changing to new filter system-air in line??

The friendliest place on the web for anyone who enjoys boating.
If you have answers, please help by responding to the unanswered posts.

Fighterpilot

Senior Member
Joined
Apr 17, 2011
Messages
380
I removed one tank and have replaced with another. At the same time I am converting from Racor 900s on both tanks to Seaboards duel fuel filter system. I plan to have fuel filters filled using the Seaboard primer pump system. Since it was reommended that the pump primer be in front of the filters I am assuming I can "push" fuel thru the crap filter and into the next filter until both are full. But when I cut the line that feeds the engines from the existing racors, so I can hook the line to the new filter system, I will proably get some air in that line. Than do I use the primer pump on the 3208NA main filter to pull fuel thru to clear the air. Do I take the engine filter off and pump, catching the fuel in a container until any air that got in the line has cleared, than screw the engine filter on and pump somemore till fuel runs down the sides of it? Thanks
 
I believe you will find a port on the head of the on engine filter that is intended to be loosened to bleed air.
Fill the new filters, connect the line, then use the engine primer to purge the reconnected line untill you get solid fuel at the loosened port. You shouldn't need to remove the on engine filter at all.
The primer bulb may also be able to push fuel through the total distance once the port has been loosened. I think though that I would first fill the new filters purging them first, then do the rest of the system. That way you don't have to purge the entire system in one go.
The engine should fire up once the on engine last filter is purged. Any tiny bits of air the engine should purge itself with some stumbling for a bit.
 
My cats had a bleed screw (regular t handle bleed with hole in the t) right on the injector pump that you opened and used the hand pumps on the filter bracket to prime to the injector pump bleed. After that, the engine self primed in severeal or less 1-5-20 second cranks.

Very easy with mine and they were the 320 hp 3208Ts of late 80's vintage.
 
Last edited:
tee handle??

Primer pump doesn't have any ports for bleeding. I do have the t handle on top of the injector pump. Really small, appears to be some sort of shut off maybe or does the t handle unscrew the fitting and lift out to open up the line? Should I put a small wrench on the nut base of the t handle to break it loose? I don't see where turning the t handle will open any port unless itself comes out of the top of the fitting or the whole fitting lifts out. Thanks
 
mine had a tube (and I don't recall exactly where it was attached) that drained low on the side of the engine.

so when I cracked the "t" on the injector pump and pumped (the one on the fuel filter housing), fuel would stream out of a small (around a 1/4 inch hose or so) hose and squirt into the bilge (till I learned where it was and could place a can there when bleeding).

here's a better written description...

on a 3208 fuel injection pump there is a check valve on the fuel return side that maintains fuel pressure in the system. this check valve should be overcome by the hand prime pump and not allow any overpressure of the fuel injector pump housing. Aprox 30PSI is when this valve opens. So not cracking a line as you have should not have failed the pump in any way.
There is an easier way to bleed the system, on top of the fuel injector pump housing there should be a small tee handle valve that is connected to one of three small plastic drain tubes. Opening this valve bypasses the check valve allowing for bleeding the fuel injector pump housing of air without building the 30 PSI and excess fuel runs through the tube and can be collected. The other two plastic tubes are telltail tubes that when fuel runs from them indicate a leak of fuel into areas not designed to have fuel in them.
 
Last edited:
Ahhh, so. Will have to see where the small hose empties and get a wrench to loosen the t handle base and try pumping. Going to hook the tank up this afternoon and see if I can get the engine on line. Thanks.
 
Ahhh, so. Will have to see where the small hose empties and get a wrench to loosen the t handle base and try pumping. Going to hook the tank up this afternoon and see if I can get the engine on line. Thanks.

Don't loosen the base unless u just can't get that T-handle to turn...it may be wrench tight...but it should move as the innards are lubed by diesel.
 
Update--new fuel tank installed, new Seaboard fuel filter system installed for both tanks replacing the Racor 900s, Gen. changed to the larger of the tanks, and all hoses back to their original configuration (Genny an exception), and all engines started and stayed running--thanks to the forum contributions.

I'm getting there. Heat exchangers cleaned, new zincs, oil changed, new filters, new on engine fuel filters, one tx. oil changed and checked for slippage, Riser raw water holes cleaned out, batteries replaced with lighter batteries, Two gps/fish finders added plus transducers, and trim tab hpu being reworked.

Yet to do--check out winch/anchor system, cut an install sounddown carpet underlayment and carpet, and get letters for the boat's new home port--Bagdad, Fl, home to the Masters Golf Tournament winner this year as well. Just had to throw that in. Thanks for all your help. FP
 
Sometime you may run out of fuel, or forget to switch tanks on time.

NOW is the time to plan for this hassle.

My advice is the DD hand pump on a past post. About$75.

With the correct fittings aboard it will only be 5 min in the HELL HOLE to restart..

FF
 
Sometime you may run out of fuel, or forget to switch tanks on time.

NOW is the time to plan for this hassle.

My advice is the DD hand pump on a past post. About$75.

With the correct fittings aboard it will only be 5 min in the HELL HOLE to restart..

FF

He mentioned a primer pump and I'm guessing it's the same filter housing primer pump most of those CATs had from that era. They work great for most people...you just gotta know about the bleed valve on top of the injection pump housing.
 
Yes, I found the T handle valve mentioned in the forum and used it to open the line and using the on filter housing primer pump gave it a few pumps. With the bulb primer on the filters and the filter housing pump I should be able to survive. Thanks for the advice.
 
The pump I suggested , and carry, is used to suck air from the final filter , to purge a system or at times it is used to pressurize (will do over 50psi) a fuel line from a tank to find an air leak.

A tiny air leak is easy to find , even at 5 psi!

Also will check , check valves , and of course DD owners use it to find leaking jumper struts..

It has solved many questions on a large variety of boats , with a handful of fittings.

FF
 
Back
Top Bottom