Racor filter question

[leecea]

I'm sure this is documented somewhere but I have tried to find it and can't.

When I watched a mechanic change my Racor filter he filled the new filter with diesel before screwing it on. But my Racor has a plunger style pump on it. Why can't I use that to fill the filter? How would I know when to stop pumping?

Also, after changing the secondary filter on the engine, he used the small manual fuel pump lever to pull fuel through the system and out the bleed screw. It was slow. Would it be easier to use the plunger on the Racor to force fuel through?



Thanks,
Andy

[markxengineerin]

There's no such thing as over-pumping, and no harm in trying any possible method to find one that works for your boat. If the manual methods take too long for your taste, you could install a small lift pump, which makes quick work of bleeding air. I find the manual pumps to be slow and sometimes unreliable, no patience for that kind of thing.

[Calif.Ted]

A. Introduces less air into the system to be bleed out at a later point if you fill the filter.
B. I find Racor pump is easier to use in that it moves a larger volume, but I switch to the mechanical on engine pump lever for final stage after everything seems bleed.
It takes a lot of pumps to fill the filter if it's empty to start and that air goes exactly where you don't want it.

[Jammer]

Originally Posted by leecea

I'm sure this is documented somewhere but I have tried to find it and can't.

When I watched a mechanic change my Racor filter he filled the new filter with diesel before screwing it on. But my Racor has a plunger style pump on it. Why can't I use that to fill the filter? How would I know when to stop pumping?

The pump is small and a nuisance to use. Much easier to at least start by pouring some diesel into the filter.


You stop pumping when there's no more air.

Also, after changing the secondary filter on the engine, he used the small manual fuel pump lever to pull fuel through the system and out the bleed screw. It was slow. Would it be easier to use the plunger on the Racor to force fuel through?

Who knows, maybe. Whatever works. There are old and new Racor pumps and the new ones are better but still slow also. Key point is to get the air out one way or another before it gets to teh high pressure pump.

[DoubleD]

I have the filter you show in the picture. As others have mentioned, if you fill the Racor and secondary on the engine with fuel first, you need to manually pump less. To my surprise, for my Yanmar 3GM30F, I was able to push fuel from the Racor past the secondary on the engine, with the Racor pump. If you want to see how to know you've removed the air in the system, there are many youtube videos. I found this one to be useful for my setup.

https://www.youtube.com/watch?v=ub0zfW42mVo

DD

[desodave]

I'll go with whatever works best for you. We had a Hunter with a 40hp Yanmar and would always fill the Racor bowl because , if you filled the bowl before putting it back on, the engine would always start without bleeding the injectors. Same with the primary fuel filter ... put it back on full and no bleeding required. If you put it back on without filling the new filter, I always had to bleed it. Not sure I can answer why to use the small lever on the engine, but it was a closer and more convenient reach than using the Racor pump on my old engine ... given that you're loosening a bleed screw and watching for air bubbles at the same time. You're effectively putting a big hunk of air into your fuel system when you screw on an empty filter, then having to bleed it out again.

[Chotu]

both methods work just as well. He’s just trying to save a little time. He probably does this often. It’s faster to get a head start.

all the air will get purged eventually. Might as well have a little less air to purge.

[leecea]

Thanks everyone - this is all really useful info and I think I understand the whole process much better now.

[sailingharry]

I had that same rancor filter on my last boat. Two important comments.

First, that black knob on top that is a priming pump. If you don't screw it all the way down, it provides a restriction on flow. Took me close to a year to figure out why my engine would periodically just die!

Second, that filter body takes three different filters, small medium and large. No other difference in the body. The large filter is maybe 10% more expensive than the small, with double the sediment capacity. If you can fit the large, go for it.

[sailingharry]

As a follow up, here is the manual. You have the "mid size" filter element. At the bottom of page 42, you can see that the large holds 50% more dirt. On page 41, you see the large filters are the R25 series, vs your R20 series. West charges $40 for the R20 series, and only $50 for the R25 series -- a bargain in my book. Of course, those are West priced -- the R25T is $30 on Amazon.

https://www.parker.com/literature/Ra...200_Series.pdf