Diesel filter question.

[Jeff Asbury]

Diesel filter question.

As some of you may have read, about a month ago I thought I was going to have to replace my fuel tank. After replacing the old narrow copper lines from the tank with new rubber hoses and new barbs it seems to be okay.

My question is that for the past 9 years since I have owned the boat I had always been under the assumption the little brass pipe under the clear bowl on my Racor primary filter was used to inspect the quality of the fuel in the filter. Such as being able to hold a cup under the pipe, push up on the pipe to release some fuel to see if there is water, sludge or particles in the fuel.

Now after about 15 hours of running time I decide to push up on the pipe to check the fuel. Nothing comes out and if I hold it open long enough bubbles will go up from the pipe in the clear bowl. I asked my mechanic friend why it was doing that and he said that was good and that I probably have a vacuum. I swear he was the one that told me many years ago that it was used to inspect the fuel and fuel should come out.

What I am worried about is that there still may be a clog in the tank and that is what's creating the vacuum before the filter.

I hate to question my mechanic but I would love to hear other opinions before I go to the trouble of disconnection the fuel line to test it and having to bleed the lines again.

Thanks in advance. See the pic.

 

[Tom Metzger]

Did you open the vent? Generally you have to do that to get anything out.

 

[Jeff Asbury]

Well I never had to open a vent before. Where is the vent? Is it the big nut at the top? Oh wait, I remember seeing a nut on the front, top, center with the word "vent".

Well thanks Tom. That's making sense now. I am just a bit mystified that I never had to open that before. I won't have to bleed the lines again if I do so, right?

 

[Tom Metzger]

Jeff - If you have a priming pump on the filter operate the pump with the vent open until the filter is full.

If you don't have a pump the instructions are on this instruction sheet pages 3 & 4.

http://www.parker.com/literature/Racor/12945_Rev_A_120RMAM_Series.pdf

I hope this helps.

 

[Jeff Asbury]

Thanks Tom, I'll check it out. I have a priming lever on my fuel pump on the Yanmar, not on the Racor.

 

[bayhoss]

Jeff, I have the exact same filter and fuel comes out when I open the bottom valve without me doing anythinng else.

Best,
Frank

 

[Jeff Asbury]

Thanks Frank, that's what I have always thought and had experience with. I am planing to disconnect the fuel line that goes from the tank to the Racor this weekend and make sure it's flowing just to make sure nothing's stuck in the tube that goes down into the tank again.

Then I got to re bleed again.

"Let It Bleed" - Jagger / Richards 1969

 

[cawinter]

Comment

I typically shine a flashlight from the back to judge the amount of gunk in the filter bowl. Usually looks nice and golden

As far as the bowl, etc. goes, I disassemble the bowl wnd clean everything out every year as I change the filter element. I also recirculate the remaining tank content (5 gal?) through an automotive-type fuel filter (20u ?) for a while before pumping the tank dry for the winter. Even though there remains a bit of 'smear' on the bottom of the tank, it never seems to find its way into the bowl. Of course, that is NOW. Years ago, the P.O. left me with completely gunked filters that I had to change twice per season.

I am not sure if I can drain from the bottom drain without opening the vent screw up top. I never had anything obscure that needed to be taken out. Lucky me, I guess...

 

[jmcpeak]

That is one pretty engine compartment. Clean, noise shielded, didn't come the factory like that, did it?