Time to check

powerskipper

powerskipper

Well-Known Member
Joined
18 Sep 2003
Messages
12,287
Location
Dorset/ Hampshire. south coast
www.facebook.com
those primary fuel filters guy and girls, 2 boats I know off in the Solent area have had muck in them, so just do a quick check before going out, only takes a min.

old container,
pop down engine bay or reach down depending on boat and just undo the nut on the bottom. drain a bit off. if nice pink fluid then your fine, if not drain till it is.

Enjoy your boating.
 
powerskipper said:
those primary fuel filters guy and girls, 2 boats I know off in the Solent area have had muck in them, so just do a quick check before going out, only takes a min.

old container,
pop down engine bay or reach down depending on boat and just undo the nut on the bottom. drain a bit off. if nice pink fluid then your fine, if not drain till it is.

Enjoy your boating.
Click to expand...

If filters are becoming doing their job but gradually becoming choked fuel will still run clear from the dran. If more boats had properly engineered fuel systems with restriction gauges most of this grief could be avoided....All the stuff about clear bowls for visual checks...that yellow with age, all junk. Fiddling about working on a blocked Racor in a seaway is all nonsense. Simple easy to replace spin on filters.

Grurrrr.
 
Last edited:
Better still if you have room fit twin filters with change over taps so if one blocks you can just switch to the other quickly.

Changing a blocked filter on a lee shore.... not good!.

W.
 
Other than a larger flow rate, why did separ decide that 4 x bolts to take a lid off is better than just simply unscrewing a T handle lifting out the filter, pushing another one in then screwing the top back on, it can be done in 30 seconds if the filters are sited in the correct place, which makes me wonder why do some builders place the most important piece of filtering kit in the most stupid of places, one day im going to make a list of boats, models etc and place the 1 to 10 of worst designed engine rooms ever on here, something that you dont read about from MBY much when they do there tests, as no doubt the reports are edited by the supplying boat dealer before print!
 
Just done both of my antedeluvian (just for Latestarter :)) olde Perkins,1 x primery and two secondary filters per engine.All in,using pattern filters, about £25.00,so no excuses about cost.
The 3 hours spend in Karma Sutra awkward positions,the fact that no matter how many sets of gloves/overalls etc you wear,you still reek of diesel for days afterwards and the wife refuses to wash the stuff in her machine,so you have to do it when she is out.......beyond price.
 
One for volvopaul - have you found a way to swap filters in a 4 bolt Separ without having to bleed the engine after. I dislike the Separs I have so much I think I'm going to swap them for Racors.
 
powerskipper said:
those primary fuel filters guy and girls, 2 boats I know off in the Solent area have had muck in them, so just do a quick check before going out, only takes a min.

old container,
pop down engine bay or reach down depending on boat and just undo the nut on the bottom. drain a bit off. if nice pink fluid then your fine, if not drain till it is.

Enjoy your boating.
Click to expand...

Powerskipper, be careful. A primary filter does 2 things: it filters out crud and it separates out water. Draining the bowl till you get red fuel is merely draining out the water that has been separated, nothing else. It tells you nothing about how clogged the fliter is.

The only way to measure the extent to which the filter is clogged (apart from inspecting it and seeing the black slime of diesel bug!) is to measure the pressure differential each side of the filter. That's what the restriction gauge in Latestarter's post does. I have these gauges fitted to all my hydraulic (bow/stern thruster system and stabilisers) filters, including green-amber-red on the dial as well as bars of pressure differential, but alas the mainstream separ/racor fuel filters that manufacturers fit to production boats dont have these pressure differential guages, which is a shame. They would be cheap as chips to install too - I bet they would add merely £10 to the cost of a filter unit. Ho hum. Better still would be if racor/separ made filter sets with nmea2k interfaced restriction monitors, so you could get early warning of filter problems on your Garmin screens. Maybe someone will make such a product soon.

Till then, you just have to change the filters fairly often based on spec sheets, because there is no way of knowing if the filter is 50% blocked or 20% blocked or whatever, and therefore there is no way of knowing how much useful life a filter has left before it will cause engine performance problem. And ideally have twin filters with instant changeover valves for when you get an unexpected load of dirty fuel. But please don't think the filter is ok just because clean pink diesel comes out of the bottom drain plug
 
Thanks

jfm said:
Powerskipper, be careful. A primary filter does 2 things: it filters out crud and it separates out water. Draining the bowl till you get red fuel is merely draining out the water that has been separated, nothing else. It tells you nothing about how clogged the fliter is.

The only way to measure the extent to which the filter is clogged (apart from inspecting it and seeing the black slime of diesel bug!) is to measure the pressure differential each side of the filter. That's what the restriction gauge in Latestarter's post does. I have these gauges fitted to all my hydraulic (bow/stern thruster system and stabilisers) filters, including green-amber-red on the dial as well as bars of pressure differential, but alas the mainstream separ/racor fuel filters that manufacturers fit to production boats dont have these pressure differential guages, which is a shame. They would be cheap as chips to install too - I bet they would add merely £10 to the cost of a filter unit. Ho hum. Better still would be if racor/separ made filter sets with nmea2k interfaced restriction monitors, so you could get early warning of filter problems on your Garmin screens. Maybe someone will make such a product soon.

Till then, you just have to change the filters fairly often based on spec sheets, because there is no way of knowing if the filter is 50% blocked or 20% blocked or whatever, and therefore there is no way of knowing how much useful life a filter has left before it will cause engine performance problem. And ideally have twin filters with instant changeover valves for when you get an unexpected load of dirty fuel. But please don't think the filter is ok just because clean pink diesel comes out of the bottom drain plug
Click to expand...

Thanks I love these type of threads as you learn something new all the time. I use it as a gauge that further inspection may be required.

What you said makes a load of sense , its just a shame it is not thought of by the makers.
 
jfm said:
P
I have these gauges fitted to all my hydraulic (bow/stern thruster system and stabilisers) filters, including green-amber-red on the dial as well as bars of pressure differential, but alas the mainstream separ/racor fuel filters that manufacturers fit to production boats dont have these pressure differential guages, which is a shame. They would be cheap as chips to install too - I bet they would add merely £10 to the cost of a filter unit. Ho hum. Better still would be if racor/separ made filter sets with nmea2k interfaced restriction monitors, so you could get early warning of filter problems on your Garmin screens. Maybe someone will make such a product soon./QUOTE]

I hope there are some prodct planners looking in here!

Just spent this morning rigging an engine for dyno test tomorrow. I was handling the damm things less than an hour ago. My pressure sensors are industrial grade, extemely accurate with 1/8 NPT male fitting and lead out to dyno control interface, made in a whole range of outputs. I no longer use mechanical gauges unless I really have to. Let me see what voltages are available and at what cost. On the face of it outputting J1939 signal should be a no brainer!
Click to expand...
 
Latestarter1 said:
Just spent this morning rigging an engine for dyno test tomorrow. I was handling the damm things less than an hour ago. My pressure sensors are industrial grade, extemely accurate with 1/8 NPT male fitting and lead out to dyno control interface, made in a whole range of outputs. I no longer use mechanical gauges unless I really have to. Let me see what voltages are available and at what cost. On the face of it outputting J1939 signal should be a no brainer!
Click to expand...

Sounds good! 24v or 12v would be useable. If you can output a j1939 signal from them, then I can buy off the shelf j1939-n2k converter (little black box) from maretron, which gets the signal onto my N2k network. I already have the software/interface to write a "label" to translate the n2k signal so that it will display on my dash as "port engine primary fuel filter differential too high" or whatever. Or display an actual value for the pressure differential

Your 1/8 NPT pressure trnasducers would output only the absolute pressure. I'd need a bit of software to compute pressure differential between two of them, and output the answer to that substraction in N2k or j1939 format. That part needs some specialist skills

FWIW here is pic of my main hydraulic pack (early in the build so it is missing some hoses) in relation to which the spec was "everything top quality and oversize; no corners cut". Low pressure oil filter is the black box to right, and back, of cuboid oil tank, above the line of the sight guage on the tank wall. You can see a simple pressure differential guage on the front of it (round white 50mm guage, quite bright in the pic, and it has red/green/amber markings plus bars on the face of the gauge). There is another gauge on the high pressure filter, not in this pic. Come the think of it, the grey plastic vertical cylinder to the right is a filter for the watermaker and even that has a gauge. Which proves these things are pretty straightforward. It's only the sodding Racor/Separs filters that don't have them! Grrrr.

P1010457.jpg
 
Last edited:
Another thumbs down for the 4 bolt Separ. Ours was that close to the underside of the cabin sole that is was almost impossible to remove the filter. Fiddly beyond comprehension and something I would not have liked to attempt at sea.

Solution was to change for a Racor
 
powerskipper said:
those primary fuel filters guy and girls, 2 boats I know off in the Solent area have had muck in them, so just do a quick check before going out, only takes a min.

old container,
pop down engine bay or reach down depending on boat and just undo the nut on the bottom. drain a bit off. if nice pink fluid then your fine, if not drain till it is.

Enjoy your boating.
Click to expand...

One of my jobs this last weekend, but I usually shut off the fuel supply taps on each tank so it cant siphon then drop the drain screw out of the bottom of the primary filter so all the contents flushes out fast into a contanier, bringing with it all the crud if there is any. Pop the drain screw back in and lift the filter out to see if there is any sign of clogging. turn the taps on and bleed thro to the engine. Easy ...... well it would be if I didnt have to dismantle part of the heating to get my bulk close to the starboard filter. Why dont boat builders make regular maintenance items more accessible. Moan.
 
Wiggo said:
Is this the one?
http://www.asap-supplies.com/search/RAC-RK11-1676E/racor-vacuum-gauge-51mm-030hg

And so I'm clear, it just replaces the T handle, nothing else needed? That looks like a cheap solution for peace of mind...
Click to expand...


not quite

you replace the t handle with one with that screwed into the top of it.

Basically the t handle has a hole through the centre and the gauge mounted on the top.

alternatively, mount on a t piece on the pipe between the filter and lift pump.
 
Last edited:
kashurst said:
One for volvopaul - have you found a way to swap filters in a 4 bolt Separ without having to bleed the engine after. I dislike the Separs I have so much I think I'm going to swap them for Racors.
Click to expand...

Yes its very easy,

Before you do anything, close the valve from the tank, place drain tin under drain bung, open tap watch what comes out, probably nothing if its blocked.

Undo 4 bolts, take out filter, if its bad get an old brush but not a paint brush as the bristles fall off and end up in the bowl, small washing up brush with plastic bristles are good, clean out the debis, pour some diesel from your 5 litre can that you should keep in the engine room(thats how you dont have to bleed the system after), close the drain plug after your happy its now clean in the bowl, fill nearly to top, fit new filter, fill close to top, refit top, turn on tank valve, if your tanks are full it may syphon through when you open the bleed valve on the top of the filter housing, if it does you know 100% there is no air in the system.

As a rule on a service I will strip down the whole assembly, fit new rubber seals etc, then its pristine for the season.

Screw on filters are also easy with your can of diesel in the engineroom, just unscrew theold one, fill the new one and screw it on, no bleeding req.
 
volvopaul said:
Yes its very easy,

Before you do anything, close the valve from the tank, place drain tin under drain bung, open tap watch what comes out, probably nothing if its blocked.

Undo 4 bolts, take out filter, if its bad get an old brush but not a paint brush as the bristles fall off and end up in the bowl, small washing up brush with plastic bristles are good, clean out the debis, pour some diesel from your 5 litre can that you should keep in the engine room(thats how you dont have to bleed the system after), close the drain plug after your happy its now clean in the bowl, fill nearly to top, fit new filter, fill close to top, refit top, turn on tank valve, if your tanks are full it may syphon through when you open the bleed valve on the top of the filter housing, if it does you know 100% there is no air in the system.

As a rule on a service I will strip down the whole assembly, fit new rubber seals etc, then its pristine for the season.

Screw on filters are also easy with your can of diesel in the engineroom, just unscrew theold one, fill the new one and screw it on, no bleeding req.
Click to expand...

When you say "keep in the engine room" I presume you mean for the duration of the service only? Definitely not allowed to keep any conbustable fluids including engine oil in the engine bay of a coded boat. A pain because I've excellent storage for all these things in my engine bay.
 
jfm said:
Better still would be if racor/separ made filter sets with nmea2k interfaced restriction monitors, so you could get early warning of filter problems on your Garmin screens. Maybe someone will make such a product soon.
Click to expand...

Maretron have been selling N2K fluid pressure and Vacuum sensors for some time now.
 
david_bagshaw said:
not quite

you replace the t handle with one with that screwed into the top of it.

Basically the t handle has a hole through the centre and the gauge mounted on the top.

alternatively, mount on a t piece on the pipe between the filter and lift pump.
Click to expand...

I bought one of these vacuum guages.
I removed the T handle and replaced it with the guage. Whilst it fits it isn't right. It doesn't form a good seal. The T handle has a seal. The guage doesn't. If you take the seal off the T handle and put it on the guage is doesn't work as there is no flat part on the guage for the seal to push against. Quite disappointing and lacking any design consideration. As David has suggested you need the 'special' T handle to mount it on but why? Where do you get one of these special handles?
Had it been designed so that it formed a seal it would be ok. As it is I wouldn't recommend one.
 
You must log in or register to reply here.

Share this page

Top