Changing fuel filters on the Universal M25 diesel

How to change the Racor R24T primary fuel filter

1. Turn the valve at the fuel tank to shut off the diesel fuel supply.
2. Put paper towels or rags or something absorbent under the filter, there will be fuel spilling.

3. Use the screwdriver to open the vent screw on top of the Racor fuel filter/water separator unit. Just open it. Don't take it off.
   • The vent plug is the small screwable plug on top, not the large screwable plug that is to the right of the large knob.

4. Get ready with your container. The large red plastic cup shown in the photo is NOT quite big enough.
5. What plug is the drain plug?
   • Good question, tried undoing the knob first and nothing came out
   • Called Racor tech support to find out which plug on the bottom was supposed to be the drain. He said the small one you take off with a screwdriver. Hmmm, I don't think so - you would think the knob you can unscrew with your fingers would be the drain plug for this common task. Oh well, it wasn't draining out of the big one so...
6. Use the screwdriver to unscrew the drain plug from the bottom of the separator bowl and drain it. Don't lose the plug!

6. If you can't get the filter off the unit by hand, use the adjustable swivel band wrench to loosen and then take it off.
   Take this over to your huge work bench on the boat.

7. If you can't get the bowl off the filter by hand, use the band wrench to loosen and then take it off.
8. Clean out the bowl with some clean diesel on a paper towel. Screw the plugs back in the bowl.
   Close the vent plug on top of the Racor unit while you have the screwdriver in your hand.

9. Open your new Racor R24T and the package of new O-rings that came with it.
10. Use your finger to put some fresh diesel all around on both of the new O-rings and put them on. You don't need to be stingy with this.
11. Screw the separator bowl onto the new filter. Hand tight SHOULD be all that is necessary. Make sure there aren't any gaps between filter and bowl.
12. With new filter-and-bowl held over an empty receptacle for clean fuel, fill the filter with enough fuel to check the o-ring for leaks.
    • No leaks? Good, fill the filter ALL the way to the top.
    • Leaks? Dump the fuel back in the container and check the bowl fitting onto the filter. Here's my experience with the bowl o-ring leaking - After 3 tries with the new filter, then re-assembling the new o-ring with the bowl and old filter to make sure I wasn't crazy (it didn't leak), and trying again with the new filter (which still leaked), I went out and bought another new filter.
13. Carefully carry your filter filled with fuel over to the unit and screw it on. Hand tight is all that is necessary.
14. Did you close the vent plug on top of the Racor unit?

How to change the secondary fuel filter (the one on the engine)

I had to make a trip to West Marine for another new R24T filter, so didn't get to the secondary fuel filter on the engine this time.

How to bleed the fuel system after changing the Racor primary filter

If you had your fuel filter FULL to the top when you put it on, you shouldn't have to open the bleed nut or injectors to bleed the fuel lines.

1. Open the fuel tank valve.
2. Turn the ignition key on, but don't try to start it. You should hear clicking from the fuel pump as it pumps fuel. Keep the ignition on for 2 minutes. Meanwhile, check for leaks.
3. Start your engine
   • Push your glow-plug button in for 30 seconds
   • Push Start button
   • Yay! Starts right up!
4. Check for leaks!

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Getting rid of the old fuel

Most marinas have a recycling area for disposal of old fuel and oil. Antifreeze, no. Check Earth911.com for recycling centers near you.

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Other resources about fuel filters

• Here's my original spec sheet on the Racor 20 Series Spin-On Fuel Filter Separator.
• A better spec sheet that shows the drain plug Racor 215R 230R 245R Spin On Series.

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Related topic: Dirty fuel filters