New Delphi Filter blocks

[ditchcrawler]

An interesting video on a new dual filter/ water separator  block where the diesel can flow past  the filter medium. I wonder if todays engine mariners take this into consideration 

Delphi quality issues - multiple faults in one component!

Delphi quality woes Part 2 - cures and more horrors

Edited October 28 by ditchcrawler
Found the first video

[DHutch]

Saw the same video as I follow Phil's activities on facebook, some what disappointing and alarming state of affairs. 

 

But certainly worth checking if you use such a thing. 

[blackrose]

I think he'll need to change that glass bowl and the plastic drain plugs if he's using it on a boat.

 

I have a single CAV/Delphi sediment/water trap pre-filter on the fuel line from my diesel tank which I fitted nearly 15 years ago, but there's also a fuel filter on the engine.

 

Several years ago while doing a service I couldn't get the element on the CAV/Delphi to seal and a couple of forum members kept insisting I was overtightening it, even though I'd done all my own servicing for many years and never had the issue before. In the end they were proved wrong and the issue was down to poor quality filter elements. Once I changed brand of element it sealed fine.

 

That through port he showed in the video from one side of the unit to the other which allows unfiltered fuel to bypass the filter isn't really a quality control issue, it's a basic design flaw. With my single unit, would that issue still be relevant? I can't figure it out. 

 

Edited October 30 by blackrose

[Tony Brooks]

34 minutes ago, blackrose said:

That through port he showed in the video from one side of the unit to the other which allows unfiltered fuel to bypass the filter isn't really a quality control issue, it's a basic design flaw. With my single unit, would that issue still be relevant? I can't figure it out. 

 

 

Not even a design flaw - a fitting flaw. They are designed to allow fuel flow to be either left to right or right to left, so the inlet and outlet are present on both sides, with arrows cast into the head to show which is inlet and which is outlet. For this to work there has to be a direct connection between the two sides in each case so you get a single entry/exit into/out of the element. 

 

This feature is present on the heads of both CAV agglomerators and sedimentors and always has been.

 

If the fitter or the chap on the vid. ignores the arrows, then what does anyone expect to happen. They have been like that for the 60 odd years, I  have been dealing with them, and the straight through bit is a non-issue if you RTFM and act on it.

[Col_T]

I don’t think it would be an issue with a single filter installation. My understanding of the problem is that, if the fuel filter is blocked (full of crud) then the through drilling would allow fuel, that has passed through the sedimentor, to bypass the filter.

[Tony Brooks]

1 hour ago, Col_T said:

I don’t think it would be an issue with a single filter installation. My understanding of the problem is that, if the fuel filter is blocked (full of crud) then the through drilling would allow fuel, that has passed through the sedimentor, to bypass the filter.

 

I see, but am not sure that is correct because unless the sedimentor outlet is connected to the agglomerate inlet (filter) within the casting, fuel could not get into the agglomerator. If the agglomerator blocked, I don't see how unfiltered fuel could get from the agglomerator inlet port to its outlet port. The only way, as I see it, is if the filter is not sealed to the "nose" on the filter head and that would imply an O ring was left out or was worn. That could be the result of poor manufacturing tolerances though.

[blackrose]

1 hour ago, Tony Brooks said:

Not even a design flaw - a fitting flaw. They are designed to allow fuel flow to be either left to right or right to left, so the inlet and outlet are present on both sides, with arrows cast into the head to show which is inlet and which is outlet. For this to work there has to be a direct connection between the two sides in each case so you get a single entry/exit into/out of the element. 

 

This feature is present on the heads of both CAV agglomerators and sedimentors and always has been.

 

If the fitter or the chap on the vid. ignores the arrows, then what does anyone expect to happen. They have been like that for the 60 odd years, I  have been dealing with them, and the straight through bit is a non-issue if you RTFM and act on it.

 

Ok I see, so the guy in the video was wrong then?

[Tony Brooks]

21 minutes ago, blackrose said:

 

Ok I see, so the guy in the video was wrong then?

 

Without having one in my hand I can't say that, and when I was on the tools they were separate items with a little length of bent pipe between them. I am sure that the single unit agglomerator or sedimentor can only pass fuel direct from inlet to outlet if you ignore the arrowheads, and I can't see how the twin unit would be any different, but can't be sure without having one or the technical drawing for one showing the ports and drillings.

 

However, the outlet from the first unit must connect to the inlet of the second unit and there should be a blanking screw in the other end of that drilling so no unfiltered fuel van get out. If this were not so there would be no way to get fuel into the second unit. Likewise, the outlet port for the first unit should have at blanking screw in it.

[David Mack]

He has the pipe connectors and blanking plugs in the appropriately marked connections. I.e. one in and one out. But it isn't clear how the fuel flow is supposed to work. To me it looks as if the inlet connections (at both ends) lead into the headspace above the filter and agglomerator - the two headspaces on either side seem to be connected by a through drilling. The outlet connections are connected through the long drilling in the 'rib' to the centre boss of both the filter and the agglomerator, which would put the two units in parallel rather than in series!

In the video he has plugged the long drilling on the outlet side. I think this means there can now be no flow through the agglomerator, but at least the filter is no longer bypassed.

[DHutch]

Phil is lots of things, but not ignorant or in competent. 

 

If you watch the video its quiet clear, the ports in the upper casting are wrong for the intended use and place the filters in parallel not series. 

 

Other areas also lack the required concentricity and or squareness to function as required. 

 

Its not for a boat. 

[Iain_S]

Looks like a design fault to me : the double head is obviously developed from the single head, and it appears both inlet and outlet drillings are present on both sides of each single head, although the "inlet" between the heads is on the opposite side of the heads. (not sure how the inlets are arranged on a single head, in line or opposite sides) As the outlet drilling is central, fuel from the first outlet is also in the drilling for the second outlet, and thus bypasses the second filter.

[David Mack]

16 hours ago, DHutch said:

If you watch the video its quiet clear, the ports in the upper casting are wrong for the intended use and place the filters in parallel not series. 

That was my conclusion too. If you Google delphi double filters you will see units for sale with double filters, double aglomerators and one of each. The first two have the filters or aglomerators in parallel in order to provide double the fuel flow rate. Units with one of each are presumably supposed to have the two elements in series, and therefore a different port layout within the head. Looks to me as if the unit in the video has been supplied with the wrong head type.

Edited November 11 by David Mack

[TunnelTiger]

On 28/10/2025 at 10:02, ditchcrawler said:

An interesting video on a new dual filter/ water separator  block where the diesel can flow past  the filter medium. I wonder if todays engine mariners take this into consideration 

Delphi quality issues - multiple faults in one component!

Delphi quality woes Part 2 - cures and more horrors

 

First video - the filter is white with blue printing.  I've never seen these before, only the black and red bands.  It has the old CAV logo, which I don't remember on a CAV 296, and I'm going back 50 years.  I've never noticed "CAV" anywhere on a Delphi 296.  Is the whole unit a fake/knock off?

[blackrose]

On 10/11/2025 at 23:22, DHutch said:

 

Its not for a boat. 

 

As opposed to?

8 hours ago, TunnelTiger said:

 

First video - the filter is white with blue printing.  I've never seen these before, only the black and red bands.  It has the old CAV logo, which I don't remember on a CAV 296, and I'm going back 50 years.  I've never noticed "CAV" anywhere on a Delphi 296.  Is the whole unit a fake/knock off?

 

Could be, but on the other hand they could just be fake/knock off/cheap filter elements. I've had a couple of those with the branding printed upside down that wouldn't seal. 

[TunnelTiger]

11 hours ago, blackrose said:

 

As opposed to?

 

Could be, but on the other hand they could just be fake/knock off/cheap filter elements. I've had a couple of those with the branding printed upside down that wouldn't seal. 

 

It wasn't only the element, there were problems with the filter unit. Poor machining so the bowl didn't fit or seal properly was one. I think the whole unit is a fake.

[blackrose]

26 minutes ago, TunnelTiger said:

 

It wasn't only the element, there were problems with the filter unit. Poor machining so the bowl didn't fit or seal properly was one. I think the whole unit is a fake.

 

Yes I know, I watched the video. My point was that poor quality doesn't necessarily mean the whole unit is fake. You're just guessing as am I.