FL SP225 lift pump problem

[BobH]

Changed the engine mounted fuel filters today. Port engine was able to bleed filters using the pump plunger. Was also able to pump through the lift pump with an external pump which I use to fill and purge the Racors. There was some leakage around the plunger. I assume you unscrew the plunger to use it. On the starboard engine the plunger does not feel like it is pumping and there is a lot of leakage around the plunger. I was not able to pump through the lift pump with my external pump. Can’t seem to get the filters purged.


Any thoughts,

Bob Horn

 

[ben2go]

I'm sure someone will come along with a response to the specifics of your problem.When I used to operate diesel powered equipment,we hardly ever used the primer plungers.Instead,we did it the old fashion way.Fill the fuel filters,crack open the injector lines at the injectors,turn the engine over,and tighten the injector lines as fuel started to trickle out of them.Sometimes the engine would spring to life.Other times we had to retry.It normally worked unless their was an underlying IP problem.

 

[BobH]

I think I figured out the problem. The new filters are a different brand and I think I installed the gaskets incorrectly. Not sure yet why it seems to be working on the port engine. Will investigate shortly. Still concerned about the leakage from the plunger on the lift pumps.

More later,

Bob

 

[BobH]

Got the gaskets figured out. Still unable to fill and purge the filters on the starboard engine with the lift pump plunger pump. Took out the bleed screws and filled the filters through the bleed plugs. Engines back up and running.

Bob

 

[C lectric]

Maybe the plunger pump needs a new set of seals. If there is enough leakage then the little pump cannot build any pressure and fuel is just bypassing the plunger, moving back and forth inside. Sounds like what is happening.

 

[BobH]

I've been in touch with Bomac and they say there is no rebuild kit. I'm concerned that if the manual part of the pump is that bad what shape is the rest of the pump in?

Bob

 

[Adelaide]

I've been in touch with Bomac and they say there is no rebuild kit. I'm concerned that if the manual part of the pump is that bad what shape is the rest of the pump in?

Bob

Bob,

I just went through this myself with my FL80. Next time your pump doesn't seem to to be getting any pressure, turn your engine over (Don't start it). You might have to do it twice to get it perfectly aligned. Only the high filter bleed screw needs to be open to properly bleed the air out of the filters. My local diesel mechanic showed me this. Well worth the 80 bucks to have him go through all this with me.

He also showed the gasket goes into the top of the housing NOT inside the top of the filter. Also, one gasket is a little larger than the other, the larger one goes on the top. Good luck!

 

[C lectric]

{{{turn your engine over (Don't start it).}}}}

Should have thought of that. The lift pump may be run off the camshaft by a specific lobe, common on many engines. If the lobe is at full lift then the manual plunger has no movement left. Cranking the engine over will move the lobe, hopefully, to fully relaxed allowing the manual plunger its full range of movement.

 

[BobH]

I cranked the engine several times and the result was the same. The plunger moves and a lot of fuel keaks out around the plunger.

It took me a while but I did figure out the position of the gaskets.Not sure why there is an extra one.

Bob