Secondary Fuel Filter on1981 H 30

[Nelsonhow]

Well,

It's getting there... I'm changing the fuel filters on the 2 GM. The primary (on the motor) is no problem but on the wall of the engine compartment is a bronze colored secondary fuel filter about 3 1/2 inches roung and about 6 inches high that has the marking LST(O?) 7158 Marine Filter on it. The fuel line from the tank goes in one side and the other goets to the primary fuel filter on the engine so I'm sure it's a fuel filter. The name and number are casted into the case and a little hard to read.

I looks like the top of the unit screws off (not sure) as there is a little rectangular nub like for a wrench on the top. It did not yeld to some moderate tirning effort with a vice grip. The bottom has what looks like a small bowl with a screw on the bottom.

Does anyone out there in hunter land have any suggestions on how to service this filter? Is this a fuel filter and water seperator ? Dose the top screw off to change the element?
Any idea of the element (if there is one) brand and number?

Any help would be appreciated....

H- Nelson

 

[Don S/V ILLusion]

Nelson
What you describe sounds like an old Mariner filter housing you might think about replacing with a contemporary model as I'm not sure you'll easily find filter element replacements.
To dissemble, remove top nut. Housing sound drop down. If the filter is lower then the tank, it will gravity flow forever until you shut off the tank supply valve so do that FIRST.
In addition to the suggestion I made to replace the whole thing, having a new one with a clear bowl at the bottom allows much easier inspection for water and contaminants in the future.
After you are done, you will have to bleed the low pressure side regardless of whether you just replace the filter element or the whole thing.
By the way, no big deal but you are transposing terminology - the primary is the first filter closest to the tank.

 

[Steve Dion]

Nelson: I am with Don. I suggest that you get a high quality like a Racor and replace that "Primary" filter.

 

[Benny]

It is both a fuel filter and a water separator. The screw on the bottom is for draining water and the top will screw off to reveal a porous composite filter that can be washed and reused. Other than draining water maintenance is minimal, just clean it every six months or as needed. If you are going to remove the casing for cleaning make sure you shut off the fuel tank petcock. When removing the bottom screw lay down a towel so you can catch it in the likelyhood you may drop it. In your setup this is your primary filter with the secondary filter being on the engine to filter the small stuff. If your set up is working fine I would not recommend upgrading to a modern filter as sometimes such upgrades bring additional maintanence requirements and unexpected problems. The modern filters come with disposable cartridges and although they are not very costly you have to go out and get them and it is another thing to worry about. If you are having heavy condensation problems or a tank dirty with sediments an upgrade would be in order but if not get another 20 years use out of that one.

 

[Nelsonhow]

Benny,
I think, since the element can be cleaned, that I'll stick to the current system, at least for now. I've turned to fuel valve off. The top of the filter unit looks like it's casted and screws into the casted bottom. I don't know when it's was off last but it didn't move with a plier on it but I have to admit the position is rather akward behind the motor on the left. Any trick to getting it off that you recommend would be appreciated.

Howard

 

[Benny]

It is just tight; get some leverage by using a 10 or 12 inch adjustable wrench for the top and a pair of channel pliers to hold the body. Worst case scenerario remove fuel lines and remove the two screws holding the filter and work on it on a bench vise.

 

[reserche]

new primary filter

I've just gone through this filter issue - I'm having a new racor installed, so the motor filter becomes a secondary. This was recommended by both an experienced Captain and my marine mechanic. Best of luck....

 

[Nelsonhow]

Thanks to all... it turns out that the old style filter is made by PERKO and they still have the elements with the o ring in stock, I ordered a replacement. But they are cleanable. Mine had not been changeds in so long that the top was stuck. I realized that the filter body was mounted in a holder and secured in place with one in small set screw. Took the set screw out and disconnected the hoses and put the filter body came right out . Took it to the work bench vice and it came apart with little effort. Maybe next year I'll switch it out. For now, the element wasn't that dirty but it cleaned it out with gasoline and then diesel fuel and it's fine for now. Thanks again for all your adivce.