Releasing air lock via the first fuel filter

[pedroinlondon]

Hi

I need to fit a new tank, and by watching a few videos and talking to fellow boaters, I know that some important precautions need to be taken to avoid a massive air lock in the engine.

I will use the existing "fuel to engine" and "return to tank" hoses, and am under the impression that a good way to avoid the air lock issue would be to:

 

1. Isolate the fuel filter.

2. Fit the hoses to the new tank.

3. Undo a bit the bolt on the fuel filter that releases the air.

4. Turn the ingition (without starting the engine) to "suck the fuel" out of the new tank into the hoses (and filter).

5. Repeat the process until no air comes out.

6. Start the engine.

 

I learnt about steps 3. to 6. from the video below, which has a different type of filter, and it's a tutorial on how to release the air out after running out of fuel. That is not my case, so hopefully I won't need to continue the process on the injectors, only at the fuel pump.

 

 

Please let me know what you think about this. The relevant part starts at around the end of the first minute.

The attached photos are of the existing fuel filter in my engine.

The engine is a Lister Petter PW4A48, but I'm not sure that's relevant for this matter.

 

Many thanks!

 

 

Many thanks!

Edited April 27 by pedroinlondon

[Tony Brooks]

First of all Google does not recognise Lister Petter PW4A48, but returns hits for an LPWx where x is the number of cylinders. Google also shows LPW lift pump as mechanical, so turning the ignition on will do nothing to help bleeding.

 

I think that you need to clarify exactly what engine you have, you also need to clarify if you have a mechanical or electrical lift pump. If you don't know, then post photos of your engine showing both SIDES so we can identify the lift pump and advise.

 

Bleeding engines is not usually particular difficult, and those Lister engines seem to bleed  automatically, but I would not do that if the lift pump has a priming lever.

 

I think we await the clarifications.

 

[Alan de Enfield]

There is Lister range numbered LPA3, LPA4 etc I wonder if it is one of those.

 

My Lister manual covers the LPA3, LPA4 as well as the LPWS3, LPWs4 etc, LPWT3 ...........

 

I think it is probably an LPW4 A (rotation) and 48 (build), but having said that ..............

 

But - Could it be an LPA4 48 ?

 

With the '48' being the build specification ?

 

Engine Serial Number
The engine serial number is stamped on a plate
attached to the engine.
It is necessary to identify the type and build of each
engine to enable the correct maintenance procedures,
as described later in this publication, to be carried
out.
An example number is shown below.
03 00123 LPW3 A 01
03 ............ Year of manufacture code (03 = 2003)
00123 ...... Consecutive number of engine
LPW3 ...... Model
(T = turbocharger, S = indirect injection)
G = gas fuelled)
A .............. Anticlockwise rotation
01 ............ Build of engine

 

 

01.4.3 Marine Builds
Marine engines are designated Builds 40, 41, 42,
43, 44, 45, 46, 47, 48 and 49.
In general 'Alpha' marine propulsion engines are
designed for the following applications.
LPA - leisure and commercial craft.
LPW - workboats and commercial craft.
LPWT - workboats and commercial craft.
LPWS - canal boats.

 

Edited April 26 by Alan de Enfield

[pedroinlondon]

12 hours ago, Tony Brooks said:

First of all Google does not recognise Lister Petter PW4A48, but returns hits for an LPWx where x is the number of cylinders. Google also shows LPW lift pump as mechanical, so turning the ignition on will do nothing to help bleeding.

 

I think that you need to clarify exactly what engine you have, you also need to clarify if you have a mechanical or electrical lift pump. If you don't know, then post photos of your engine showing both SIDES so we can identify the lift pump and advise.

 

Bleeding engines is not usually particular difficult, and those Lister engines seem to bleed  automatically, but I would not do that if the lift pump has a priming lever.

 

I think we await the clarifications.

 

Good morning Tony

Here are the two photos I have. 

I can take more this afternoon when I return to the boat.

Thanks

On a separate thread, Peugeot 106 said:

It’s Lister Petter LPW 4 cylinder 40 bhp build 48 (marine build) built in 2007 also known as Canal Star or Alpha. All spares Manuals etc available from Richard at MES Midlands or Sleeman Hawker Dorset and others. Manuals and Parts List also available online FOC

11 hours ago, Alan de Enfield said:

There is Lister range numbered LPA3, LPA4 etc I wonder if it is one of those.

 

My Lister manual covers the LPA3, LPA4 as well as the LPWS3, LPWs4 etc, LPWT3 ...........

 

I think it is probably an LPW4 A (rotation) and 48 (build), but having said that ..............

 

But - Could it be an LPA4 48 ?

 

With the '48' being the build specification ?

 

Engine Serial Number
The engine serial number is stamped on a plate
attached to the engine.
It is necessary to identify the type and build of each
engine to enable the correct maintenance procedures,
as described later in this publication, to be carried
out.
An example number is shown below.
03 00123 LPW3 A 01
03 ............ Year of manufacture code (03 = 2003)
00123 ...... Consecutive number of engine
LPW3 ...... Model
(T = turbocharger, S = indirect injection)
G = gas fuelled)
A .............. Anticlockwise rotation
01 ............ Build of engine

 

 

01.4.3 Marine Builds
Marine engines are designated Builds 40, 41, 42,
43, 44, 45, 46, 47, 48 and 49.
In general 'Alpha' marine propulsion engines are
designed for the following applications.
LPA - leisure and commercial craft.
LPW - workboats and commercial craft.
LPWT - workboats and commercial craft.
LPWS - canal boats.

 

On a separate thread, Peugeot 106 said:

''It’s Lister Petter LPW 4 cylinder 40 bhp build 48 (marine build) built in 2007 also known as Canal Star or Alpha. All spares Manuals etc available from Richard at MES Midlands or Sleeman Hawker Dorset and others. Manuals and Parts List also available online FOC''

[Alan de Enfield]

So, as suggested, it is an LPW4 with left hand rotation (A) and build number 48.

 

I have PDF manuals, if you would like copies - just message me with your email address.

Edited April 27 by Alan de Enfield

[Tony Brooks]

The engine number says it is an LPW4

 

Google says the LPW3 fuel lift pump is NOT an electric one and has a priming lever, so as I said turning the ignition on will do nothing.

 

12 hours ago, pedroinlondon said:

"return to engine" hoses,

 

This is the wrong way round, it is return from the engine to the tank. This one does not need bleeding as such because any air in it will be pushed into the tank by fuel flow once the Engin is running, there it will simply disperse.

 

12 hours ago, pedroinlondon said:

3. Undo a bit the bolt on the fuel filter that releases the air.

 

This bit is correct, but to get it to make the fuel flow into the filter you need to pump the priming lever on the lift pump. If the lever feels as it it has a lot of slack an dnot much pumping action turn the engine by about one turn, because the slack means the internal pump lever is sitting on the back of the eccentric on the cam.

 

Once air free fuel flows out - prime for at least 30 seconds once you think all the air is out in case there is a bubble in the pipe work. Tighten the bolt.

 

On that engien if you then try to start it there is every chnace it will, it may well start and then shake about a bit whileany air that has got inot the high pressure injection system clears. If it stops spin on the the starter in 30 second bursts a few times.

 

On other engiens and this one if you want to, rather that trying to start it right away, after bleeding the filter you can loosen (about half to one turn) the big nuts on the injector pipes at the injector  end and spin on the starter. When fuel drips or spts from the loose unions tighten them and it should start.

 

 

 

 

 

 

 

 

Edited April 27 by Tony Brooks

[pedroinlondon]

4 hours ago, Alan de Enfield said:

So, as suggested, it is an LPW4 with left hand rotation (A) and build number 48.

 

I have PDF manuals, if you would like copies - just message me with your email address.

Thanks Alan!

4 hours ago, Tony Brooks said:

The engine number says it is an LPW4

 

Google says the LPW3 fuel lift pump is NOT an electric one and has a priming lever, so as I said turning the ignition on will do nothing.

 

 

This is the wrong way round, it is return from the engine to the tank. This one does not need bleeding as such because any air in it will be pushed into the tank by fuel flow once the Engin is running, there it will simply disperse.

 

Sorry Tony. I meant to write that but my mind slipped. I have edited it above.

 

 

 

 

 

 

 

 

 

4 hours ago, Tony Brooks said:

The engine number says it is an LPW4

 

Google says the LPW3 fuel lift pump is NOT an electric one and has a priming lever, so as I said turning the ignition on will do nothing.

 

 

This is the wrong way round, it is return from the engine to the tank. This one does not need bleeding as such because any air in it will be pushed into the tank by fuel flow once the Engin is running, there it will simply disperse.

 

 

This bit is correct, but to get it to make the fuel flow into the filter you need to pump the priming lever on the lift pump. If the lever feels as it it has a lot of slack an dnot much pumping action turn the engine by about one turn, because the slack means the internal pump lever is sitting on the back of the eccentric on the cam.

 

Once air free fuel flows out - prime for at least 30 seconds once you think all the air is out in case there is a bubble in the pipe work. Tighten the bolt.

 

On that engien if you then try to start it there is every chnace it will, it may well start and then shake about a bit whileany air that has got inot the high pressure injection system clears. If it stops spin on the the starter in 30 second bursts a few times.

 

On other engiens and this one if you want to, rather that trying to start it right away, after bleeding the filter you can loosen (about half to one turn) the big nuts on the injector pipes at the injector  end and spin on the starter. When fuel drips or spts from the loose unions tighten them and it should start.

 

 

Alan sent me the manual and drawings to the engine, so I'll try finding my way around it over this afternoon. I don't know where the priming lever on the lift pump or the injector bolts are, but I will surely know before the day is over. Hopefully... Maybe...

Thanks Tony!

 

4 hours ago, Tony Brooks said:

 

 

 

 

 

Ala

[Tony Brooks]

32 minutes ago, pedroinlondon said:

Alan sent me the manual and drawings to the engine, so I'll try finding my way around it over this afternoon. I don't know where the priming lever on the lift pump or the injector bolts are, but I will surely know before the day is over. Hopefully... Maybe...

Thanks Tony!

 

Large injector pipe union NUTS, not bolts.

 

Priming lever on pump marked X

 

 

[pedroinlondon]

Great.

I'll have to feel my way to it, if it's even lower than the fuel pump.

Access it terrible on these boats, but with that photo it should be ok.

 

Thanks a lot Tony

[Tony Brooks]

11 minutes ago, pedroinlondon said:

Great.

I'll have to feel my way to it, if it's even lower than the fuel pump.

Access it terrible on these boats, but with that photo it should be ok.

 

Thanks a lot Tony

 

It is part of the fuel lift pump and is pivoted below the wide part of the pump body.  It may be pivoted on just one side of the lever may be forked so both sides are fitted to the lower body section as per my photo. Other images showed a lever just on one side of the pump, but still within the area covered by the wide part, whichever it will tend to be hidden by the pump itself.

[pedroinlondon]

On 27/04/2024 at 08:27, Tony Brooks said:

The engine number says it is an LPW4

 

Google says the LPW3 fuel lift pump is NOT an electric one and has a priming lever, so as I said turning the ignition on will do nothing.

 

 

This is the wrong way round, it is return from the engine to the tank. This one does not need bleeding as such because any air in it will be pushed into the tank by fuel flow once the Engin is running, there it will simply disperse.

 

 

This bit is correct, but to get it to make the fuel flow into the filter you need to pump the priming lever on the lift pump. If the lever feels as it it has a lot of slack an dnot much pumping action turn the engine by about one turn, because the slack means the internal pump lever is sitting on the back of the eccentric on the cam.

 

Once air free fuel flows out - prime for at least 30 seconds once you think all the air is out in case there is a bubble in the pipe work. Tighten the bolt.

 

On that engien if you then try to start it there is every chnace it will, it may well start and then shake about a bit whileany air that has got inot the high pressure injection system clears. If it stops spin on the the starter in 30 second bursts a few times.

 

On other engiens and this one if you want to, rather that trying to start it right away, after bleeding the filter you can loosen (about half to one turn) the big nuts on the injector pipes at the injector  end and spin on the starter. When fuel drips or spts from the loose unions tighten them and it should start.

 

 

 

 

 

 

 

 

 

Good morning Tony
 

It took me much longer than I expected to fit the new tank hoses and find the right fittings locally, so I was only able to fill it with fuel and try your fix yesterday.
I'm extremely happy to report that it worked perfectly! I primed the pump for the lenght of time you suggested and the engine started and run as usual. Not even a hiccup of protest or surprise from Mr Lister Petter.

I cannot thank you enough, as I've been waiting for mechanics to attend for about 8 weeks, and they have all failed to appear...

 

The only think I noticed afterwards, which may have been happening before, is that there is a tiny stream of diesel dripping from the bolt junction. It's hardly noticeable, and I have tightened the bolt as far as it can be.

Is this fairly normal and acceptable, or would be worth fitting a suitable rubber penny washer in there?

 

Thanks again 

[Tony Brooks]

Certainly not rubber because diesel will dissolve some "rubbers". Usually a soft copper washer is used there, if you have an old one try heating it to red-hot (I use the gas stove) and quench in water. This will soften it.

 

Make sure there are no burs under the bolt head.

 

If copper does not work, try a Dowty washer, the rubber used inside these is oil resistant.

[pedroinlondon]

2 hours ago, Tony Brooks said:

Certainly not rubber because diesel will dissolve some "rubbers". Usually a soft copper washer is used there, if you have an old one try heating it to red-hot (I use the gas stove) and quench in water. This will soften it.

 

Make sure there are no burs under the bolt head.

 

If copper does not work, try a Dowty washer, the rubber used inside these is oil resistant.

Thanks!

[Tony Brooks]

If you need ned one Dowty washer can be hard to find from normal sources, I doubt many chandlers or the likes of Halfords stock them. So f you need one try hydraulic hose suppliers, plenty on google and at least one would be fairly local.

[Peugeot 106]

On 27/04/2024 at 08:27, Tony Brooks said:

The engine number says it is an LPW4

 

Google says the LPW3 fuel lift pump is NOT an electric one and has a priming lever, so as I said turning the ignition on will do nothing.

 

 

This is the wrong way round, it is return from the engine to the tank. This one does not need bleeding as such because any air in it will be pushed into the tank by fuel flow once the Engin is running, there it will simply disperse.

 

 

This bit is correct, but to get it to make the fuel flow into the filter you need to pump the priming lever on the lift pump. If the lever feels as it it has a lot of slack an dnot much pumping action turn the engine by about one turn, because the slack means the internal pump lever is sitting on the back of the eccentric on the cam.

 

Once air free fuel flows out - prime for at least 30 seconds once you think all the air is out in case there is a bubble in the pipe work. Tighten the bolt.

 

On that engien if you then try to start it there is every chnace it will, it may well start and then shake about a bit whileany air that has got inot the high pressure injection system clears. If it stops spin on the the starter in 30 second bursts a few times.

 

On other engiens and this one if you want to, rather that trying to start it right away, after bleeding the filter you can loosen (about half to one turn) the big nuts on the injector pipes at the injector  end and spin on the starter. When fuel drips or spts from the loose unions tighten them and it should start.

 

 

 

 

 

 

 

 

Spot on!

[blackrose]

On my Isuzu I can take my fuel filters off and change them without any need to bleed the air out of the fuel system once I refit them. It's a self- bleeding system so you just turn the ignition and wait until the fuel goes through.

 

I've no idea how it works but when I read about people or see neighbours having to bleed their fuel systems it makes me wonder why all modern marine diesel engines don't have this self-bleeding feature? Is there any disadvantage?

[Tony Brooks]

20 minutes ago, blackrose said:

On my Isuzu I can take my fuel filters off and change them without any need to bleed the air out of the fuel system once I refit them. It's a self- bleeding system so you just turn the ignition and wait until the fuel goes through.

 

I've no idea how it works but when I read about people or see neighbours having to bleed their fuel systems it makes me wonder why all modern marine diesel engines don't have this self-bleeding feature? Is there any disadvantage?

 

Yes, you have an electric lift pump which requires electricity, whereas diesels used for some industrial applications may not be equipped with any electricity so they use a mechanical pump. Also, if the engine battery charging failed, eventually an engine with an electrical pump would just stop with no fuel delivery. It am sure it is difficult to understand here in the UK what such applications might be, but think third world where they push starts trucks so don't need electricity, or hand start diesels running pumps, crop driers and such like in jungle clearings.

 

As long as the OP's start battery is well charged and has decent capacity, I am sure his engine will self bleed by spinning the starter, as would Betas.

 

The filter and low pressure part of the injector pump self bleeds by using a greater leak back flow to the tank, so any air is carried back to the tank. However, I have not yet understood how the high pressure side bleeds, unless it is by spinning over for long enough to compress any air in the injectors pump elements and pipes to a pressure sufficient to allow it out of the injector.

 

Fitting an electric lift pump with plenty of spare capacity and modifying the pipework for the leak back system would probably make any modern engine with a mechanical lift pump self bleed.

[blackrose]

Ok I see. Thanks for the explanation. I'm still not quite sure why any firm marinising a modern engine for canal boat use wouldn't fit an electric lift pump and make it self bleeding? I'm not sure which brands they are but some clearly don't judging by some of the posts I read talking about bleeding the fuel system.

Edited April 30 by blackrose

[Peugeot 106]

29 minutes ago, blackrose said:

On my Isuzu I can take my fuel filters off and change them without any need to bleed the air out of the fuel system once I refit them. It's a self- bleeding system so you just turn the ignition and wait until the fuel goes through.

 

I've no idea how it works but when I read about people or see neighbours having to bleed their fuel systems it makes me wonder why all modern marine diesel engines don't have this self-bleeding feature? Is there any disadvantage?

LPWs are also usually self bleeding if you have enough battery to turn the engine for long enough. The air just gets pushed into the tank through the spill line . But I have a feeling that air in the injectors can cause difficulties as air is non compressible though it’s never happened to me in which case it’s easy enough to turn the injector joint nut so you know you’ve got diesel up to that point

[Tony Brooks]

8 minutes ago, blackrose said:

Ok I see. Thanks for the explanation. I'm still not quite sure why any firm marinising a modern engine for canal boat use wouldn't fit an electric lift pump and make it self bleeding? I'm not sure which brands they are but some clearly don't judging by some of the posts I read talking about bleeding the fuel system.

 

I think it is a money thing. To change from the mechanical pump fitted by the engine manufacture, the mariniser would have to take the mechanical pump off and make & fit a blanking plate. If the mechanical pump was left in place in later years, it could cause oil leaks or if the fuel still flowed through the mechanical pump fuel could end up in the sump.

 

Then, if the leak back system was not suitable, that would have to be re-piped.

 

Then they have to dispose of the mechanical lift pumps and anything else they changed.

 

To be honest, bleeding most fuel systems is not difficult, especially with vertically mounted spin on filters that you can fill before fitting. The problem is many boaters seem to think it is difficult or like to talk it up. perhaps the biggest problem is that people won't keep priming for long enough, so all the air bubbles are not purged.

3 minutes ago, Peugeot 106 said:

LPWs are also usually self bleeding if you have enough battery to turn the engine for long enough. The air just gets pushed into the tank through the spill line . But I have a feeling that air in the injectors can cause difficulties as air is non compressible though it’s never happened to me in which case it’s easy enough to turn the injector joint nut so you know you’ve got diesel up to that point

 

Not technically true. it is fuel that is all but non-compressible, air is compressible, so the injector pump has problems increasing the pressure in the injector pipes enough to lift the injector needle.

 

As you say, not difficult to allow for.

[Peugeot 106]

That’s what I meant I got it the wrong way round. I’ve pressure tested plenty of pumps! When I started I wasted ages thinking I wasn’t bleeding properly but the return pipe had been incorrectly plumbed back to the filter. Once that was corrected and I ran it to the tank I never had any more problems

[Alan de Enfield]

2 hours ago, Peugeot 106 said:

 air is non compressible

 

I beg to differ - we tend to get 'compressed air' in our car tyres, and I certainly get compressed air (230 atmospheres) in my diving cylinders. The air is so compressed it has a consitency almost like Nutela.

[Peugeot 106]

14 hours ago, Alan de Enfield said:

 

I beg to differ - we tend to get 'compressed air' in our car tyres, and I certainly get compressed air (230 atmospheres) in my diving cylinders. The air is so compressed it has a consitency almost like Nutela.

Yes I know see above! Dyslexia ok rules

[ditchcrawler]

14 hours ago, Alan de Enfield said:

The air is so compressed it has a consitency almost like Nutela.

Have you seen it then or is that what someone on the internet told you 🙃

[Hudds Lad]

15 hours ago, Alan de Enfield said:

The air is so compressed it has a consitency almost like Nutela.

Compressed even further it becomes solid enough that a skilled Luthier can use it to carve air guitars from