Change filter and bleed. Scared!

[joeniver]

I am kinda nervous to do my first "on engine" fuel filter change. Please let me know if the following steps are correct for doing the change and bleeding the line to the filter and to the injector pump. I was told by PO that I should not have to bleed at the injectors.

Any comments, critiques, suggestions, Hell-Nos sincerely welcomed.

Yanmar 3HM F


Step 1:
Turn off engine. I know it is working.

Step 2:
Presoak the new fuel filter in a clean jar of diesel fuel. I know that they recommend to fill the cup with diesel after putting the new filter in, but I am adding a little insurance by doing that and pre-soaking.

Step 3:
Take off fuel filter cup from engine. Remove old filter, trying not to add air to fuel left in the cup.

Step 4:
Put new filter into container and add diesel fuel to the very top.
Go slow so no air gets into the container or into the filter. Tighten container.

Step 5:
Open bleed screw on fuel filter and pump lever on lift pump till all bubbles stop coming out. While continuing to pump, close bleed screw on fuel filter cap. I believe that the bleed screw is the one in the back, nearest to the block?

Step 6:
Open bleed screw on injector pump while pumping lever on lift pump. Continue pumping til no more bubbles come out of the bleed screw on the injector pump. Close bleed screw while pumping.


Step 7:
Start engine

See pictures below

[CassidyNZ]

Hell yes. I’ve never pre-soaked a filter but that’s sure to help as well. And the OP is correct, Yanmars self bleed. Once the engine is running it will workout any residual air in the system.

Don’t over-think this - air bubbles are not a death knell

[cabo_sailor]

My first suggestion would be to stay calm. Bleeding the fuel system is a pretty common chore and if you mess up; no harm. Just start over.
Second, I expect on the Yanmar you will have to crack the injectors. Just takes a moment.
Along those lines while it’s good to keep as much extra air out when changing the filter no need to go crazy. The bleeding process is what takes of the excess air.
There IS one caveat. If when you crank the engine to bleed the injectors, try not to crank too long. Crank too long and you might suck water into the engine. If needs must you can TEMPORARILY close the engine raw water thru hull. Just remember to turn it back on when the engine fires. Frankly, in 25 yrs I’ve never had to do that so it’s just something to keep in the back of your head.
My first boat had a Yanmar and with practice I could bleed it in less than 10 min.

[cabo_sailor]

Originally Posted by CassidyNZ

Hell yes. I’ve never pre-soaked a filter but that’s sure to help as well. And the OP is correct, Yanmars self bleed. Once the engine is running it will workout any residual air in the system.



Don’t over-think this - air bubbles are not a death knell

Are you sure about Yanmars self bleeding? Mine was a 3 cylinder from maybe the early 80’s and it certainly had to bleed the injectors. My current Westerbeke 46 supposedly doesn’t need bleeding but for a couple minutes with a wrench it sure helps.

But your definitely right to suggest don’t overthink it. Apologies to the OP but I had this picture of a bomb disposal procedure with sweat pouring all over [emoji849]

[CassidyNZ]

Originally Posted by cabo_sailor

Are you sure about Yanmars self bleeding? Mine was a 3 cylinder from maybe the early 80’s and it certainly had to bleed the injectors. My current Westerbeke 46 supposedly doesn’t need bleeding but for a couple minutes with a wrench it sure helps.

But your definitely right to suggest don’t overthink it. Apologies to the OP but I had this picture of a bomb disposal procedure with sweat pouring all over [emoji849]

It’s been 20 years since I owned a 3GM30 but I had it for several years and don’t recall cracking injectors to bleed. A friend has a 2GM and I’m reasonably sure it also doesn’t have to be bled at injectors. My 4JH4E certainly doesn’t, I pump with an outboard bulb (which I have inline) until I get fuel at the secondary filter bleed screw, start up and it runs sweetly in a few seconds.

[a64pilot]

Originally Posted by cabo_sailor

Are you sure about Yanmars self bleeding? Mine was a 3 cylinder from maybe the early 80’s and it certainly had to bleed the injectors. My current Westerbeke 46 supposedly doesn’t need bleeding but for a couple minutes with a wrench it sure helps.

But your definitely right to suggest don’t overthink it. Apologies to the OP but I had this picture of a bomb disposal procedure with sweat pouring all over [emoji849]

My 30 ur old 4JHE will run happily if I just put a new filter in and not even bleed the housing, so long as I don’t drain the bowl, it just eats the air, so long as it gets enough fuel with that air it clears it out.

[Cool Hand Luke]

Holy freaking crap! I was just going to make a post about getting help on bleeding my 3JH5E. I'm also very afraid about changing the fuel filters (primary and secondary) and bleeding the system after. But I was reading the manual and it also said that it doesn't need to be bled. But, seriously??? It literally says to bleed after filter change. PAGE 38:

https://www.yanmar.com/media/global/...JHM-M00201.pdf

I'm also very afraid and now thinking of the bomb squad with sweat running down analogy

Anyone want to walk me through it via FaceTime or Skype? I'll pay for your time

[ChrisseH]

I have never bleeded my Yanmar 3JH4E when changing fuel filters. Just run your engine warm, stop the engine, change one of the filters and restart. In 15 to 30 seconds the fuel pump has sucked out all air from the fuel line and the engine is running smoothly again. This works both when changing primary and secondary filter, at least when changing one filter at the time.

[DanaTucker]

Originally Posted by joeniver

I am kinda nervous to do my first "on engine" fuel filter change. Please let me know if the following steps are correct for doing the change and bleeding the line to the filter and to the injector pump.

You should have no problem if you follow the steps you listed in your OP. My only added advice is to have a couple of baby diapers on hand to absorb the fuel during the bleeding process.

Originally Posted by Cool Hand Luke

I'm also very afraid and now thinking of the bomb squad with sweat running down analogy . Anyone want to walk me through it via FaceTime or Skype? I'll pay for your time

Send me a PM on when you can be available. Your process is a piece of cake, according to your manual, page 38. I have downloaded your specs. Just make sure you have a set of good open/boxed end wrenches and a pack of diapers. I have my own online conference room we can use, I don't do skype. There will be no charge. Most boaters never accept monies for helping other boaters.

[Chotu]

You'll be just fine.

My old YM30 (or similar) process was:

1) pull off the filter

2) install dry filter with air and empty bowl full of air.

3) crack bleeder screw at highest point in pre-injector pump fuel system (low pressure side)

4) finger pump the low pressure side full of fuel again until no more bubbles out the bleed screw

5) start and run the engine normally


Never any problems at all

[ranger58sb]

Originally Posted by joeniver

Step 2:
Presoak the new fuel filter in a clean jar of diesel fuel. I know that they recommend to fill the cup with diesel after putting the new filter in, but I am adding a little insurance by doing that and pre-soaking.

We've been instructed to NOT allow unfiltered fuel to a diesel engine. "Clean" new diesel is not filtered. Might be overkill, and I know bazillions of folks use "clean" (but unfiltered) diesel to pre-fill a new filter... but we've chosen to follow the more cautious instruction.

FWIW, our genset uses a 3-cyl Yanmar maybe similar in some ways to yours. Electric fuel pump. Bleeding is easy, only necessary at the fuel filter, and works just by bumping the start switch (but not actually starting) until the filter is full.

-Chris

[GordMay]

See Section 9-1, of the Yanmar Operations Manual ➥ http://j30.us/files/yanmar-manual.pdf

[a64pilot]

Originally Posted by ranger42c

We've been instructed to NOT allow unfiltered fuel to a diesel engine. "Clean" new diesel is not filtered. Might be overkill, and I know bazillions of folks use "clean" (but unfiltered) diesel to pre-fill a new filter... but we've chosen to follow the more cautious instruction.



FWIW, our genset uses a 3-cyl Yanmar maybe similar in some ways to yours. Electric fuel pump. Bleeding is easy, only necessary at the fuel filter, and works just by bumping the start switch (but not actually starting) until the filter is full.



-Chris

Your correct, all it can take is one particle to be the magic bullet and make a scar, yes that is very unlikely, but why risk it?
The other thing is hear about that gives me the willies is that some people will use straight injector cleaner thinking sending it in pure is a good thing.

[sirfer]

Remember to shut off the fuel supply before removing filter...and open it again before starting engine...

[boatpoker]

Originally Posted by ranger42c

We've been instructed to NOT allow unfiltered fuel to a diesel engine. "Clean" new diesel is not filtered.

It is filtered by the time it gets to the engine unless you bypass your new filter and I can't see why anyone would do that.