Fuel filters & Bleeding M25XP

[kevMar]

Any hints on changing the fuel filter on the universal diesel engine. I noticed that there is not much room there to so without making a big mess... I changed the racor filter last weekend and went very smoothly, but am waiting to do the one on the engine till i get some input from this group...   Thanks for the input...

[Craig Illman]

Ziplock bag surrounding the filter, with an oil absorbent pad under that. Loosen the filter with a filter wrench, remove wrench. Slip the plastic bag over the filter and continue loosening with your gloved hands. Filter drops into ziplock bag, close. Possibly put a piece of pad into bag to soak up the fuel from the filter.  I do the same thing with the Racor. I heard the tip here or on the C36 forum or maillist.

I'm sure others have even more creative techniques.

Craig

[Stu Jackson]

Nothing more than Craig's ideas.  It's a bear to do.  I just use the absorbent underneath.

If you follow the logic, the secondary (engine mounted) filter doesn't need to to be replaced every time you change the primary Racor.  

http://c34.org/bbs/index.php/topic,1124.0.html lists the types and microns of each of the filters, reply #7.

Lotsa posts about the "proper" filter microns to use - search racor and microns

[kevMar]

Do i put fuel in the filter before i put it back on the engine .... or how do i get fuel into the filter and no air

[cmainprize]

KevMar
You do not need to fill the new filter first, but it will make it easier to reprime the system.  I don't fill mine first because I don't want too drop the thing when it is full of fuel.  As far as not getting air in the system, that is not an option.  You will need to bled the system.  I am sure there is a hundred posts on how to bled the fuel system, so i will leave that alone.  It also matters what engine you have.  I have had both the M25 and M35 and they are a little different.

Clean Fuel = Happy Engine

Cory

[Stu Jackson]

There will always be air in the system after you change filters, especially if you don't fill the secondary filter (which I do NOT do).

The only difference is the amount of air, and the fuel pump will eventually get rid of all of it from a primary change with a filled bowl.  I fill my primary with injector cleaner as Ron has suggested.  I do NOT fill my secondary because it's a spill just waiting to happen that I choose NOT to do.  I use the fuel bleed screw on the secondary filter housing.

What you do, as we all have learned over time, is to bleed the engine.

Here's a good link:  Theoretical Bleeding http://c34.org/bbs/index.php/topic,2884.0.html

Many of us have installed fuel pump shutoff switches in our engine compartments, so we can turn off the fuel pump while "down below" like when we've removed the fuel bleed screw on top of the secondary filter to get all that air out.

This is from Reply #10, here:  http://c34.org/bbs/index.php/topic,4866.0.html

The secondary filter bleeding usually, but not always, requires that the bleed screw on the top of the secondary (engine mounted) filter bracket/housing needs to be unscrewed most of the way or completely removed to remove the air from that end of the system.  That's why some folks have installed fuel pump shutoff switches in their engine compartments so they can bleed their engines without having to need either two people (one in the cockpit at the key switch for M25 series engines and one at the engine) or very quick fingers to reinstall the secondary fuel filter screw.  I believe there is a wiki on this.

Even "self-bleeding" M35 engines could well require bleeding if the secondary filter is replaced - I just don't know because I don't have an M35 engine.

I agree that filling the secondary filter, with anything, is almost impossible and shouldn't even been considered, because it requires a three handed four armed left-handed monkey to remove and replace that filter on the lower starboard side of the engine.

Check the tech wiki, and then search on this board the words and phrases  "bleeding", "secondary filter", etc.  There is much material on this subject.

Based on your hull & year you seem to have an M25XP engine.

[Ron Hill]

Guys : I have always professed that you want to fill the filter with fuel - as the least amount of air introduced into the fuel system the better !!   The engine is mounted at an angle so you might only be able to fill the engine fuel filter 7/8 full of fuel, but I fill mine to the top and put a absorbant pad to take care of any spillage.  Air in the fuel line is a "quick stop" to a diesel engine.

You don't need to put a separate electric fuel pump switch down below.  Here's all you need to do to control the electric fuel pump when you are working by yourself :
1. Turn on the key switch
2. Turn on the battery selector switch to 1 to activate the electric fuel pump
3. After you have bled the air out of the system and you want the fuel pump Off, turn the battery selector to OFF - No power No pumping.

A few thoughts.

[Jim Hardesty]

Don't forget to turn off the fuel at the tank.  Maybe it's because I change my filters in the spring and the tank is topped off.  I get a surprising amount of fuel flow if I don't shut the tank off.  I've checked.
Jim

[Craig Illman]

I added a valve at the Racor. It sure beats emptying the lazarette, opening the Beckson cover and groping for the tank valve.

Craig

[Ron Hill]

Jim : I'm not surprised.  The fuel will syphon out of the tank (tank is higher than the Racor).

As Craig mentioned, most of us have put a simple ball valve in the inlet of the Racor.  It sure beats groping for the fuel cut off on the top of the tank thru the port side lazerette.

Another simple way to shut off the fuel that I've written about before, is to use a needle nose vice grips like a hemostat on the fuel line to clamp it shut.  Just be sure that you put some small pieces of hose (or other protection) on the needles of the vice grips so they don't cut/damage the hose.  A thought

[Stephen Butler]

Ron, am sure the data is in the system somewhere, but I cannot find it.  What are the specs for a ball value to fit to the Racor and where did you pick up one?  I have been using needle-nose pliers and a short length of tubing to close off the fuel flow, but a valve would be an improvement.  Thanks for the help.

[Ron Hill]

Steve : As I recall all you need is a male 1/4" NPT thread to go into the RACOR and a barbed 3/8" male on the other side of the valve to go into the fuel line.  
Look on page 603 and 610 of the new 2010 West Marine catalog at the #33300-10 Moeller valve.  You might be able to find that kind of valve with those ends all in one somewhere else.  A thought

[Stephen Butler]

Many thanks Ron.  This will be one of the first modifications after the boat is off the hard in June..second only to replacing the plastic/nylon throttle and gear controls with metal ones.