Primary Fuel Filter change out

[britinusa]

Time to do another oil change and while at it I intend to change out the Racor Fuel Filter system. (I've had the new one sitting ready to do the change out for a while, it's time.)

I have read dozens of threads and pages on Bleeding the system after a fuel filter change, the site here has plenty to read on the subject.

As I'm changing out the filter assembly, pretty sure I'll need to bleed the fuel lines.

Putting all that I have read into place, how does this sound for the replacement process.

• Shut off the Fuel cock at the top of the tank
• Slacken the Racor Fuel Filter
• Coffee can used to catch any spillage
• Remove the Filter - Discard
• Remove the supply line (in) to the old Filter Assembly
• Remove the delivery line (out) from the old Filter Assembly
• Unmount the old Filter Assembly
• Add an inline shut off cock to the supply line (in) to make it easier for future filter changes
• Mount the new Filter Assembly
• Connect the fuel line from the new shut off cock to the filter supply (in)
• Connect the fuel delivery (out) line to the new Filter Assembly
• Put new filter in coffee can and fill the filter with Injector cleaner
• Pour some Injector cleaner into the new Filter
• Install new filter into the new Filter Assembly
• Hand tighten filter to Filter Assembly
• Open fuel shut off cock on top of tank
• Open new fuel shut off cock by Racor Filter
• Turn on Engine Ignition (and Cabin Engine master switch)
• Electric fuel pump should be running
• Open bleed valve on top of new Filter Assembly
• Wait max of 30 seconds for air to escape (take a break for another 30 seconds before retrying)
• Once air is bled from Fuel Filter - Close off Filter Bleed screw
• Turn Ignition switch off
• Get access to Fuel Injector Pump Bleed Screw (engine stbd side)
• Crack the screw open
• Turn Ignition switch on
• Watch for steady flow of fuel from Fuel Injector Pump Bleed Screw
• Once stead flow, close the bleed screw
• Let pump run until click rate subsides - all air should now be out of the limes and returned to the fuel tank.
• Turn off Ignition
• Proceed with the Engine Start process

Did I miss anything or doing anything unnecessary?

Paul

[KWKloeber]

YBYC, but I've never never ever done anything but slap in a cartridge, key the lift pump, and open the bleed knob and bleed until I get a steady steam.  I have my bleed discharge nib  "open" and catch fuel in a cup so I can see what I'm getting (false sense of security, probably?)

I have a SPDT momentary on/off/on toggle switch to install in the engine space so I can crank the starter or run the fuel pump from below.

kk

[tgsail1]

Looks great. Two comments. I've never done 12, sounds messy and smelly. I assume the purpose is to saturate the filter to clear out any air. You have an M25-XP? Leaving the bleed nut cracked for a while should do the same thing. I can't see why you wouldn't leave it open for the entire procedure after 18.  I don't know how you accomplish 26. You could disconnect the return line and run the hose into a bucket or just listen for the clicking pattern of the pump to change (I think it slows down when there no air) and let it go a few minutes after that. You might want to rig a separate fuel pump switch for this (either a temporary jumper or permanent)which you can access from below. Costs a few buck and makes it so you don't have to run to the cockpit and listen to the OP alarm. Also, I don't know which Racor system you are using- some have a manual pump on top for filling the bowl, others you have to fill manually (accomplishing 12).  Coffee cans are great for catching spilled off diesel, but can be difficult to position. Spread out a large garbage bag underneath to catch any missed drips. Overall, your procedure seems sound to me.

[Stu Jackson]

Paul,

Congratulations for doing your homework and then asking first!!!

You might be able to screw the new fuel shut off valve right into the housing of the assembly without removing it.

Filling the new filter with diesel fuel is messy at best, unnecessary at worst.  Ken Heyman's Bleeding 101 topics covered that:  he did a test and found that if you simply leave the knurled knob open longer the fuel pump will fill up the new filter; don't bother transferring smelly diesel fuel if you don't have to.  Personally, I just use the occasion to dump some fuel injector into the new filter to reduce the amount of air and service the injectors that way.

Don't bother with messing with the vent on the top of the filter housing (#19), the fuel lift pump will do it all for you.

KISS.

#26 is wrong.  You do NOT see anything, if you do see anything, you have problems, Houston.  All you do is GENTLY turn the knob counterclockwise and listen for the clicking.  When you close the knob, if and eventually when the clicking slows down, you ARE finished bleeding.  Start the engine.  You are not really "opening" anything, just turning it.  You may have to open and close it a few times to get the slower clicks of the OEM fuel pump.

[KWKloeber]

PS,

If you haven't already, take the opportunity to clean and or replace the Facet lift pump filter NAPA p/n is on the Wiki.)  Also make sure that the Facet is drawing fuel thru the primary (i.e., it's between the primary and secondary ) , and not pushing fuel through the primary (i..e., it's between the tank and primary.     )

kk

[Ron Hill]

Paul : Disregard the bleed screw (always!) to the injector pump - unless you are replacing the injector pump.
 
Also Disregard the filter screen in the electric fuel pump - unless your system is set up with the electric fuel pump before the Racor filter.  The correct plumbing for the fuel lines is : tank to Racor filter, to Racor filter to to electric lift fuel pump, lift pump to engine mounted fuel filter.  That way the electric pump receives filtered fuel!!

I always screwed the bowl onto the filter cartridge and filled the cartridge (and bowl) with fresh fuel or injector cleaner. 
Reason : why ?? introduce known air into the fuel system?  Even thought the bleed screw should?  bleed the air thru the system!!  Plus it's easy to do!!  I also do that for the engine mounted filter.

A few thoughts

[KWKloeber]

PS:  Paul the reason I say change the Facet filter is that mine was always plumbed correctly (after the primary) and so  I never thought about it.  I did remove it whilst I rewired to the pump, and it was full of crap.  Where from? Who knows, but if you take the care to change it once, you won't have to ever worry wmout it again. I wish I had done it when I first got her because I had some fuel/starting issues that may have been from that!  You never know what a PO has done (or not).

Ron's boat, Ron's choice! YBYC. LOL

Kk

[Jim Hardesty]

I use a paint roller pan for jobs like that to keep the mess and dirty parts contained.  Find a plastic one that's got the smallest ridges for easy clean up.  I keep it on the boat all the time and use it often.
Jim

[britinusa]

Thanks guys.

I do not understand how the air is bled from the filter without cracking the bleed screw on the top of the filter, although in my mind, cracking the bleed screw on the injector pump while the electric fuel pump is running (clicking) could bleed the air from the lines all the way to the injector pump input.

One of the videos that I saw (Kabota Engines) described cracking each of the injector nuts on top of the engine and bleeding each line from there. In that instance, they suggested pulling the decompression lever to make it easy to turn over the engine. I figured that if that had to be done, then I should also close the engine raw water sea cock to prevent flooding the muffler. Raising the decompression level would also prevent the engine from starting (important as the sea cock would be closed).

FYI, I have not yet got my eyes on the injector pump bleed screw, so I don't know if it has the bleed valve mod or is still just a bleed screw.

[britinusa]

Almost on topic - Just found this

Paul

[Craig Illman]

Nice animation! Where can I get a turbocharger for my M3-20?

[Stu Jackson]

1.  I do not understand how the air is bled from the filter without cracking the bleed screw on the top of the filter, although in my mind, cracking the bleed screw on the injector pump while the electric fuel pump is running (clicking) could bleed the air from the lines all the way to the injector pump input.

2.  One of the videos that I saw (Kabota Engines) described cracking each of the injector nuts on top of the engine and bleeding each line from there. In that instance, they suggested pulling the decompression lever to make it easy to turn over the engine. I figured that if that had to be done, then I should also close the engine raw water sea cock to prevent flooding the muffler. Raising the decompression level would also prevent the engine from starting (important as the sea cock would be closed).

FYI, I have not yet got my eyes on the injector pump bleed screw, so I don't know if it has the bleed valve mod or is still just a bleed screw.

Paul,

1.  The fuel pump pushes the air out of the lines, so don't open it to introduce MORE air, it's the last thing you need.  The air gets pushed back into the tank through the fuel return line.

2.  From the 101 Topics: Bleeding 101, it says this, here:  http://c34.org/bbs/index.php/topic,6377.0.html

BLEEDING 101

On the C-310 Group Forum on the co.com website, there was a recent discussion about bleeding M25XPB engines. 

Our C34 "Bleeding Headmaster," Ken Heyman, has contributed a lot of valuable input on this process, particularly his "Theoretical Bleeding" article. 

In this reply on the C-310 board I have organized the key links to Ken's contributions.  One skipper suggested cracking the fuel line to the injectors.  Don't do that!!!

There is absolutely NO reason to crack an injector to bleed an M25 series engine. The M25 needs to manually crack the knurled knob, the M25XP is supposed to be self-bleeding but can be done manually.

The newer M25XPB engines have different wiring than the older M25 and M25XP engines, in that the glow plugs are activated by the key switch which is needed to run the electric fuel pump before the engine starts. Key switch, glow plug, fuel pump runs, glow plugs off to start engine, fuel pump STOPS until oil pressure comes up when engine runs. They changed the wiring with the newer engines. To read the details of this strange newer wiring arrangement, dig your way through this looong thread linked in Reply #1: http://c34.org/bbs/index.php/topic,5945.0.html, which goes to: http://c34.org/bbs/index.php/topic,3347.0.html It has a long discussion about how the new wiring works, and concludes with JUST this issue about bleeding.  Critical Upgrades also includes: http://c34.org/bbs/index.php/topic,5078.msg41829.html#msg41829

As far as basic bleeding is concerned, try these:

http://c34.org/bbs/index.php/topic,2884.0.html

http://c34.org/bbs/index.php/topic,5925.0.html and read the embedded links, especially in reply #5.

There is no need to open the vent or the knob on the Racor, either. Let the electric pump do the work. I end up filling the Racor with injector cleaner.

http://c34.org/bbs/index.php/topic,5558.0.html

Your boat, your choice.

Just don't make what is easy into a hard exercise. Please don't reinvent the wheel, either.

[britinusa]

So, do I have this right? ( I have the M25XP )

... instead of bleeding the engine fuel lines, just run the fuel pump and it will push any air in the lines back into the fuel tank via the fuel return lines.

And if the injectors are replaced, then any air will be either returned to the tank via the return fuel lines or injected into the cylinders.

Paul

[Stu Jackson]

So, do I have this right? ( I have the M25XP )

... instead of bleeding the engine fuel lines, just run the fuel pump and it will push any air in the lines back into the fuel tank via the fuel return lines.

No and yes.

It's not "...instead of bleeding."   It IS in itself and by definition  the very process of bleeding, which means getting the air out of the lines, i.e., BLEEDING the air out of the system.

Yes, that's where it goes.

[britinusa]

Thanks Stu et.al.

I have updated my original list of steps.

Paul