TD5 AIR BLEED VALVE in Fuel Filter

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CharlesY

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Hi Guys,
I am repeating this reply with a new subject heading.



Let us know what difference they made.


Hi Shifty,

Not a lot. Still poor to start this morning.
But that may be at least partly due to dodgy fuel.
Now hear this .

Discomania and I jacked up rear right and took off the wheel.

Then using a 19mm spaniard slackened the REAR OUTER pipe nut, that's the easy one on the LEFT looking at it, and nearest.

Undo it completely, and catch the copper washer.

Now examine the end of the pipe. Jammed into it is a small nylon plug thing with three holes in the end of it. Under the three holes is a small flat filter.
Under that is the tiny AIR BLEED HOLE.

All the time the TD5 fuel pump is running, any air in the filter head SHOULD vent THROUGH the little filter then through the little bleed hole, and be dumped back into the fuel tank through the far left connection along with some fuel.

So ... if the little filter in the nylon plug bleed device is blocked with dirt, NO AIR BLEED especially on a first start.

So what I did was carefully to prise the nylon plug thing out of the end of the pipe. It is help in by a small O-ring that comes out with it. Then I SPLIT the end off the thing using a sharp knife, and scraped off the filter thing which is there ONLY to stop the bleed hole from getting blocked - so the filter blocks instead!

The car was parked at about three o'clock, and it's quite cold here. It is now 21.45, and I just went out to start it up. It started better than it has done for WEEKS.

TD5 drivers ...be aware there's an automatic air bleeder hiding in the fuel filter and it can cause poor starting!

If anyone else looks at this, please post findings and news.

Charles Y
 
What do you mean by saying automatic air bleeder? That air valve? I completely removed it. I really dont know what problems i can get if i remove it. Without it cr starts much more better.
 
Found 1 negative effect. If in tank less then 1/3 of fuel i should wait before cranking 10 secs otherwise fuel line will be cloged with air
 
Yeah. You are right shifty. Thats why i will reinstall valve back. But without paper filtr. That is getting cloged
 
I reckon that is the best compromise. Take the filter out as CharlesY discovered and you could consider opening out the bleed hole by a tad to prevent it clogging.
Shifty,

do you say there are THREE bits there,

paper filter

Bleed-hole

and

ONE WAY VALVE?

If so, where's the Goddam one way valve?

Mine was a pig to start this afternoon after sitting three hours.
It has 3/4 tank of fuel in it.

I think I will try running the fuel priming process in the morning.

Once it's running it goes beautifully as usual.

Charles
 
there is only a paper filter and a small hole.. nothing else. maybe you could try to make that hole bigger but then you dont need to remove that paper filter...

How was your TD5 starting? did it cough and emmit white smoke?
 
I think I may have cleared up the confusion regarding the air bleed valve.
I've had a chat with my local LR mechanic and he tells me that some of the very early TD5 engined LRs were fitted with a combined air bleed and one way valve in the fuel filter housing which was basically to prevent the high pressure fuel lines from emptying overnight. However this was discontinued very quickly as they often broke up and sent bits of rubber through the fuel pump. They did try using a fuel filter with a drain back valve (a bit like a cartridge oil filter) but that also had its problems and was never rolled out. He said that if your fuel system is in good condition with no leaks then air can not enter the lines so the fuel can not drain back. If you are having to purge the fuel lines after the vehicle stands for a length of time the cause is normally found to be a dodgy injector O ring allowing air to be drawn in via the camshaft housing causing the high pressure fuel system to drain back to the tank. This may or may not allow fuel to leak into the engine oil depending on how bad the O ring is. Another cause of air entering the fuel system is the quick release fuel pipe connectors to the FPR and the fuel cooler where there is dirt i nthe joint or the pipe stubs have minute scratches on them. You can use some WET WITH PARAFIN very fine (almost flour paper) wet and dry to polish the pipe stubs and flush the hose connectors to make sure that they are clean. He recommends that if you see signs of scratching on the pipe stubs that you change them and the hoses to ensure that they seal perfectly. Hope this helps.
 
Aha i understand now.... I seen some signs of fuel at tube near fuel cooler... But didnt mention it....

Also i talked also with lr mechanic and he said to remove valve from the returning tube that is near frame closest to engine. This tube comes from FPR to fuel filter. And marked as black (as i remember) maybe that is about whIch shifty's mechanic been talking
 
Excatly about that valve i've been talking... i think we need to remove it... there is no need in it. Because fuel system is a closed type, So air cant enter in it. Gonna remove it tomorow. Will write you results
 
Whereabouts exactly is this thing please?
My TD5 Disco is running beautifully but it's a pig to start up.
Clean fuel filter, new glow plugs, injector washers recently done, so what is it?

CharlesY


The non return valve is within the nr 10 connector where it's connected to the filter body(unscrew it and will be there....RAVE doesnt mention it) and the air bleed valve is nr 7 as shown

filter.png
 
The non return valve is within the nr 10 connector where it's connected to the filter body(unscrew it and will be there....RAVE doesnt mention it) and the air bleed valve is nr 7 as shown
Thanks.


As it is easy to get at I will have a look at it tomorrow after I get back from the dentist, assuming the Disco starts and gets me there.

Do you guys take this thing out and fling it, or replace it with one that works?

CharlesY
 
My mechanic told me that valve is placed in a tube closest to engine and frame so opposite one to tube 10
 
Here is the pic from Microcat ..... its nr. 10 as u can see

Callout Part Number Part description
10 VUB5039501KIT - NON-RETURN VALVE

filterru.png
 
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The air bleed valve can be "refurbished" as u said, cutting the filter part of it.....the non return valve is based on it's springiness so u better replace it.


Well I can tell you right now, my TD5 Disco does NOT have one of those valves. It just is not there!

Is it possible to buy one?
 
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