My Westerbeke is Sucking Air - Help!

[skipmac]

Help. I can't keep fuel going into my Westerbeke.

Just bought the boat (and thinking about resurrecting the thread about POs and what they did). Assumed the fuel was old so ran it enough to get home and planned to deal with it asap. But before I could the engine starting choking down so shut off and changed both filters, primary Racor water sep (was full of crap) and the secondary on the engine. Filled both filters, bled a little and cranked up. Engine ran for about 2 mins and stopped. Checked and both filters were dry. Took fuel lines apart and blew backwards into the tank and got bubbling. Put system back together, refilled filters, bled a little more, cranked, same results. Checked lines for leaks, found one that was cracked on the end, cut back to good rubber and replaced (yes I plan to replace the whole thing as soon as I can get to the store to get more fuel line).

I've repeated this several times and every time both filters are emptied. The Racor is only empty in the top housing, the glass bowl stays full. I have cleared the line from the Racor all the way back to the tank and also checked the vent.

Any ideas what to try next?

[Chief Engineer]

Start at the tank and work towards the engine

Make sure that ALL the Gaskets/O-Rings are in the Racor

Make sure the fuel ines on the racor are in te proper position...there is only one way to hook it up....The Filter assembly has an "in" and "out"

[skipmac]

Three gaskets in the Racor?

1. O-ring on shaft of T-handle
2. Large O-ring under the metal top
3. O-ring between glass bowl and metal body.

Checked 1 and 2 and replaced both. If 3 was out or leaking would that be why the top of the Racor is empy and the bottom glass bowl stays full?

The lines are right, they are cut, run and tie wrapped so they can't be swapped.

Went to the tank and checked pickup, return line and vent line. Blew clearly into the pickup at the tank and got bubbles. Put pickup line back on and blew from tank selector valve (two tanks but I'm only working on one) and got bubbles again into the tank. Blew from selector line out on the valve into the Racor and got clear.

[skipmac]

Thought back and recalled that I did not remove the glass bowl on the Racor so if there is an O-ring there it wasn't disturbed.

[S/V Antares]

Check that the pick up in the tank is clear by blowing back through. Could be a lot of do do in the tank. Got a cleanout? If really have a bad fuel problem run it off a 5gal jug till you get back to where you can really work. . Be sure to route the return back to the jug.

There is a little alumimum ball in the racor just above the bowl. Make sure it is not stuck with crap from the tank.

[John A]

Bypass the Racor to verify that it's a problem with the filter. If it is then I would bet that someone completly disassembled the Racor filter and then reassembled it wrong. I can't remember which way it goes but the steel ball needs to be in its proper position to allow the fuel to enter from the tank.

A cone shaped part just above the glass bowl can also clog up and restrict the fuel flow.

[mesquaukee]

How's the lift pump.
It sounds as if the injection pump just uses the little bit of oil in the top of the filter. The lift pump is supposed to keep it full. It isn't.
How do you prime your lines and filters?
On your westerbeke is the lift pump that ancient little electric vibrator thing or is it a mechanical pump? If it's the vibrater pump check the wiring.

[Boracay]

Is it an old Racor filter?

[skipmac]

Antares

- Have blown forward and backward from the tank vent, tank, tank valve to the Racor. Lines are clear and I'll be tasting diesel for the next month.

- How do you check the ball valve? Pull the bowl? If I can pour diesel in the top and it fills the bowl does that verify the ball valve is working or does it work for fuel going out of the bowl?

John A

Racor was only disassembled by yours truly as so: Top off, old filter element out, new in. Bottom drain off, drain fuel into jug, replace bottom drain, fill with fuel from top.

System has been working for years until I changed the filters, so as much as I hate to admit it, it must be something I did.

mesquaukee

Is the lift pump the cylinder about 6-7" high, 2" diameter between the Racor and the secondary filter on the block? Has a couple of wires going to it and it makes noise when I turn on the ignition switch. If yes, then since the Racor is before the pump and it is sucked dry then it isn't the pump.


Thanks everyone. The suggestions are greatly appreciated. Now I'm going back in and try some more.

[skipmac]

Went back and saw a small drip coming off the bottom of the Racor. Looked closer and the o-ring around the drain on the bottom of the Racor was broken.

Maybe that is it? Any comments?

[Chief Engineer]

Seems that you have found the problem.

All you need is a small leak...it can introduce "tiny bubbles" (sorry Don Ho) almost like champgne....they accumulate and poof no fuely-fuely.

Another thing I have seen is a cracked fuel pickup....when the fuel gets low....the air comes in......you will still hear bubbling when you blow into the tank

[John A]

Rule # 1 if fuel can leak out then air can leak in.

Check that cone shaped part for any blockage while you're tinkering with the bottom end of the filter.

[mesquaukee]

I would suggest you reinstall the racor after the fuel pump. Yes it is that noisy thing with the wires.
Install a switch on it or use the ignition switch and you can use it to fill the racor.
You will never have an air leakage problem again with your racor if a seal isn't quite right. Instead you will have a fuel leak which you will notice when you first start up the engine.
Set up this way if you had to quickley change a filter at sea (a sloppy sea stirs up the dirt in the tank) and if it leaks who cares, at least you will not end up on a reef.

On some boats with the fuel tank built into the keel that vibratory pump might have trouble picking up fuel when you have messed with the filters. If this is the case you can plumb in a squeeze bulb at the top of the tank to help it start up quick.

[skipmac]

Chief Engineer

You might have hit the problem on your first post. Am focusing on the o-ring on the drain. Found a regular round rubber o-ring in the POs spares but the old one on the Racor was a flat ring, more like a fat washer than an o-ring. Not sure if the spare i found was the right part even though it fit.

Do not suspect a cracked pickup since everything was working fine (except for dirity diesel) before I changed filters.

John A

Rule #1 - Amen to that. Since it seems I will have the #$#!@$/!!! thing apart yet again I'll look at the cone in the bowl. Definitely had some serious crude in the system.

mesquaukee

Thanks for two good suggestions. I was thinking about moving the Racor anyway since it is a far, barely accessable corner of the engine space. It would be pretty easy to put it behind the pump when I do so. A really hot system is to have dual, parallel filters and just switch to the second if you're in a tight spot and need motor fast. I like the squeeze bulb thing too. Not sure if having an empty line back to the fuel tank is exacerbating the problem but if I could fill the lines it would eliminate that question.


Again thanks to all. I finally gave up and called it a day. Took the dinghy to town, went to a nice Italian restaurant and had two gin and tonics. After all day soaked in diesel I figured I earned it.

[mesquaukee]

Dual filters are a good thing.
When you set it up have the outlet line of each filter go up into a loop. At the top of the loop install a tee with the leg facing up, put a valve on it. Then after this tee as the line goes back down install the isolation valve.
Then you can change a filter; bleed the air out of the line by opening the inlet isolation valve and cracking the valve at the top of the loop to let the air out.

I can swap a filter out in less than 5 minutes. I don’t use racors. I use giant sized truck filters, they are easier to swap out. They are available in any country and are inexpensive.
The bowl is larger and the filter surface area is much much larger. The boat I have has run for decades on them, no problems at all. I only change them and the fine filter on the engine every couple of years.
If you have a lot of blue mould in your tanks, which you should assume if you just bought the boat, they will not choke up in minutes as a racor will.
One boat I travelled with had to swap out his racor every 30 minutes in rolling seas.
The mould only breaks off the tank walls and gets sucked up when the fuel slops around.

Best Wishes, Tom