction before starving for fuel", and you'll see that the Racor gauge's red sector starts at 10"Hg.
Latestarter1
Well-Known Member
Those of you who have been to sea will understand what I mean when say that CAV filters were designed when fuel injection ppumps had internal tolerances akin to "kicking a sausage down the working alleyway". The CAV paper element are inexpensive because in this world you only get what you pay for. CAV filters have no Beta ratio qualification forget what they say regarding microns, and no coalescing qualities, they will pass any amount of emusified junk to the last chance filter which will likely clog. Only one place for them is the scrap bin.
Fuel injection systems have changed dramatically over the years, however numpties who install new engines are still in a time warp and think of CAV as OK and misguidedly think of Racor turbine as the bees knees. A Racor is just about OK as part of properly designed multi stage system.
Modern simple to maintain and inexpensive cartridge filters with a coalescing media are the answer.
NUTMEG
Well-Known Member
Thank you. I ask because I was about to buy another, second, filter for my 1GM10. it has the 'on the engine' filter plus a sediment/water trap.
I need to buy a body + filter, so what would you suggest?
Any advice most appreciated.
Steve
I need to buy a body + filter, so what would you suggest?
Any advice most appreciated.
Steve
pappaecho
Well-Known Member
Picked up Pepsi (new old boat) in August with new changed primary and secondary filters. Motored from Plymouth to Portland Bill when engine stopped. Go into Portland, primary filter completely clogged, diesel colour of dilute black sump oil. Motored on to the Needles, when engine stopped again. Got to Yarmouth roads, took up buoy, changed primary filter again, apparently against the clock as crew timed the exercise.. 17 minutes to tie up, change filter, bleed system, start engine and cast off.
Diesel tank very badly contaminated with diesel bug and rust.
Conclusion. CAV filters do work. Filters are there to stop damage to the injector pump. Perhaps primary filter should be twinned, with appropriate tappage for either/or use so you can change filter on the fly ( like the Lifeboats do)
Diesel tank very badly contaminated with diesel bug and rust.
Conclusion. CAV filters do work. Filters are there to stop damage to the injector pump. Perhaps primary filter should be twinned, with appropriate tappage for either/or use so you can change filter on the fly ( like the Lifeboats do)
NUTMEG
Well-Known Member
Not annexpert
Spent twenty years as an agricultural mechanic and must have changed hundreds of CAV type filters, mainly on MF tractors. Can not say if they were good or not, but some of those tractors were 40+ years old and many are still seen on local farms. My 1GM10 is a pretty agricultural looking lump!
Spent twenty years as an agricultural mechanic and must have changed hundreds of CAV type filters, mainly on MF tractors. Can not say if they were good or not, but some of those tractors were 40+ years old and many are still seen on local farms. My 1GM10 is a pretty agricultural looking lump!