Disco 2 Non-Return valve replace.

So, my parts arrived this morning, so I decided I had nothing better to do this evening. Replaced the air valve, and the fuel non return valve, plus the fuel filter. Seems to have stopped the failing to start issues, but I will wait until the morning before I 100% confirm its resolved the issue...

Air bleed replaced... part number WJN500110

This valve should not have an opening in the end. The "lips" of the valve should be closed, and stop fuel returning back from draining from the pipes... Replace this rubber valve, part number
DA3950

Easy to replace, but I found the pipes a pain to unclip off the brass ferrules. I smeared a little rubber grease on the ferrules when re assembling which really helped.

These are the parts I replaced...

If I was doing this again, I would just buy the whole fuel filter assembly, as you get everything new, and assembled...

tilly2 said:

If I was doing this again, I would just buy the whole fuel filter assembly, as you get everything new, and assembled...

Click to expand...

Especially, as the old filter housings go porous and can break on you when you try undo the fittings.


Cheers

Yes, the fittings were very tight. Took quite a bit of force to break the seal...

Cant remember, but I thing those ferrules are a 3/4 spanner size.

tilly2 said:

Yes, the fittings were very tight. Took quite a bit of force to break the seal...

Cant remember, but I thing those ferrules are a 3/4 spanner size.

Click to expand...

When I undid mine, the fitting did not turn but the filter housing top broke in two...Ooops.
At least you can now get the ducks bill valve easily.

Cheers

Hmmm... started up on the key today, which is an improvement, but after a drive around, I noticed a drop in power... This drop in power is getting to me now... Im errrrrring that its the fuel pump as its an issue of lack of response off the pedal..

Can anyone confirm which port the non-return valve sits in. Looking at LRcat its not the same port as the one I found the valve to be in....

Right, here is a diagram of the filter housing. This shows the non return valve in the rear left port, I found mine was in the rear right port. I shall swap these over today, and see if it makes a difference, and someone previously installed it incorrectly.

Ok, looks like some muppet previously fitted the non return valve to the return from the fuel cooler...

Well that might make it go better!

It's is a real mess around that NRV, it can have logic in both positions that's why some thought to be covered 100% , see the last pic https://www.ebay.co.uk/itm/land-rover-td5-discovery-2-defender-fuel-air-bleed-return-valve-kit/193590650262?_trkparms=aid=1110006&algo=HOMESPLICE.SIM&ao=1&asc=225076&meid=599acca7acf5489399112e8d091bf3ab&pid=100036&rk=2&rkt=12&sd=192379523185&itm=193590650262&pmt=0&noa=1&pg=2047675&algv=DefaultOrganic&brand=Land+Rover&_trksid=p2047675.c100036.m2109 though IMO the engine should start and run well without it here's a discussion : https://www.landyzone.co.uk/land-rover/td5-fuel-issues-starting-issues-fix.319376/

Yes, took the Disco out to the tip, and it ran much better. Still sluggish but ill be getting a new pump next month... let's see.

tilly2 said:

Ok, looks like some muppet previously fitted the non return valve to the return from the fuel cooler...

Click to expand...

Holy thread resurrection
So I've been doing some reading on this subject as mine just winds and winds in a morning until it eventually fires to which has led me here....
so while I do understand what I'm reading, the bit of rubber is none return and the brass is the air bleed, both on the same side of the housing.... What I don't just understand is the quoted diagram showing the pipes and flows, am I right that the high pressure supply does not go through the filter until it has been around the engine?

Means the filter isn't working at 4 bar. I imagine there would be issues if it ran at that pressure with leaks.