Diesel and air leaks! Blasted beggaring ball breaking barsteward!

[Cardo]

Well, I've done as much as I can for now, and I can't detect any further leaks. However, what I've discovered is that after running the engine for a while, air bubbles appear at the bottom of the filter element in the CAV filter. As soon as the engine is switched off, the bubbles disappear back up into the filter element. I think these are what are causing me concern. It would seem air is trapped in the filter and won't come out during normal bleeding procedures. The design of the filter seems to allow air to become trapped in the element with no easy way to get it out, aside from this slowly seeping out as the engine runs and movement eeks it out.

I've resorted to bleeding the filter after each trip in order to get the small bits of air that do move up to the filter outlet, where the bleed screw is.

Any thoughts on this?

 

[KellysEye]

I would change to Racor filters they have a bleed pump on top, that's why we had them. You are not the first to have problems with CAV filters.

 

[rob2]

I'd second the advice to use soft copper olives as the brass ones are too hard for use on copper pipes and often don't deform evenly onto the pipe. I understand why you want to use flexible hoses - much easier to route around the engine bay - but bear in mind that an engine fire would now have access to all the fuel in the tank, especially as you say it flows by gravity feed! The Boat Safety Scheme isn't a requirement for sea-ging vessels, only inland waterways licensed ones, but they do demonstrate best practice for installation. They suggest solid, fireproof pipes for all the rigid installation with a flexible hose allowed only to bridge from the bulkhead to the engine. In addition there should be easy access to a fuel cut-off valve prior to the flexible hose without opening the engine box and leaning over the fire! They also suggest that either an extinguisher system should be fitted inside the engine room or an closable access hole provided to shoot a handheld one through (must get round to doing that on mine!).

Rob.

P.S. Can't remember your giving any details of the return system. I don't understand how mine works as it returns to the filter, but most go back to the tank. I've known one example of a return which was just a skin fitting in the top of the tank and it aerated the fuel inside - when low it could suck up the freshly aerated fuel.