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RobBrown
10-04-14, 15:41
Anyone know if the Delphi 296 & 901 filters are interchangeable? Was supplied one of each. They look the same size. Usually use 296s, but will keep the 901 if compatible.

Daydream believer
10-04-14, 17:30
I have had trouble with the CAV filter every year since I got the boat.
Stopping it leaking has been a real pain
I checked the diameter of the rebate in the bottom of the filter & on 4 different makes there was 1.8 mm difference in diameter
the largest diameter is better for leak prevention
however, i bet there are loads of leaking CAV filters on boats all over the place. they are Carp

Hadenough
10-04-14, 19:48
L
I have had trouble with the CAV filter every year since I got the boat.
Stopping it leaking has been a real pain
I checked the diameter of the rebate in the bottom of the filter & on 4 different makes there was 1.8 mm difference in diameter
the largest diameter is better for leak prevention
however, i bet there are loads of leaking CAV filters on boats all over the place. they are Carp

Don't start me off! I've just spent the whole day bleeding the bleeding fuel system. Bought some budget filters which just don't fit (lesson there). Replaced the primary with a "proper" filter and hey presto. Having said that I've never had a problem in the past but the CAV filter assembly is so basic that how do they think you will get a seal anyway! Glass bowl type (not in the engine bay) but the bloody filter comes with a seal short! Got another CAV to do on the genset tomorrow. Definitely be fitting Racor screwins next winter.

pvb
10-04-14, 20:34
The CAV filter is essentially simple and easy, but you do have to realise that there are 2 different sizes for the big O-rings.

superheat6k
10-04-14, 20:39
L

Don't start me off! I've just spent the whole day bleeding the bleeding fuel system. Bought some budget filters which just don't fit (lesson there). Replaced the primary with a "proper" filter and hey presto. Having said that I've never had a problem in the past but the CAV filter assembly is so basic that how do they think you will get a seal anyway! Glass bowl type (not in the engine bay) but the bloody filter comes with a seal short! Got another CAV to do on the genset tomorrow. Definitely be fitting Racor screwins next winter.
+1 for the Racor, but there is a very good Headman copy of the Racor available on EBAY for half the price and as good quality IMHO, and will take original Racor elements, although I use and have extensively tested the headman own elements and filters for my business.

http://www.ebay.co.uk/itm/Racor-type-500-FG-diesel-filter-water-separator-/380710908427?pt=UK_CarsParts_Vehicles_BoatEquipmen t_Accessories_SM&hash=item58a423720b

This is the 500 size, but they also offer the 900 size. I have had two of the 900 fitted for two seasons and they work as well as the Racor and do not leak.

KenMcCulloch
10-04-14, 20:50
The CAV filter is essentially simple and easy, but you do have to realise that there are 2 different sizes for the big O-rings.

Quite so. I've never had a problem with a CAV filter, well only once.

Hadenough
10-04-14, 20:58
Yes I do realise that! But tell me why, without going into whether or not you should have a glass bowl, even up market filters only come with two, not three, replacement O rings! The problem with CAV filters is that they are so crude. Five seals, wobbly, at best construction. (Push the two tier assembly up into the top seal and furtle around trying to find the thread of the female thread!) And the bleed screw relies on a taper seal only, too many things to go wrong. Incidentally, after taking the callipers to the cheap filters against the better one the problem seems to be in the inner "tube" which doesn't have enough of a lip to make the seal. Effectively, as it it is tightened it pushes the lip of the tube off the o ring. The tube of the better filter goes right through the filter.

wully1
10-04-14, 21:02
Do the Racor type filters work with the small flow rates of a 20 to 30 HP engine?

superheat6k
10-04-14, 21:11
The Racor has two functions, so the spinner action may be less at low flow rates, but the element is still effective, and acts as an agglomerator as well as a filter, and you could use a lower micron rate, say 10 instead of 30 micron for lower service flow rates.

Racor do offer smaller units similar in appearance to the CAV, but no experience of them. Plenty on EBAY.

RobBrown
10-04-14, 21:15
Well I put in a CAV as a 1ry filter replacement for an agglomerator & to me it has proved a cost effective replacement and a great improvement on the original fitting. bought the unit plus filter from SLs and was les than 20 and direct swap on the exisiting fitting bolts, whereas with Racor set up, I wa slooking @ 100+. I replaced the filter in mine last week for the first time & to be honest dd not find it a particualr trial. In fact the 2 filters were ordered as replacement spares for the 296 cartridge replaced (2 each). Now tried the inlinefilters site suggested. Couldn't find any simple cross reference facility, but after searching for the type of filter & turning up Baldwin filter FBW-BF825, in the list of compatibles for are included both the Delphi 296 & HDF 901, so by inference, they should be interchangeable. Bit round the houses, but makes some sense!

The 296 btw only has 2 large seals, top & bottom & the small seal on the tube, but thats all thats required on my glass bottom CAV filter unit.. I found them pretty simple to replace.

ghostlymoron
10-04-14, 22:07
Can't understand how such a simple and widely used unit can cause a problem if properly installed. Thousands of farmers and digger drivers do it every day.
I have had trouble with the CAV filter every year since I got the boat.
Stopping it leaking has been a real pain
I checked the diameter of the rebate in the bottom of the filter & on 4 different makes there was 1.8 mm difference in diameter
the largest diameter is better for leak prevention
however, i bet there are loads of leaking CAV filters on boats all over the place. they are Carp

savageseadog
10-04-14, 22:16
The only thing that's wrong with CAV filters is the ham fisted amateurs that fit them

Daydream believer
11-04-14, 04:19
The only thing that's wrong with CAV filters is the ham fisted amateurs that fit them

Thanks- that has solved that problem then.

macd
11-04-14, 15:41
A CAV tucked away in an awkward location: no thanks, I'd go with a spin-on every time.
A CAV you can freely get at?: no worries, simple, cheap, cheap filters (and the ones with a priming pump on top are a boon).

RichardS
11-04-14, 15:46
The Racor has two functions, so the spinner action may be less at low flow rates .....


I don't think my Racor 500 spinners actually spin on either of my 3YM30s with 10 micron filters. Is that normally the case with 30HP engines?

Richard

ghostlymoron
11-04-14, 16:35
If it's in an awkward place, move it.
A CAV tucked away in an awkward location: no thanks, I'd go with a spin-on every time.
A CAV you can freely get at?: no worries, simple, cheap, cheap filters (and the ones with a priming pump on top are a boon).

Hadenough
11-04-14, 16:37
The only thing that's wrong with CAV filters is the ham fisted amateurs that fit them

Totally agree, Anyone else would fit a quality filter :encouragement: As for changing the element my post was a warning about using cheap after market elements. When I retried with good quality elements I got a seal straight away.

Daydream believer
11-04-14, 17:01
A CAV tucked away in an awkward location: no thanks, I'd go with a spin-on every time.
A CAV you can freely get at?: no worries, simple, cheap, cheap filters (and the ones with a priming pump on top are a boon).

My CAV is fitted on a mounting with butterfly nuts. It is dead easy to remove & the fuel line is long enough for me to place the assembly over a bucket.
I have even removed it & assembled it on a bench with no luck.

& as for earlier posts- I have stripped& rebuilt dozens of Diesel engines in my earlier days- I used to look after the plant in a building company. So " ham fisted amateur" does not really fit the bill.

alan17
11-04-14, 20:36
I would not call other people "ham fisted" but certainly some people are less adept at doing certain jobs.

My set up uses a CAV filter and I am reasonable adept at changing filters without leaving a leak. When I buy new elements they are supplied with 2 large seals of slightly different sizes and a much smaller seal. The problem is that I need 3 of the large type seal. I contacted Crosland, the manufacturer of the element that I use and told them that I needed extra of one of the large seals. They simply asked how many extra I would like and sent them to be at no cost.

To be fair to the anti CAV brigade I would not relish the thought of having to fit a new element in a choppy sea! I have arranged a by pass system using 2 CAV filters and some on/off taps to reduce the possible need to change at sea. It has so far not been necessary but that may be inviting a problem!

Hadenough
11-04-14, 21:03
I would not call other people "ham fisted" but certainly some people are less adept at doing certain jobs.

My set up uses a CAV filter and I am reasonable adept at changing filters without leaving a leak. When I buy new elements they are supplied with 2 large seals of slightly different sizes and a much smaller seal. The problem is that I need 3 of the large type seal. I contacted Crosland, the manufacturer of the element that I use and told them that I needed extra of one of the large seals. They simply asked how many extra I would like and sent them to be at no cost.

To be fair to the anti CAV brigade I would not relish the thought of having to fit a new element in a choppy sea! I have arranged a by pass system using 2 CAV filters and some on/off taps to reduce the possible need to change at sea. It has so far not been necessary but that may be inviting a problem!

Absolutely! Why on earth they don't provide the three seals required as a matter of course is beyond me. I totally agree with the problem of changing it at sea, it's not too difficult with the right components but it is fiddly (even though I'm not a ham fisted amateur). Bleeding is not the problem if you are set up properly it is the time necessary to fit the bloody filter element. Not being a weekend warrior, I'm going to fit spin on filters.

causeway
12-04-14, 22:23
Absolutely! Why on earth they don't provide the three seals required as a matter of course is beyond me. I totally agree with the problem of changing it at sea, it's not too difficult with the right components but it is fiddly (even though I'm not a ham fisted amateur). Bleeding is not the problem if you are set up properly it is the time necessary to fit the bloody filter element. Not being a weekend warrior, I'm going to fit spin on filters.


Only problem I've had is bleeding the dam thing. Ended up using an oil pumper outer, sorted it in seconds. I'm going to carry some large bore syringes for the job next time.

Daydream believer
13-04-14, 07:08
Only problem I've had is bleeding the dam thing. Ended up using an oil pumper outer, sorted it in seconds. I'm going to carry some large bore syringes for the job next time.

I fitted a bellows pump in the fuel line ( rated for diesel) makes it dead easy to bleed as it blows the fuel through both filters immediately & no need to use the engine lift pump

slipknot
13-04-14, 07:12
I fitted a bellows pump in the fuel line ( rated for diesel) makes it dead easy to bleed as it blows the fuel through both filters immediately & no need to use the engine lift pump

+1. Easy peasy.

alan17
13-04-14, 08:22
What I should add to my earlier post is that I have on/off taps in the pipelines either side of the CAV filters and the filters are located below the fuel level in the tank. Therefore I can isolate the filters from the supply, change the filters and then open the tap that will allow fuel into the filters, open the bleed screws, close the screws when fuel comes out at the bleed point, open the tap allowing fuel to flow to the engine. Job done

Kelpie
13-04-14, 12:03
I fitted a bellows pump in the fuel line ( rated for diesel) makes it dead easy to bleed as it blows the fuel through both filters immediately & no need to use the engine lift pump

Is that similar to a bulb primer, or is it something else?

slipknot
13-04-14, 13:21
Is that similar to a bulb primer, or is it something else?

Yes, its a bulb primer like you would find on an outboard motor fuel line. Except spec'd for diesel use. I bought mine off eBay. Makes filter changes, and bleeding afterwards, a very easy job.

brianhumber
13-04-14, 17:18
+1. Easy peasy.

+2

Simply do not understand why people are having troubles

The CAV 296 would not have been been sold and fitted to 100,000 of engine installations worldwide over many decades if it was difficult to change. I have had to change ones fitted in accessible locations and in accessible locations needing a mirror to see to get the parts aligned correctly for assembly since I first went to sea in the early 70s. Apart from cleanliness and a modicum of care in reassembly, the only point to note is that rubber ring between body and glass can squeeze out if the clamping bolt has been overtightened.

Only last week responded to a panic wail from someone that an engine filter was dripping diesel when running and he had to re-bleed the engine to start it. The bolt had been overtightened by at least 5 turns so the poor little O ring on the bolthead was shredded, the glass bowl rim chipped by the excessive clamping pressure and the rubber ring between the element body and glass bowl squeezed out at the back. 2 for a new filter element and 9 new glass bowl with new sealing rings, 5 minutes fitting time and engine was running again leak free.

Brian

Daydream believer
13-04-14, 18:36
the only point to note is that rubber ring between body and glass can squeeze out if the clamping bolt has been overtightened.



Brian

Made worse by the fact that all the filters i have tried all seem too small- delphi, New Holland, Perkins etc- & one only has to put the slightest pressure on for it to distort
& yes!!! - I am putting the correct ring on

RivalRedwing
13-04-14, 19:12
If you want a cheap alternative then you can get a CAV 496 which is a spin-on head and filter. Used by Land Rover and the like, far cheaper than Racor... Whole assembly costs 16, filters 6

WoodyP
13-04-14, 21:02
I got shouted down on a previous thread for being happy with a CAV. Cheap and cheerful, not complicated but had to change to an alloy bowl because the insurers inspection didn't like a glass bowl.

RivalRedwing
14-04-14, 16:15
Made worse by the fact that all the filters i have tried all seem too small- delphi, New Holland, Perkins etc- & one only has to put the slightest pressure on for it to distort
& yes!!! - I am putting the correct ring on
Delphi shouldn't be - they are the OE manufacturer (= Lucas' new name)

scottie
14-04-14, 16:35
Absolutely! Why on earth they don't provide the three seals required as a matter of course is beyond me. I totally agree with the problem of changing it at sea, it's not too difficult with the right components but it is fiddly (even though I'm not a ham fisted amateur). Bleeding is not the problem if you are set up properly it is the time necessary to fit the bloody filter element. Not being a weekend warrior, I'm going to fit spin on filters.

Most likely because the glass bowl is not the most common of set ups

Daydream believer
14-04-14, 18:14
Most likely because the glass bowl is not the most common of set ups

Trouble is that one would want to see if there is water collecting without having to drain fluid off to check
but now you have mentioned it i will try the original metal bowl for size comparison