Lister SR2 Fuel Leak

[cbport]

Hi

 

I have a Lister SR2 with the dreaded (quite a bit of) fuel leaking into sump problem.

 

I have read a lot of the posts on this and the PDF which describes the issue and possible fixes and have been attempting to identify the leak.

 

My question is that the fixes identify the fuel lift pump as a potential source but I cannot seem to find one on my engine. The pipe goes from the header tank via an external filter then directly into the front of the engine behind the side plate covering the injectors. Removing the side plate shows the pipe going directly to the banjo nuts on the injectors.

 

Am I missing something obvious or do not all SR2s have the lift pump?

 

Any help or advice gratefully received.

 

Thanks!

[bizzard]

Hi

 

I have a Lister SR2 with the dreaded (quite a bit of) fuel leaking into sump problem.

 

I have read a lot of the posts on this and the PDF which describes the issue and possible fixes and have been attempting to identify the leak.

 

My question is that the fixes identify the fuel lift pump as a potential source but I cannot seem to find one on my engine. The pipe goes from the header tank via an external filter then directly into the front of the engine behind the side plate covering the injectors. Removing the side plate shows the pipe going directly to the banjo nuts on the injectors.

 

Am I missing something obvious or do not all SR2s have the lift pump?

 

Any help or advice gratefully received.

 

Thanks!

Sounds like its gravity fed. More common on industrial units like generators with overhead fuel tanks.

[Keith M]

If you do have a gravity feed system there will be no fuel lift on the engine

 

So all of the internal fuel will need checking.

 

Also on the back of each injector pump is a screw this also will require checking but check all pipe work first.

 

Because to get to the back of the injector pumps they require removing

 

Keith

[Tony Brooks]

If you do have a gravity feed system there will be no fuel lift on the engine

 

So all of the internal fuel will need checking.

 

Also on the back of each injector pump is a screw this also will require checking but check all pipe work first.

 

Because to get to the back of the injector pumps they require removing

 

Keith

 

and they are selectively shimmed for the injection timing. If you do move the injector pumps make sure that you keep the right shims with the right pump and also be very careful when you clamp them back in. it is easy to twist a pump slightly so the rack/control rod stiffens up.

 

[zenataomm]

My SR2 is below the back deck , while the fuel tank is built into the deck at the base of the tiller, so, as others are saying gravity feeds the fuel to the filter.

I take it you've dipped the dipstick and found the engine is full of oil/fuel?

 

As Keith says check the easy stuff first, i.e. pipe work and joints. Don't forget the spill pipes that run from the injectors back to (probably) the filter or even the tank itself.

 

If you can't find the leak, I'd be tempted to whip out the injectors and single element pumps and have them serviced.

 

Good luck

[cbport]

Hi - thanks for all the replies. There is a header tank so I guess it is gravity fed.

 

I filled up with fresh oil to the mark then ran the engine today with the rocker covers and side plate removed but could not see any obvious leaks in the pipework (the spill pipes lead back to the tank). I put it all back together then ran for an hour and the level increased by about 50mm so I think it must be dumping a fair amount of diesel in there from somewhere.

 

Is anyone aware of any guides on removing the injectors for the SR2? I'm actually on a sailing boat on a mooring so am semi-reliant on the engine to get to shore and a proper mechanic if I can't get all back together again so any advice is much appreciated.

 

cheers

[RLWP]

That is a massive leak, I would suspect the pipe between the two injector pumps

 

Richard

[cbport]

Hi Richard - is that the pipe I can see with the plate off or something hidden? As with the plate off and the engine running I couldn't see anything there. I dried it all with rags and held paper towel round the joints with the engine running and there didn't seem to be anything leaking.

 

Thanks for your help.

[RLWP]

50mm - is that right?

 

50mm of change on the dipstick has to be between five and ten litres of diesel. In an hour that's a very big leak. It can't be the spill side because that dumps straight back to tank, so it has to be on the feed side. And inside the engine that leaves that pipe, the bolts and sealing washers or the bleed screws. A leak of that size from the high pressure system would mean very poor running

 

If it really is 50mm, I bet that pipe is fractured

 

Richard

[bizzard]

The boat being a sailing boat on I presume a sea harbour mooring is probably moving around a bit with wave movement plus possibly heeling with body weight both could keep giving different dip stick readings.

Being gravity fed and by removing the side plate and by watching carefully ''even without running the engine'' a leak on the low pressure side should be quite visible if the leak is really dumping that much fuel into the crank case.

[RLWP]

The boat being a sailing boat on I presume a sea harbour mooring is probably moving around a bit with wave movement plus possibly heeling with body weight both could keep giving different dip stick readings.

Being gravity fed and by removing the side plate and by watching carefully ''even without running the engine'' a leak on the low pressure side should be quite visible if the leak is really dumping that much fuel into the crank case.

As long as you have the fuel tap turned on...

 

Richard

[treddieafloat]

I had the same problem with myTR3 the fault was a leaking injector not being that technical I got RCR to fix it not too expensive and better than me causing more problems

[LesR]

Hi cbport

 

Lets get back to basics on this engine. The problem is an internal fuel leak that is causing the oil level to rise. The fuel lift pump is an external pump fitted outside of the engine casing. So even if you had one and it was leaking it would not drip internally and increase the sump oil level. You say in your opening statement that 'directly into the front of the engine behind the side plate covering the injectors'. This plate does not cover the injectors, these are in fact the injector pumps (one for each cylinder) behind this plate. On top of these two injector pumps are pipes that go to the top of the cylinder head where the actual injectors are housed. To access the injectors remove the two rectangular covers on top of the engine by removing the two nuts on each cover. The covers normally have the name Lister cast into them. I hope this helps.

[RLWP]

Hi cbport

 

Lets get back to basics on this engine. The problem is an internal fuel leak that is causing the oil level to rise. The fuel lift pump is an external pump fitted outside of the engine casing

 

Unfortunately, that isn't correct. When the diaphragm in the pump leaks, fuel flows down into the chamber where the lever lives and directly into the crankcase. This is the most likely cause of a large internal fuel leak on a Lister. Not in this case though

 

Last time I saw a leak capable of raising the oil level by 50mm in an hour, it was on an ex working boat with a fractured feed pipe. This happened due to a loose injection pump clamp allowing the pump to shuffle about and the pipe fatigued

 

Richard

[cbport]

Thanks again all - firstly my mistake in still getting to grips with the metric system, it was a 5mm rise not 10! So half a centimetre in new money.

 

It is a definite leak as I first noticed the level rising a while back and it was creeping way up the stick. After an oil change the level does rise even allowing for the movement of the boat (I'm checking when the engine is cold and the boat is level).

 

The engine runs sweetly after an oil change with 40psi startup pressure and drops to 25 after a couple of hours or so which seems to be OK for these engines from the manual. If I leave it to build up the diesel level the startup oil pressure drops off over time.

 

To summarise what I checked yesterday I had the 2 rocker covers off checked that the fuel pipes were not touching the rocker arms when running. I looked for leaks around the injectors and pipes then with the top side plate off I looked for leaks around the injector pumps. Side access isn't great (28' boat) but with a head torch on and a bunch of paper towel I could not see any obvious leaks with the engine running and the covers off.

 

Under the rocker covers there looks to be 2 pipes coming back from the injectors to the fuel tank which I guess are the 'spill' or overflow pipes? These feel like they could be tightened further but I'm not sure they would respond well to overtightening, is that correct? I checked as carefully as I could for leaks there but could not see any. They look like an olive fitting. If these can be cranked down tighter then I could start there.

 

I checked the nuts holding the injector pumps down and these were tight. The large nuts on the banjo fittings connecting the injector pumps are tight with no signs of leakage. There is a nut with a screw slot on the back of each injector pump, these were both tight with no sign of leakage

 

So would the next step be removing the injectors or the injector pumps or something else? If it removing the injectors/pumps does anyone know of a guide or manual that covers this?

 

Thanks once again - it's great to see people still using these engines.

[RLWP]

5mm is more what I was expecting

 

It is OK to tighten up the spill rail pipes on the injectors. They have a brass nipple brazed onto the end. If you are going to do that, why not completely undo them first and see if the pipe falls in two

 

Richard

 

MORE: See if this helps: http://www.canalworld.net/forums/index.php?showtopic=80008

Edited April 27, 2016 by RLWP

[zenataomm]

50 mm = 2 inches

5 mm = 1/5th inch ....... more or less.

 

I think most of us reckoned you might have gotten your measuring'ments a bit awry, but we were all far too polite to challenge you.

 

As Richard says undo the pipes in preparation for whipping out the element pipes and injectors, there could be a split in one of them.

If not you've only got to undo the retaining bolts on the saddles holding the injectors, and those gripping the pumps (don't forget to undo the pump rack that adjusts both pumps equally, and don't lose or mix up the shims under each one.)

 

Question to RLWP - Why is it the copper rings that sit between the injector nozzles and the heads are never there, even when I fitted them myself a couple of years ago? Where do they disappear to?

[Tony Brooks]

Something seems to be missing here, but maybe its my misunderstanding.

 

1. There are two union nuts on each injector the smaller leak off union and the larger injector pipe union. Leaks from the bottom of the injector pipe union can be hard to spot. Have you tightened both nuts on each injector?

 

2. I can see no mention of the bleed screws on the injector pumps. There may be ordinary hexagon screws with or without a screwdriver slot sealed with a soft/copper washes located between the big fuel feed banjo and the injector pipe at the top of the pump. You may find those screws secure a small banjo with a thin pipe running upwards to each pump. This is supposed to make the engine self bleeding but the thin pipes are prone to vibration failure.

 

Before taking the pumps out I would dry everything off and wrap all the points mentioned in clean kitchen towel. Then run the engine for a short while (idle will be fine). When you take the towel off you should be able to see the difference between oil and fuel stains/marks.

Edited April 27, 2016 by Tony Brooks

[RLWP]

Never had a problem with the copper ones.i have with the fibre ones.

 

What usually happens is a leak from the o ring at the top because it is sitting too high. Probing the top of the head generally showd the solid metal is actually three or four fibre washers. I have made a tool to cut them out

 

Richard

[cbport]

Thanks all - I'll have another crack at checking the pipes as advised and then if no joy I'll try removing the injectors and see what I can find.

[zenataomm]

If you remove the injectors reconnect them upside down to their supply pipes while they are outside the cylinder head. When you crank the engine you'll be able to observe the spray pattern and also watch for leaks at the unions.

 

HOWEVER ~ Do not attempt to do this without placing a drinking glass upturned over the business end of the injector, so there is a barrier between you and the spray.

In case you didn't take that last bit on board, I'll repeat it .......

 

HOWEVER ~ Do not attempt to do this without placing a drinking glass upturned over the business end of the injector, so there is a barrier between you and the spray.

 

As there is a possibility you don't see the danger I'll put it another way ......

HOWEVER ~ Do not attempt to do this without placing a drinking glass upturned over the business end of the injector, so there is a barrier between you and the spray.

 

The danger being the release pressure from an injector is high enough to force diesel through your skin, which is life threatening. If it hits your eyes it can permanently blind you.

 

Neither of those two outcomes is in any way desirable.

 

Stay safe stay happy.

[bizzard]

If you remove the injectors reconnect them upside down to their supply pipes while they are outside the cylinder head. When you crank the engine you'll be able to observe the spray pattern and also watch for leaks at the unions.

 

HOWEVER ~ Do not attempt to do this without placing a drinking glass upturned over the business end of the injector, so there is a barrier between you and the spray.

In case you didn't take that last bit on board, I'll repeat it .......

 

HOWEVER ~ Do not attempt to do this without placing a drinking glass upturned over the business end of the injector, so there is a barrier between you and the spray.

 

As there is a possibility you don't see the danger I'll put it another way ......

HOWEVER ~ Do not attempt to do this without placing a drinking glass upturned over the business end of the injector, so there is a barrier between you and the spray.

 

The danger being the release pressure from an injector is high enough to force diesel through your skin, which is life threatening. If it hits your eyes it can permanently blind you.

 

Neither of those two outcomes is in any way desirable.

 

Stay safe stay happy.

Pretty much impossible on a Lister SR engine without an extended feed pipe and then you have to delve behind the side plate to try and fit it.

[RLWP]

Pretty much impossible on a Lister SR engine without an extended feed pipe and then you have to delve behind the side plate to try and fit it.

 

Or turn the injector pipe upside down, then it sticks out of the side

 

Richard

[bizzard]

 

Or turn the injector pipe upside down, then it sticks out of the side

 

Richard

Oo arr, I forgot that.

[zenataomm]

Pretty much impossible on a Lister SR engine without an extended feed pipe and then you have to delve behind the side plate to try and fit it.

 

Doh Blizzard!

 

If you remove the injectors reconnect them upside down to their supply pipes while they are outside the cylinder head.