Good recommendation for first fuel filter - Diesel Engine (Isuzu 35)

[canalboat77]

We have been having a lot of issues with our first (tank) fuel filter and filter housing sucking in air, and it's time for a change. We currently use the attached. Anyone recommend one they like to use? 

 

Thanks in advance for your help and advice.

 

 

 

[Tracy D'arth]

No reason why it should allow air in if it is assembled correctly. Its a bog standard 296 type filter and there are millions of then in use. 

[BEngo]

The Delphi 296 is a popular filter and housing. Lots on the web, some cheap Chinese copies which are warped and leak air like yours.  Buy a decent one and you will be OK.  It will also be an easy replacement for your present one.  Check the inlet and outlet  threads are the same on the new one as the existing one. Check also that it has a metal drain screw if you need to pass BSS. Screws are available from MC, or there should be one in your current filter.

Replacement heads are also available from ASAP, which would be cheaper than a whole unit,  if the threads match.

 

Otherwise Vetus sell some good but extremely overpriced filter units.  If going this route find out the generic filter part number before buying as they will be a lot cheaper.

 

Finally, an ACD 60 or 600 are good units.  Much fitted to elderly Listers.

N

 

Edited December 18, 2022 by BEngo
Add ASAP

[ditchcrawler]

I fitted one in the engine room at gunwale height and that was OK for a few hundred hours and then would suck air. The diesel tank is behind the weed hatch. I moved the filter to the stern on the swim and had no more problems. I put it down to a vacuum forming due to flow resistance as the filter aged and the length of run, plus lift from the tank.   Maybe a 1/2" pipe from the tank to filter would have fixed it.

Edited December 18, 2022 by ditchcrawler
Add photo

[Tony Brooks]

1 hour ago, canalboat77 said:

We have been having a lot of issues with our first (tank) fuel filter and filter housing sucking in air, and it's time for a change. We currently use the attached. Anyone recommend one they like to use? 

 

Thanks in advance for your help and advice.

 

 

 

 

I would lay odds it is misfitted, twisted, or the wrong seal in the wrong place OF the center bolt sealing.  As said probably millions in use all over the world and have been for over 60 years.

 

A but about the center bolt. The housing comes, or did come, in two types. One sealed by a small O ring on the bolt. This type has the top of the bolt hole tapered and just to complicate matters some filters have been supplied with an undersized O ring that leaks.

 

I think earlier versions used a soft washer under the bolt head, usually copper but I have seen nylon or fiber. The body hole is parallel all the way down with a machined face around the hole.

 

Using the wrong sealing method is likely to cause ongoing problems.

 

Assuming this is the primary filter and there is another between lift pump and injector pump I would suggest that you change the body and base for the cast aluminum parts to form a sedimentor that will not block as readily as the filter you show, yet will remove 80% of any water and the larger dirt particles. The engine filter will deal with the residue.

 

[blackrose]

I also use Delphi 296 filters or equivalents with a CAV/Delphi water separator/sediment pre-filter. 

 

A few years ago I had an issue with a leaking filter and although a couple of forum members kept insisting I'd fitted the element incorrectly, that turned out not to be the case at all. I can't remember the brand of filter I used but there's a thread in the archives somewhere. 

 

I'd conducted this filter change several times before without any issues so there was no reason I'd done it incorrectly and the filter element supplier also admitted to me that they'd had quality problems with a batch of that particular brand. When I later changed the filter to a different brand it didn't leak.

 

So my advice is: after re-checking how you've fitted the filter, that all o-rings are properly in place and that you haven't overtightened the unit, don't necessarily believe those who insist that you've done it wrong just because there are thousands of these filters in use and it's never happened to them! 😏

Edited December 18, 2022 by blackrose

[Tony Brooks]

Personally  would always try to get filters branded CAV, Mann & Hummel, or Baldwin. That filter shoudl have a pocket filter element, all to many second line makes seem to use pleated filters, and that includes those that were once very well known and respected.

[Alan de Enfield]

 

It is very easy to forget to remove the original o-ring up inside the filter housing, and, when you put the new one in you have two o-rings and will not get a good seal.

[ditchcrawler]

50 minutes ago, Tony Brooks said:

Personally  would always try to get filters branded CAV, Mann & Hummel, or Baldwin. That filter shoudl have a pocket filter element, all to many second line makes seem to use pleated filters, and that includes those that were once very well known and respected.

Here is a photo I posted some time ago. I only use Delph

 

[reg]

I had constant problems with my original CAV filter unit on a barrus shire 40.

Tried everything recommended but still sucked in air. Eventually replaced it with a new one about 12 years ago and never had a problem again, for  £36.60 (assuming it's a Delphi) it's worth a punt.

May just be a minor invisible fault with the unit.

Edited December 18, 2022 by reg
Make clear it was the CAV unit not the filter

[Dav and Pen]

The OP s filter Fleetguard is the Cummins brand so should be good quality Always found cav and mann good

 

Edited December 18, 2022 by Dav and Pen
Spelling

[Tony Brooks]

Addition to my last post.

 

Delphi (what Brian uses) is what CAV morphed into so Delphi also fine.

[dmr]

Maybe buy a new fillter head to take the 496 filter. There are a bit like the 296 but use a deeper screw on filter. This only has one easy seal (ok, maybe 2) that are built in so you don't have to fiddle with. Much easier to replace if access is not good, or if you have to do an urgent change.

 

I am in a minority of one (or maybe 2) in that I suspect that in some circumstances its possible to "suck" the disolved air out of the fuel which looks like an air leak but isn't. This could happen if your tank is floor mounted so below the level of the engine?

[BD3Bill]

It is possible that it is something other than the filter sucking in air.

That would be your return/spill line possibly, which won’t necessarily leave a pool of fuel for you to see. 

You have had some excellent advice and I am firmly in the Delphi camp fwiw. 

 

[ditchcrawler]

2 hours ago, dmr said:

 I am in a minority of one (or maybe 2) in that I suspect that in some circumstances its possible to "suck" the disolved air out of the fuel which looks like an air leak but isn't. This could happen if your tank is floor mounted so below the level of the engine?

See my post, it could have been what I was getting but didn't consider that and suspected it was drawing passed the seals

[dmr]

11 minutes ago, ditchcrawler said:

See my post, it could have been what I was getting but didn't consider that and suspected it was drawing passed the seals

I am 100% sure that my fuel system is not sucking air after the fuel cock, I just might have a pinhole inside the tank in the fuel pickup pipe, but otherwise I must be sucking air out of the fuel.

Ive made a return from the top of the second filter to remove any air which has "solved" the problem.

[Tony Brooks]

15 minutes ago, dmr said:

Ive made a return from the top of the second filter to remove any air which has "solved" the problem.

 

One way or another I would expect an Isuzu to already have that or a similar feature, maybe bleeding from the injector pump inlet back to the tank. Bit maybe not having individual injector pumps. If there is no such provision the a bleed back from the filter is a good idea.

Edited December 18, 2022 by Tony Brooks

[Tony Brooks]

Just been looking at images. The 35 I found does have a leak off "self bleeding" return cunning along the the top of the injector pumps via banjos. I can't see why that would not quickly purge any air from the system.