Fuel Filtering

   

Vacuum Gauge

    As our time left for departure is coming to an end, so is the time for any last-minute projects. There really isn't much more I can do. But one very simple project but pretty important has to do with one of the most likely engine failure issues. Fuel, more specifically, fuel filtering.

    I blogged about this in The Importance of Clean Fuel when I was going over the engine early on. I now wanted to take it one step further. With a single engine, clean fuel is even more important. If an engine is going to fail, you can be sure it will happen at the most inopportune time, like in rough seas or during docking. I wanted one more level of security.

    You cannot always tell if a fuel filter is ready to change just by looking at it or by the amount of time it has been installed. The surest way is with a vacuum gauge. Installing this gauge should pay for itself by not wasting money replacing filters that are still good.

    So how does it work? Pretty simple, any obstructions, water, dirt, etc. in the filter (or before) will result in a higher vacuum reading on the gauge. The gauge is installed after the filter but before the lift pump. The gauge should be read when the engine is under load. Every engine is different and it's important to know what the "baseline" is, in other words what the "zero" reading would be. Typically, between 0 & 10" Hg, but when it reads higher than that, it is time to change out the filter. 

    As stated, the gauge should be read when the engine is under load. To make that easier than climbing down into the engine room underway, some gauges come with an additional drag needle that will stay in place when the engine is shut off so that you know what the highest reading was when the engine was in running.

    Now to the install. The Camano has a Racor 75B32016 Dual filter with a selector to choose, left, right or both filters.

    In order to install a vacuum gauge, a little "engineering" had to take place. There is not enough headroom over the top of the filter(s) to install directly on top. Here is the final result.

    I can't take credit for the install, a friend of mine who is a first rate diesel mechanic did the install. He also went over the entire fuel system and explained how to deal with "repriming" the engine if needed.

    I also intended to install a gauge on my generator Racor but my good friend Tony Athens from Seaboard Marine said that the fuel doesn't flow enough to register on the gauge and that I'd "be way better off installing a bulk separator before the Racor with a drain such as a Fleetguard #FF5013".