cav filters

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silverdawn

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Hi all, my existing primary filter is a lucas F7111 HDS 296 which I removed recently, just as well because it was full with
thick black gunge surprised the engine kept going.
However when I ordered a replacement I given a Mahle KX23
filter which the supplier assured me was the replacement for the Lucas Ive been on the Mahle web Site but cannot find any info, have any of you knowledge of these filters, it appears good quality and is a well known brand but I would like to be certain before fitting.
The engine had a service 2006 but it seems they overlooked the primary filter , unless it has taken only 2
seasons to gunge up.
 
Thick black gunge sounds like Diesel Bug.

Quote
"Microbial Growth (diesel bug)
Diesel bug is a 'catch all' term for the many single cell creatures and plants that either grow on the walls on the tank, at
the interface between water or in the sludge at the bottom of the tank. These bugs tend to clump together to form mats,
which accumulate in / on filter surfaces which then block the filter. When you remove a filter that has been block by diesel
bug you will find a mat of slime-like growth. If you have a water separtor, you might find a black frog spawn type slime in
there or a mat of stringy type slime. These are the common type of diesel bug growths but you could have others types."
 
I suggest you investigate cleaning the gunge out of your tank while you can. A primary filter can easily block completely if the fuel is stirred up a bit in a seaway. Your engine will then not run.

I once helped deliver a boat that had been sailed for years in sheltered waters. Our route took us on a much more lively course and the engine stopped. We opened the filter to find it completely blocked with thick, black gunge. The replacement filter blocked within five minutes and was in just the same condition. Eventually we put in four or five new filters before we were able to continue.

Best way is to remove the tank and steam it out, but there are many alternatives if this is not convenient. Sucking the stuff out with an oil drain pump works well.
 
I guess the Mahle will fit but I would be more circumspect about it being the same. I had a long chat with a CAV tester some time ago (Rochester City Diesels in Medway) and he knows his stuff. He will only sell the original heavy duty (HD) 296 filters - pattern ones are often cheaper because 1) they have less filter material in them or 2) the filter material is of a poorer quality - it is possible to investigate 1) by eye but there is not much the average yottie can do to test 2). If the fine crud gets through then over time (probably years) your pump and injector suffer increased wear. LSUK outlets will sell the genine article as will (as I recall) asap supplies.
 
There are a lot of alternative filters available which fit these.
I personally buy 5 at a time at approx £1 each from a local motor fcator shop. I then chnage the filter at least twice a year.
I notice that others have said the quality may vary with price, but my way of looking at this is that it is a also a main filter and what you are trying to do is filter out 95% of teh nasties before teh main filter and to avoid the need to chnage teh main filter more than once every two years or so. I would rather pay £1 each change twice a year and keep 5 as spaares.

Regads
 
I bought one of these from Volvo Penta agent while buying other VP items. Needless to say it cost £9.25 but no other supplier nearby.

Are marine filters any different to CAV vehicle filters?
 
[ QUOTE ]
I bought one of these from Volvo Penta agent while buying other VP items. Needless to say it cost £9.25 but no other supplier nearby.

[/ QUOTE ]

Sounds like the Volvo bug - more typically £4 +/- £1
 
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