Air bleed valve

**Markf** · 31st May 2023, 11:53 AM

I've had a problem that I think has been cured.

The problem was that after an unspecified time and distance the car would just stop after a very short period of losing power. A couple of bleed cycles (5 full presses of throttle) would usually see it stagger into life for an unspecified distance.

The first thing I did was to change the injector seals and washers. There was no evidence of any "tracking" on any of the washers. After the change all went well for a couple of months by which time I figured the problem was solved. Then it happened again at a most inconvenient spot - in the right lane just at the east exit from the Burnley Tunnel (Melb). Managed to get it restarted and drove home normally.

At some point Sierraferry alluded to strange things happening if the air bleed valve went bad so I ordered one. I did have a couple of sets of seals and washers so I changed them again as well as my spare injector loom. Again there was no evidence of anything amiss with the washers and the car behaved until now.

My air bleed valve arrived so I spent a few minutes changing it and since then - after about ~500km - no problems. Of course given the intermittent nature of the problem I'm very reluctant to say the problem is cured.

My question is, how do I test the air bleed valve to sure it's either good or bad ? If I can prove it's bad then I can say the problem is solved but if it's still good then the problem still exists and I'm extremely reluctant to use the car to do more than go to the shops that I can walk home from.

**sierrafery** · 1st June 2023, 01:26 AM

I dont think that there is a way to check it "on the bench"...eventually fit back the old one and if the problem comes back then you know

**Markf** · 1st June 2023, 02:45 PM

Originally Posted by sierrafery

I dont think that there is a way to check it "on the bench"...eventually fit back the old one and if the problem comes back then you know

Thanks for that mate. I suspected as much. I found a post on another forum that suggested cutting the end off the plastic bit and having a look at the state of the membrane. What I found would suggest that nothing can get through, fuel air, combustion gasses, etc.
opened air bleed valve.jpg

And here's a "gunkless" pic.

air bleed valve no gunk.jpg

So, considering the amount of gunk in there I reckon I may have cured the problem but as well as that I have become much more proficient at doing injector seals and washers and injector looms.

So if your Td5 is having an intermittent power loss problem and stalling when you pull over and is a bear to start even after a couple of purge cycles followed by minutes, days, weeks or months of perfect running before it does it again then I'd be replacing the air bleed valve. A local diesel mechanic gave me a vital clue. His instincts from years and years in the business is that if it really was one or more injector seals it would be more consistently failing. In another thread Sierrafery also put me on the track of the valve. Changing it will cost about $100 and ten minutes.

Of course seeing as it's a Land Rover I'll still have little niggles in the back of my mind...

**shack** · 1st June 2023, 03:32 PM

The gunk you found is from combustion.

It's in there because the injector seals had failed.

**Markf** · 1st June 2023, 03:46 PM

Originally Posted by shack

The gunk you found is from combustion.

It's in there because the injector seals had failed.

I don't doubt that for a moment. When I first got the car I also got a bunch of receipts one of which was for replacing injector seals and washers by a Land Rover dealer so at one stage the seals and washers have been done. I've since done them three times and on each occasion there was no evidence of the washers leaking - no burn marks or tracking or anything else.
Why did I replace them three times ? Because that's where I thought the problem was. Hopefully I was wrong.

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