How to tell when filter needs replacement

[bazzer]

I have two inline Racor filters and a engine mount filter on my Volvo MD17c. How do I know when they need replacement? What size elements should I use?

[gts1544]

I would recommend changing your primary (read first in line) Racor filter annually, unless more frequently required, such as after a rough passage stiring up the sediment in the bottom of your fuel tank. Be aware that Racor has filter elements of different sizes and filtration (microns) depending on the size of your filter and use. You can also install Racor differential pressure gauges on the top of your Racor filter units and follow their guidelines on when to change filters. Filters are cheap in the grand scheme of things.

[bobconnie]

I keep records on filter changes, I change primary racors yearly,secondary racor as needed. I change engine filter, which is the finest micron filter in the system, twice a year! I always add a tank drain in the bottom of any fuel tank I own, and drain any water from the tank at least once a month if sitting, more offen in rainny weather. seems to work for me. at least it has so far, I do know yhat having an engine room log helps me to remember whats been done and helps to sell the boat when I want to!! just my 2 cents

[noelex 77]

Two primary filters for the main engine(which is what you have assumining one is not for fuel polishing or a generator) can be plumbed in two different ways.

1. To use both filters together the first filter is coarse, usually 30 micron, the second is fine, usually 2 micron ( occasionally 10)

2. So you use one at a time and can switch immediately if one plugs up. In this case they are both the same, usually 10 micron.

Tracing the plumbing should reveal which one of these set ups you have.

[jeremiason]

Since we started cruising on the Pacific side of Mexico and Cental America we have been racking up more engine hours than when we were in San Francisco...

We have three fuel tanks with a Racor 500 unit with 10 micron filters on each tank.

The only filter that has failed had over 600 engine hours before fouling.

In my opinion, if you have a Racor that allows a vacuum guage, you might want to invest in one, since over time you will save on new filters by installing new ones when need, instead of annually.

[djmarchand]

The fuel system is under vacuum upstream of the on engine fuel pump. Racor has a vacuum gauge that you can screw in to the top of the filter. When the filter is new there is little pressure drop across it so that the vacuum is low (meaning closer to atmospheric). When the filter starts plugging up the pressure drop increases so the vacuum gets higher. The gauge has green, yellow and red bands. When the vacuum gets near the red it is time to change.

Your on engine filter is probably 2 micron. Therefore you want your Racor to be larger- 10-20 microns.

David