Lehman 120 dual type fuel filter

I have a Lehman 120 with about 7000 hours on it. It stalls after running for about 2 hours. I have replaced the fuel lines, the primary and secondary filters, and the lift pump. I believe it is all being caused by the bleed screw and the securing bolt weeping on the first of the 2 secondary filters. I have replaced the copper washers but there is still evidence of diesel after the motor has been running. I am thinking of replacing the entire (Simms) filter with either a new one or a suitable replacement.
I wonder if there are new ones available for sale - couldn't find any on the net, or if there are replacement ones that have the same bolt pattern and line attachment points that are recommended.
I am using a 2 micron filter in the primary filter (Racor) and 2 micron filters in the secondary unit. Is this the best setup or should I change to a 10 micron filter in the primary?

KDA,I recall, from old threads a replacement exists. Intended to make changing the on-engine filters easier by a different retaining system. Maybe you can search it out,here or online, or someone has one. I think long departed member Marin installed one(two probably). Or ask Brian at American Diesel Corp.

KDA, this might get you started,I see the field was ploughed quite recently.

http://www.trawlerforum.com/forums/s6/cav-conversion-parts-firefly-34808.html
There has been plenty of discussion of microns and how filtering levels should progress. I say the on engine filters should be finer/less microns than the primary. But I`ve never discovered the micron rating for the on engine CAV (or Delphi) type.

Or just hang a completely different type of modern filter on there.

I used a Racor 120 that has worked flawlessgly and easy to repkace or bleed.

My only mistake was getting the one with the plastic bottom.

While I like it the surveyors/insurers of the world will probably insist on a fire shield.

Moved thread from "How To Use The Forum, Site News & Account Concerns" to "Power Systems".

The manufacturers of the CAV filters don’t list the micron ratings that I have ever seen. Spoke to one and they said they are about 5 to 7 microns. Don’t know if that is real or not since it was not in writing. If I was having problems and was going to replace the CAV style and did not have SP225s, I would probably go with the spin on adapter. Brian told me that they do not fit on the 225s.

Gentlemen, thank you for your replies. I'm still not sure if there is a replacement filter available or if I should just install one on the bulkhead and forget about the one on the engine. Seems to me that the feeling is that CAV filters are not my best bet.
Anyway, I appreciate your insight and suggestions.

The duplex filter and injection pump are on the discharge side (pressure) of the lift pump.

I doubt that is causing your stalling problem. Most likely air leaking in somewhere between the lift pump and the fuel tanks. Go over that section of fuel line with a white paper towel. ANY fuel leaking out will leak air IN when the engine is running. That will stall your engine just as easily as a line blockage.
BTW, when the engine stalls, what does it take to get it running again? Bleeding, changing filter elements?

KDA said:

Gentlemen, thank you for your replies. I'm still not sure if there is a replacement filter available or if I should just install one on the bulkhead and forget about the one on the engine. Seems to me that the feeling is that CAV filters are not my best bet.
Anyway, I appreciate your insight and suggestions.

Click to expand...

It is easy to fashion a small adapter plate to accomodate almost any suitable filter.

But Archie (HighWire) brings up a good point about being on the pressure side.

Don't ignore the possibility that your tank pick-up could be blocked. Blow some air through the lines, and treat or polish the fuel if there is a lot of crap in the tank (happened to me).

Also, IMO a 2 micron primary with suspect fuel will drive you to drink and bankruptcy changing filters with dirty fuel. Up the micron number for the primary. The on-engine filters will handle the rest at 2 microns.

This all assuming you have no air leaks...

I tossed my Simms and remote-mounted a Racor 500 with nice new fuel hoses. Remote mounted for vibration.

I had the same problem, air leak on my Simms pump and it was a tiny screw that needed a new copper washer. Or anneal the old one if you can’t find a new one.

Definitely an air leak.

KDA said:

.... I'm still not sure if there is a replacement filter available or if I should just install one on the bulkhead and forget about the one on the engine. Seems to me that the feeling is that CAV filters are not my best bet.
.

Click to expand...

There is a replacement,somewhere on TF there are pics of it.
You should already have a filter on the bulkhead, getting most of any gunk before it gets to the on engine twin set up. If not, investigate Racors, it need not be a big Racor, Lehmans don`t filter and return much more than they burn.
My previous boat with a Perkins T6354 had a single CAV on a bulkhead, plus the on engine pair. Nothing wrong with CAV type filters,though I`d say Racors are better, but their disposable filters cost far more.

I think you guys are on the right track. High Wire makes a very good point that I hadn't considered. the air leak has to be coming into the system on the vacuum side - upstream of the lift pump. I will go over the system again with the suggested white paper towel. FYI, I have been quoted just shy of $500 Cdn for a new Simms dual fuel filter. I think I will look at a new secondary - maybe a Racor - mounted on the bulkhead and turf the old one. Thanks again everyone who took the time to hear my problem and respond

Use an outboard tank with a fuel bulb to pressurize your fuel system from the tank pickup onward.

Tear up paper towel into strips and place one at every joint or fitting.

The leak will be Ez to find.

The on-engine fuel pump has a handle you can manually pump to pressurize the system.

Just take out each small screw one at a time and replace the copper washer.

Call American Diesel in Kilmarnock, VA. When it comes to Lehmans, there is no one better to talk to. Chances are he has heard your exact problem a couple dozen times and knows what you need to do.

If they tell you your "flux capacitor" needs to be replaced...don't hesitate, just buy it.