Bleed water/fuel separator first or engine filter first?

[redbeard1]

Hello all,

We have a 1993 Pacific Seacraft with 2003B Volvo Penta engine we purchased last fall. The fuel flow is: fuel tank, Racor 220 series water/fuel separator, Bellow electric priming pump, Volvo engine fuel pump, and Volvo engine fuel filter. We are going to change the filters on the water/fuel separator and the Volvo engine fuel filter.

The operator manual for the water/fuel separator tells us to bleed air from system using the priming pump.

The operator manual for the Volvo engine fuel filter tells us to bleed air from the system using the manual lever on the Volvo engine fuel pump.

I’m wondering if I should bleed the Racor water/fuel separator first or the Volvo engine fuel filter first? Does it matter?

 

[907Juice]

Not knowing anything about your engine, Id work from the tank to/through the engine. Doesn't do any good to start in the middle. So in my mind the racor first. May as well bleed the lift pump on your way through also.

Juice

Hello all,

We have a 1993 Pacific Seacraft with 2003B Volvo Penta engine we purchased last fall. The fuel flow is: fuel tank, Racor 220 series water/fuel separator, Bellow electric priming pump, Volvo engine fuel pump, and Volvo engine fuel filter. We are going to change the filters on the water/fuel separator and the Volvo engine fuel filter.

The operator manual for the water/fuel separator tells us to bleed air from system using the priming pump.

The operator manual for the Volvo engine fuel filter tells us to bleed air from the system using the manual lever on the Volvo engine fuel pump.

I’m wondering if I should bleed the Racor water/fuel separator first or the Volvo engine fuel filter first? Does it matter?

 

[Christian Williams]

Fill the new Racor filter with fuel before installing. Turn on the electric priming pump for a minute or two and then see if the engine starts.

If it doesn't, manual bleed the Volvo way.

The little hand pump on the Racor 200s was put there by the devil. It takes more than 100 awkward strokes to fill the filter. So install it filled.

It can be hard to get the old filter off. Band wrench. New one will be slippery. Band wrench ("hand tight" insufficient).

 

[Loren Beach]

Not sure, but that Volvo engine may have a manual small lever-operated pump that is supposed to be used to move minuscule amounts of diesel thru, per stoke, when purging the system. (The Deere 150 hp on our club's former dredge had this. Frustrating way to fill the lines and filters...)
By comparison, the Universal diesels in the Ericson's and Olson's have an electric lift pump, which makes bleeding the fuel system of air a lot easier.
So, same idea, but different way to doing it.

 

[redbeard1]

Sorry for late reply, just got back from boat.

Thanks to all for the replies. Christian, thanks for your post of 10-05-2015, 11:22 AM. I used the link you cited to get lots of useful tips for the entire process. I had decided to bleed back to front like Juice suggested. Loren, you are right. The fuel pump on the engine has a small lever that is meant to be used to bleed air from the fuel filter on the engine.

Unfortunately, it seems one of our two fuel pumps is broken. We had a mechanic adjusting valves on the boat today and he mentioned he thought the fuel pump on the engine (the one with the manual priming arm) is broken. There is no resistance when toggling the arm up and down. He thinks our bellows electric pump has been doing all the pumping (i.e., the bellows priming pump is being used to move all the fuel through the system).

My original question seems irrelevant at this point. I will do more research this week, but in the meantime if anyone can answer any of the following, thank you.

1) How can I tell if the fuel pump on the engine is truly broken? The manual lever moves with no resistance at all. This lever is only meant to be used for priming the filter that is immediately downstream. Could it be that only the priming part of the pump is broken?

2) Is it safe to operate the boat with just one fuel pump? I imagine many boats don’t have the priming pump, so I imagine this is safe but just wanted confirmation.

3) Can I prime the entire fuel system with just the electric priming pump? The Racor manual says that the priming pump is not meant to bleed the entire system, only the Racor water/fuel separator. I imagine that this is because electric pumps put out lots of pressure downstream (second fuel filter is downstream of this pump). If this is the only reason, we can just lay out lots of towels to catch the spurt of fuel. If there is another reason, I’d like to know.

As a reminder our fuel flow is: [fuel tank] to hose to [Racor 220 series water/fuel separator] to hose to [Bellow electric priming pump] to hose to [Volvo engine fuel pump with a manual lever which lever is used to prime the Volvo engine fuel filter (assume this pump is broken)] to metal tube to [Volvo engine fuel filter] to metal tube to [fuel injection pumps], etc.

Thanks to all in advance. In spite of the mechanic’s possible bad news, weather was wonderful as we put finishing touches on our boat. Hope all had a great day.

 

[907Juice]

Sorry for late reply, just got back from boat.

Thanks to all for the replies. Christian, thanks for your post of 10-05-2015, 11:22 AM. I used the link you cited to get lots of useful tips for the entire process. I had decided to bleed back to front like Juice suggested. Loren, you are right. The fuel pump on the engine has a small lever that is meant to be used to bleed air from the fuel filter on the engine.

Unfortunately, it seems one of our two fuel pumps is broken. We had a mechanic adjusting valves on the boat today and he mentioned he thought the fuel pump on the engine (the one with the manual priming arm) is broken. There is no resistance when toggling the arm up and down. He thinks our bellows electric pump has been doing all the pumping (i.e., the bellows priming pump is being used to move all the fuel through the system).

My original question seems irrelevant at this point. I will do more research this week, but in the meantime if anyone can answer any of the following, thank you.

1) How can I tell if the fuel pump on the engine is truly broken? The manual lever moves with no resistance at all. This lever is only meant to be used for priming the filter that is immediately downstream. Could it be that only the priming part of the pump is broken?

2) Is it safe to operate the boat with just one fuel pump? I imagine many boats don’t have the priming pump, so I imagine this is safe but just wanted confirmation.

3) Can I prime the entire fuel system with just the electric priming pump? The Racor manual says that the priming pump is not meant to bleed the entire system, only the Racor water/fuel separator. I imagine that this is because electric pumps put out lots of pressure downstream (second fuel filter is downstream of this pump). If this is the only reason, we can just lay out lots of towels to catch the spurt of fuel. If there is another reason, I’d like to know.

As a reminder our fuel flow is: [fuel tank] to hose to [Racor 220 series water/fuel separator] to hose to [Bellow electric priming pump] to hose to [Volvo engine fuel pump with a manual lever which lever is used to prime the Volvo engine fuel filter (assume this pump is broken)] to metal tube to [Volvo engine fuel filter] to metal tube to [fuel injection pumps], etc.

Thanks to all in advance. In spite of the mechanic’s possible bad news, weather was wonderful as we put finishing touches on our boat. Hope all had a great day.

Like I said earlier, my disclaimer is I have a small yanmar engine. I don't have an electric pump but the mechanical pump on the side of the engine is my primary pump for the non-pressurized side. Last year it went out and I was having all kinds of fuel problems. In addition if that diaphragm goes bad you can leak fuel into the oil and cause an engine overrun. I'd just replace it. Also you can only manually bleed to the fuel injector and pressurized side. After that you need to use the engine.

YouTube is your friend here. Lots of good videos there. Couldn't find your specific engine but found this one which shows the process in a clean and neat fashion. . https://youtu.be/5ON8ZxkRxkA

 

[redbeard1]

Much obliged. Thanks to the replies here and other research, I've got a plan for my debugging trip to the boat this weekend. I'll let you all know how it works out.

 

[erikwfab]

Fuel System Priming

I have a 30YM Yanmar 27HP and a single element Racor. What i installed in the fuel line before the Racor was a simple outboard motor fuel line bulb. The kind everyone has squeezed before starting your Evinrude, Mercury, gas outboard engine.
it provides a simple way to prime the filter after changing and then after the top is back on the Racor you can create fuel psi to the engine. Its rated for gas, 1/4" inline installation is simple and works great.