Yanmar 4JH4AE Fuel Water Separator question

[miraculix]

Hi all,

This is my first round of maintenance on our 2008 Beneteau 40 we bought last summer. Our engine is a Yanmar 4JH4AE.
So far, I replaced the raw water impeller and the V-belt. The V-belt was pretty loose, and there was a lot of grit on the V-belt cover and engine parts behind the belt cover. I check the V-belt every time I start the engine. With the V-belt cover on, I got it totally wrong every single time I checked. That made me thinking to leave the V-belt cover off.

Anyhow, my big question is the water separator. The fuel system diagram shows the water separator between the tank and the fuel pump in the engine manual. In the boat, it's located in the rear of the engine compartment.
The engine manual only describes regular draining of water and debris from the water separator, nothing else. The water separator housing is black, so I cannot see if there is a filter inside that would need to be replaced.
There is no maintenance record of the boat. I do not know what maintenance the former owner had done. However, in a spare part box, I found a filter element labeled "fuel filter" (not the one behind the fuel pump). A diagram in the manual seems to show a filter element but somehow did not describe a filter to be changed during regular maintenance.
In other water separators, I have seen there is always a filter element that needs to be changed, so I am a little confused here.

I appreciate any advice.

Thanks,
Christoph

 

[JoeWhite]

Yes, there is a filter that should be replaced every other season or 250 hours. Take it apart and see if there is a filter there now. Also provide it's model number.

 

[sail sfbay]

The first maintenance item on any new / used boat is fuel filter replacement and biocide treatment of the fuel to mitigate the risk of fuel delivery plugging and engine shutdown. Of course, there are other causes of fuel system pluggage such as tank fuel pick-up line, etc.to inspect.

 

[jssailem]

This is my first round of maintenance on our 2008 Beneteau 40 we bought last summer.

Ahhhh... reaching another milestone in boat ownership. Congrats.

There are several different types of manufacturer provided "water separators". Racor is a popular design.
My boat came with a Ford Motor designed water separator.

I removed it because the design did not let me know what was up with the fuel quality. Besides it was extremely messy spilling diesel when I was trying to change the filter.

I chose the Racor as it provided the needed design I desired.

There are a number different designs of Racor. The 500MA is CG approved for use in an engine compartment. Filters are easily replaced from the top. I've got the process down to about 7 minutes no spills. Practice with old fuel in the tank that has a bit of growth helps to give you practice opportunities. The engine shutting down while you are in a channel helps to give speed incentive to your filter changing skills.

A clogged Racor filter that will stop your engine due to fuel starvation looks like this.


Good luck. Your maintenance today may save your bacon tomorrow.

 

[miraculix]

Hi,

Thank you all for your input.
I hindsight I realized that I should have done all that the first time after I bought the boat. I got lucky, nothing happen.
I am on the way to the boat and have a chance to find out. Again, this is my first rodeo, not with engines in general, but with boat diesel engines.

Thanks
Christoph

 

[miraculix]

Hi all,

Here is a view on the things in question. The screenshot is from my engine manual. It shows the water separator, down left (1) the screw for draining and on top (2) the screw for air bleeding. I am wondering how to open this. I have the feeling that the screw dow in the middle is the way to uninstall.

Thanks
Christoph

 

[jssailem]

I would guess your manual describes the procedure.

1. Shut the fuel flow valve. No good spilling more fuel than you need to.
2. Get a container to hold the fuel in the filter/water separator and a bit more
3. Lay a fuel pad or two to capture any spilled. You will spill at some point
4. Put on some gloves
5. Acquire a box wrench the size of the bottom center nut. And one for the bottom drain nut. And a third for the top bleed nut. All the nuts may use the same size wrench but they also may not. Be prepared.
6. First step is to drain the filter into the container. You closed the supply valve correct? Remove the drain nut and open the bleed nut
7. When fuel stops draining (remember you closed the fuel supply valve. If not your container will over flow. Shut eve and close the supply valve!) set aside the container in a safe place where you can not step on it or spill it
8. Now unscrew the bottom center nut. This will eventually drop the fuel filter container. Catch it before it falls loose
9. Set the bolt safely aside. ( I like to have a separate container to put all of the parts into as I take them off. Then I know where all the parts are to put the bigger back to.
10. When the filter housing come off likely the filter will come with it. Look inside the bowl and remove the filter from the center bolt. Set the used filter in a plastic bag for disposal
11. Check the contact points or the bowl for O rings or gaskets. You will need replacements that should be in the box with the filter. If not you need to find replacement O rings and filter gaskets before reassembly.
12. From this point we star in reverse reassembling the filter unit
13. Put the new filter on the center bolt. Note the spring should be on the bolt that holds the filter in place
14. Place the O rings and gaskets in place
15. Position the bowl so you can thread the center bolt into the upper housing. Careful to get the bolt properly threaded. Use your fingers. If not threading easily you may have cross threaded. Back off and start again
16. With the bowl back in place and snug up against the housing (note firm/snug not as tight as you can turn. ) you can close the drain nut. If you removed the drain nut it might have an O ring. Put on a fresh one of it may use a copper washer. Get a new one as these are a one time use item
17. When bowl is in place and drain plug firmly closed, open up fuel supply. Pump fuel into filter bowl with bleed nut open until bubbles are gone and fuel appears to flow out. “ Now you know why you laid down the fuel absorption pads
18. Close bleed nut
19. Try to start engine
20. When it fires up give a cheer to the engine. They need a little loving now and then

That is the procedure as I remember it. I may have it a bit confused, but I’m sure someone else will correct it.

 

[miraculix]

Hi all,

@jassailem
Thank you very much for this comprehensive explanation. That is very helpful and gives me a lot of reassurance that I was not too far away from reality with my thoughts.
BTW... closing the fuel valve was the first thing I did when I came to the boat.
Unfortunately there was no O-ring in the filter box so I have to check with the marina store tomorrow, but they may not be open due to the holiday.
Anyhow, more important is that I now have a good idea how to do it.

Thanks again!
Christoph

 

[miraculix]

Hi all, I finished the whole thing yesterday afternoon, and it was quite an ordeal. It should have been pretty straightforward with the excellent instruction I got here.
Anyhow, the way the water separator is mounted and the location made it a rather unpleasant experience.
After loosening the central bolt, I could not get the filter housing to come off easily, and I wondered about that already. Some moving the whole thing back and forth finally did the trick, but it really should have fallen off on its own.
I changed the filter, which was almost black, cleaned everything put the new filter in, and tried to mount it. However, I could not get the bolt to catch the thread, and I thought it was due to the rather strong spring and the location. I tried over and over and thought its the spring, and I am just not pressing hard enough. Again, the mounting location makes strong upward pressure and rotation at the same time pretty difficult. I could not really see if there were any other problems.
Finally, I gave up and made a picture with my iPhone from a view angle I couldn't see the whole thing.
Guess what? The hose clamps were mounted in a way that they were hindering the filter housing from going up.

After giving Beneteau a couple of not-so-nice names, I rotated the hose clamps and, from there, threading the bolt was easy. Unfortunately, the housing didn't want to go all the way up. I took everything out again and did another picture with the iPhone to see if anything was blocking the housing from going up. I found that the mounting bracket was overlapping the gasket seating area—reason number two why the housing did not simply fall after loosening the bolt.

I had to tighten the central bolt until the was some resistance and then wiggle the whole thing back and forth with some force until the housing edge jumped over the bracket rim. Then the housing went all the way up and could be tightened against the gasket.
What a genius way to mount this water separator...

Christoph

 

[kloudie1]

Next time ya change the filter, remove the filter top and drill the bracket holes 2 sizes larger.. then when you remount the filter top, push it away from the bracket before tightening the bolts. this should allow the top to move enough to readily clear the filter housing for removel and installation.

 

[JoeWhite]

Excellent write-up with photos to explain the problems. On the second problem my solution would be to remove the bracket and file the center between the bolts to allow easy mounting.

 

[jssailem]

Way to work the problem. It is so great to have a camera to be your eyes and help identify the usual suspects. Looks like the bracket might have been a solution created by a previous owner. Made it almost better to get at the fuel filter. I would consider cutting off the offending end of the bracket, back to short of the filter housing rim. Then you have no issues. Or you can cut (grind out) a partial circle in the bracket to make the filter housing fits. "Blue Line", perhaps a better solution as the nut and washer holding the bracket to the filter housing looks rather stout.