CAV fuel filter

[syfuga]

Two threads on this already, but they don't answer my question. I was too busy mopping up spilt diesel to note how it came apart:

Replacement filters come with two larger rubber gaskets, slightly different in size, and a smaller one.

Vyv Cox maintains that the larger one goes between the glass bowl and the base, whereas I find the smaller one is a better fit.

The larger one seems to fit inside the rim on the top of the filter unit.

The very small one goes on the central spigot, under the top.

Question therefore, is what goes between the top of the glass bowl and the filter cartridge?

At the moment I have put it together with a gasket between the bowl and filter cartridge, as well as one at the top, and one at the base. That seems to be common sense, but I am not sure where the third gasket came from!

Can anyone confirm before I fill it with diesel and spill it everywhere!

 

[pvb]

Replacement filter elements are usually only supplied with 2 large rubber seals, and you're quite right that a third one is required if a glass bowl water separator is fitted. Some chandleries sell the extra seals separately. Many people just re-use an old seal.

 

[Ricd]

RYA Diesel engine video I have clearly says large seal goes into the top of the CAV unit and the small one is the lower one between bowl and filter

 

[Slipperman]

Just changed mine - you may have a different arrangement to me, but my glass bowl just sits on a metal plate into which the central shaft screws, hence no need for a bottom seal. So, as you suggest, the two main seals provided go up into the top housing and between the new filter element and the glass bowl.

 

[pvb]

Just changed mine - you may have a different arrangement to me, but my glass bowl just sits on a metal plate into which the central shaft screws, hence no need for a bottom seal. So, as you suggest, the two main seals provided go up into the top housing and between the new filter element and the glass bowl.

Oh, no! There must be a seal between the bottom of the glass bowl and the bottom plate of the filter.

 

[syfuga]

Filter mystery

Thanks everyone.

I deduce they supply the top and the one between bowl and filter and assume the bottom one is ok.

So I have four pieces, 3 gaskets between, and the small one on the central spindle. It should be fuel tight!

I am ashamed to admit that the last time I changed the filter was in 2004, and had not even noticed the sh20 in the bowl..

Emptied the tank out today, and agreeably surprised to find no water and minimal slime after using fuel additive..

 

[omega2]

Two supplied, three required, big one goes up into filter head, small one goes base of bowl to filter bottom, the one you need goes between the bowl and the filter. TIP use one of the previously used ones, and in future keep saving instead of exchanging, also spin the assembly up the screw, it lines up better. The tiny one slips onto the set screw. On dissasembly have a plastic bag handy ease the screw then spin off catching the lot in the bag, an old bucket is then good to place the lot in to clean up the base, save the rubbers and carry away the the rubbish.

 

[alan17]

CAV filter

You do need an additional sealing ring. Although you only get 2 with some makes where there is a glass bowlyou need 3. No problem (usually) with reusing one of the old rings butif you contact CAV they will send you FOC some additional seals.

Alan

 

[pvb]

There's also another seal, an O-ring about 15mm diameter, which goes on the spigot which the filter fits on to.

 

[Roberto]

There's also another seal, an O-ring about 15mm diameter, which goes on the spigot which the filter fits on to.

yep, all the cartridges I bought had four o-rings: two large ones (one slightly smaller than the other), a middle size one like 15mm dia that goes around the internal spigot, and the very tiny one like 4-5mm for the central bolt, to be fitted near the head.

 

[Spyro]

You do need an additional sealing ring. Although you only get 2 with some makes where there is a glass bowlyou need 3. No problem (usually) with reusing one of the old rings butif you contact CAV they will send you FOC some additional seals.

Alan

I'm finding it difficult to find a website for Lucas CAV. Anyone got an address?

 

[oldvarnish]

Two supplied, three required, big one goes up into filter head, small one goes base of bowl to filter bottom, the one you need goes between the bowl and the filter. TIP use one of the previously used ones, and in future keep saving instead of exchanging, also spin the assembly up the screw, it lines up better. The tiny one slips onto the set screw. On dissasembly have a plastic bag handy ease the screw then spin off catching the lot in the bag, an old bucket is then good to place the lot in to clean up the base, save the rubbers and carry away the the rubbish.

Or..... fit Racor filters as I have done and you can do this holding a cup of tea in one hand, whilst wearing your best suit. Well, almost. They're much easier and cleaner to work with than CAV filters. The filter element itself even comes with a neat little carrying handle so you don't get your fingers too filthy. And you don't have to bleed, at least I don't seem to need to.

 

[Jabamusic]

Hi
Recently did a filter change and am now spending more time peering in to see if it is leaking (which so far it isn't) than doing any of the other things that need to be done at this time of the year!!
I have so little confidence in the set up. Note it is me that has the low confidence level..I know that these have been around for years etc, but I also know I will attend to filters etc much more readily and often with a better arrangement.

Therefore.........what can I replace the standard CAV-type filter/glass bowl setup with? Racor has been mentioned - but costly. Are there any less expensive alternatives?

Jaba

 

[Stemar]

This thread reminds me why I sacked my CAV filter.

Imagine trying to sort that lot out on a lee shore in a gale and an 8 foot swell, which is when filters tend to bung up

I now have two spin-on filters in parallel, with 4 taps ( could have used 2 Y taps, but 4 simple ones and a bit of pipe was a LOT cheaper. Filter holders from a car breaker and taps & pipe from ASAP.

If a filter blocks, I turn off the duff one and turn on the the spare. It takes seconds. Changing the blocked one doesn't take much longer. Easy-peasy, even in a chop.

Yes, the filters cost a tenner instead of three quid, but I'm quids in because I don't regard changing them as a maintenance item. If the motor seems to be struggling, I'll switch filters and see if it makes a difference (5 years without a change and counting)

Annual maintenance consists of turning all the taps through 90 deg and back so they don't seize.

 

[Poignard]

I gave up on the messy CAV and fitted a Racor. Well worth the expense, in my opinion.

 

[exfinnsailor]

Dump the whole lot in a jiffy bag works wonders. Remove all the bits fit new seals and reassemble with new seals. Mine had Volvo written all over it and the new filter came with all the rings. Don't over tighten the bolt and change all the rings. If your thinking of going near a lee shore in a gale don't use marina diesel. Get it from ASDA its far cleaner and less chance of the bug but I am sure someone will be along in a minute with a different opinion

 

[LittleSister]

So which makes of filter come with the complete set of seals for a the glass bowl version?

Are there various versions of the Lucas CAV (and consequently different filter models in each brand) or just one? (I currently have a Crossland 522 filter fitted.)

 

[PetiteFleur]

So which makes of filter come with the complete set of seals for a the glass bowl version?

Are there various versions of the Lucas CAV (and consequently different filter models in each brand) or just one? (I currently have a Crossland 522 filter fitted.)

Just bought mine today, FRAM C 1191 PL and comes with 5 seals. They seem fine and I try and change the seals everytime but do have to dig out the one in the body with a sharp pointed thing. Soon after I got the boat had great difficulty in getting a leak free seal, had to remove the filter completely and discovered TWO seals in the body! Once removed, groove cleaned out and new seal fitted had no problem with getting a good seal. One day when feeling flush I may get a Racor spin on type.......

 

[Roberto]

So which makes of filter come with the complete set of seals for a the glass bowl version?

Are there various versions of the Lucas CAV (and consequently different filter models in each brand) or just one? (I currently have a Crossland 522 filter fitted.)

If you search "CAV" in the Asap supplies site for example

http://www.asap-supplies.com/search/cav

you get a few different models,
first difference: 296 cartridges (short) and 796 cartridges (taller),
second difference, the bowl, four types: alloy square-ish, alloy round-ish, plastic/glass squareish, plastic/glass rounded

I can speak for a 296 cartridge filter fitted with a round bowl (similar to the fourth filter, top row of the first page of asap site, but fitted with a short cartridge): I could find cartridges almost everywhere, sometimes they are sold in cardboard boxes and some orings are lost, you buy two and you have all four of them
Otherwise, Fleetguard parts FF167A (agglomerator, it has slits on the underside) or FF167 (normal filter) come in a sealed plastic bag, the four orings being inside the bag.


If you have the Crossland 522 it should be the short one, the other equivalent being: Crosland 358, Crosland 522, Crosland 522NG, Crosland 533, Crosland 544, Crosland 566

(if you want the whole list of all equivalent from different make let me know)

 

[SHUG]

Calm down everybody.
The non-messy way to change a CAV filter is to use a plastic fridge bag. Slip it over the filter assembly before you start and then the filter and the normally spilt fuel all ends up in the bag and not in the bilges........ Simples!!!