Fuel filters

[nebulae]

Decided to sort out fuel filters properly before we have any more problems . Got a bit confused about separators/agglomerators and fuel filters,not helped by blank faces at local motor factors .I now think I have got it clear .With the common Lucas/CAV filter cases,the following seems to be correct .Separators have a short metal case between top and bottom covers.Inside is a metal cone.No relaceable parts.This is first in the system.Just needs draining or cleaning occasionaly.As fitted to early Landrover Discoverys. .Agglomerator is next .This has a replaceable filter.The only agglomerator filter I can find is a Dephi 296.This is NOT the same as the standard filter,The difference is obvious(holes in the top of the filter).Many agglomerators have a clear plastic or glass bottom bowl.These are not acceptable for boats,There is a version with a metal bowl .Then comes the fuel filter with a 5 micron filter(As fitted to Landrovers,tractors etc)Plastis drain bungs,as fitted as standard to all filter cases are not acceptable.Midland Chandlers sell proper metal replacement drain bungs .Much confusion about this subject.paticularly as all these units look very similar.Apparently,there are three ways of measuring the effectiveness of fuel filters,and this information is very difficult to obtain.Generaly,a 5 micron filter will filter 50% of 5micron impurities.Hope this information is of use,No doubt if I am in error in any way,other members of the forum with a better understanding will post a correction.Note- many Dephi 296 are advertised on line as fuel filters.This is correct,but is not the full picture.I dont know the micron rating of this unit.

[nebulae]

Just to add to the above,the full part number of the agglomerator is HDF 296.This is a Dephi number(who now own the lucas CAV brand.)

[luggsy]

Have a look at this http://www.fuel-guard.co.uk/index.php/agents-distributors/

[Tony Brooks]

All fuel filters will agglomerate. The CAV 296 element you describe is known as a pocket filter but may third party filters are the traditional pleated type. However they all agglomerate but pocket filters have a longer life, take any water to exit the filter at the bottom while the flue turns back on itself to flow upwards. In pleated filters the fuel and water exit horizontally and only turn through 90 degrees. I prefer the pocket filters as do many diesel car & truck OEM filter suppliers (if you cut the can open to see). Mann & Hummel supply pocket filters the same as the 296.and some other makers do as well but not I think the Purolator/Fram/Coopers group.

 

Modern CAV sedimentors seem to have just a filter top with a plastic cone pushed onto it and a fairly deep bowl.

[nebulae]

Thanks for your reply Tony .At the moment we have 2 Massey tractors in the yard .They both have twin filter housings of the old style Lucas CAV type .This is neat,but both tractors have two Coopers filters .Cant quite see the point if they are ordinary fuel filters.Probably should have had one of the pocket filters and one pleated?.Fitted by a Massey agent,which proves how much confusion is about .I have rigged up two separate filter cases in line to fit to the boat .Might see if I can locate one of these double units as it makes a neat instalation .Not sure whether to bother with a separator .There is a third filter in line .It is the one fitted to the engine by Isuzu .Left it last in line as only genuine filters seem to fit the housing and filters are £15 EACH.

[Timleech]

Thanks for your reply Tony .At the moment we have 2 Massey tractors in the yard .They both have twin filter housings of the old style Lucas CAV type .This is neat,but both tractors have two Coopers filters .Cant quite see the point if they are ordinary fuel filters.Probably should have had one of the pocket filters and one pleated?.Fitted by a Massey agent,which proves how much confusion is about .I have rigged up two separate filter cases in line to fit to the boat .Might see if I can locate one of these double units as it makes a neat instalation .Not sure whether to bother with a separator .There is a third filter in line .It is the one fitted to the engine by Isuzu .Left it last in line as only genuine filters seem to fit the housing and filters are £15 EACH.

 

A lot of the CAV-style twin filters have the filters in parallel, for extra capacity, not in series, so both ought to have the same element.

 

Tim

[KarlosMacronius]

Just to add that glass/plastic bowls ARE OK for boats IF they exhibit the correct CE mark (i.e they are heat resistant to a temperature considered high enough by the BSS).