Sail, what follows is a text I composed intending to post as a new thread. I decided to tag it on here instead. You're tutorials are well illustrated and well written, thanks for the effort. They really help someone like me who does all my own work but is new to diesels and boats.
This post reads like a new thread post so flows a little awkward here. I added slight edits for clarity.
The bowl on my Racor 500FG was literally half full of silt so I decided it must be attended to. It wouldn't drain at all, and little could be done from the opening for the drain. It's the older style FG where the bowl is inserted from the top when the unit is mounted. It doesn't have the removable retaining ring like the newer model. The retaining ring is actually the mounting bracket as well. So I decided to remove it for servicing and starting looking for info to fuel an effort to disassemble and rebuild
it using kit RK 15211 that I purchased from West Marine
for double what it should have cost.
I found this thread on the forum, Cleaning Racor 500 FG Filter - Problem !
, and read it with interest. (edit.... this is the thread you are reading now.)
I also read this tutorial published online by a member
(edit....Maine Sail) of the forum. Of particular interest are the images
of the check ball seal halfway down page one. Rebuilding A Racor Turbine Filter Photo Gallery by Compass Marine at pbase.com
I question the orientation of the check ball seal. Mine appeared to be upside down based on the image labeled as correct from the tutorial. While reassembling the unit I came to question whether it should be installed as shown in the tutorial.
This image is labeled as the correct installation
orientation for the check ball seal. (#10 item 15010)
Check Valve Gasket - CORRECT photo - Compass Marine photos at pbase.com
This is the section drawing included with the kit and shown in the tutorial.
Exploded View photo - Compass Marine photos at pbase.com
Three things cause me to question the accuracy of the image labeled as correct for the seal.
- The seal is labeled “top” in that image yet it is oriented in a way that this label is actually on the bottom when the unit is in the upright position. Of course it is the top when the housing is upside down as in the picture.
- The section drawing shows the lip of this seal in a way that suggests the label “top” would actually be on the top when installed upright. A careful look at item 10 in the magnified view shows this clearly. (in the circle next to the words All Models in the center of the image) Notice the curve of the "dish" just to the left of the tip of the arrow for item 10.
- My old seal was oriented with the label “top” on the top when installed and my filter may well have never been disassembled. It has been working properly I suppose, since this check ball prevents the system from losing prime and mine has not lost prime.
Granted it does appear to “fit perfectly” in the dish as stated in the next frame of the page. However I'm not sure that is a reason to place it that way for two reasons. It contradicts the “top” label (unless held upside down) and and section drawing (clearly). Also since this check ball literally floats up against this seal it would work best with a contact surface that is thin, much like a floating needle and seat in a carburetor. Having a wide contact surface offers more opportunity for contamination to foil the process. This is the unfiltered input to the bowl so grit is there if anywhere.
I believe it's dished in order to thin the contacting edge against the ball. Making it more supple or compliant, to seal on the floating ball that would not press very hard against it. It flexes and seals
more easily against this thin supple edge and small force as a result.
Look carefully at the curved line on the section drawing that represents the “dish” and consider my reasoning from the last two paragraphs above and see if you agree.
I present this as an honest critique and not to disparage your efforts on the tutorials, they are excellent.