LHM Leak!

PicassoPigeon · Post by **PicassoPigeon** » 11 Jan 2008, 10:21

Stop light came on yesterday. Put in 2l of lhm and all was ok got me home. Just as i was parking her up Stop light came on again.
Having a look around there is a leak down the back of the LHM tank cant see where its coming from and it looks to only do it when running.

It comes out at a constant trickle NOT a mist so seems not under pressure?

I have taken the LHM tank out but with out running cant see where the leak is from.
Anybody got any idea where to start?

gav425

Thank you.

Post by **RichardW** » 11 Jan 2008, 11:13

The front anti-sink valve is a weak point and that's right under the tank. Usually gives way spectacularly though

Could it be one of the returns to the tank leaking?

PicassoPigeon · Post by **PicassoPigeon** » 11 Jan 2008, 11:31

The steering went heavy but everthing else was fine?

Mandrake · Post by **Mandrake** » 11 Jan 2008, 20:20

gav425 wrote:The steering went heavy but everthing else was fine?

The steering relies on a constant flow of oil to have assistance - as soon as the tank runs low enough on oil that the pump is sucking air, the steering will suddenly get heavy. (VERY bad for the pump running it with no oil flowing through by the way, it will do serious damage to it in a short time)

Meanwhile you still have stored high pressure in the accumulator sphere so brakes etc will seem to be fine - for a short time... After that you are in big trouble. Consider the steering suddenly going heavy an early warning - and pull over.

Regards,
Simon

slim123 · Post by **slim123** » 11 Jan 2008, 20:45

I will bet that the others are correct and it is the anti sink valve leaking.

The valve is below the reservoir and to the rear of it, the valve will be plain ally silver colour and about 4" long with 2 x pipes either side and 1 x pipe in the end (5 pipes in total, I can do maths)

The funny thing about this is that they are a common problem for leaking, but only on the front one, but the back one never seems to fail. They are the same part!!!!

I have spoken to Martin and Phil at Pleiades about these little valves and they say that it is down to the "O" ring grove being too deep at the back, the "O" ring rattles around in it until it wears out and leaks, but as to why it never happens to the back one? well the only explanation can be heat from the engine expanding the ally and making a poor job worse.

I also have seen that they take a little from the housing when fixing these to make the "O" ring sit tighter in it's housing, seems to work well after their care and attention!

Changing it is not difficult, just a bit on the fiddley side, either photo the job first or mark up the pipes, cos when you have five pipes and five holes, it's realy easy to put a couple in wrong.

Regards
Slim

Mandrake · Post by **Mandrake** » 11 Jan 2008, 21:19

slim123 wrote:The funny thing about this is that they are a common problem for leaking, but only on the front one, but the back one never seems to fail. They are the same part!!!!

I have spoken to Martin and Phil at Pleiades about these little valves and they say that it is down to the "O" ring grove being too deep at the back, the "O" ring rattles around in it until it wears out and leaks, but as to why it never happens to the back one? well the only explanation can be heat from the engine expanding the ally and making a poor job worse.

Don't forget the front suspension pressure is a lot higher than an unladden rear suspension too - so my guess would be a combination of higher pressure, and heat cycling from the engine bay heat...(the radiator fans would be blowing hot air right up under the tank...)

Regards,
Simon

HST · Post by **HST** » 11 Jan 2008, 23:01

Apparently coming out in a trickle doesn't necessarily mean it's not under pressure. I've just had a leak where it looked like it was a trickle, but close examination revealed it was a tiny jet (almost invisible) of LHM under high pressure from a pinhole in a power steering pipe dripping off the chassis.

citronut · Post by **citronut** » 12 Jan 2008, 11:56

i have fixed these by just fitting a new O ring, the ones i did the screw cap had vibrated loose and damaged the seal, citroen said the seal is not avalible on its own, i think i found one for the pump fitted, i also did them in situe
regared malcolm

PicassoPigeon · Post by **PicassoPigeon** » 12 Jan 2008, 15:20

it must be coming from there as i can see it shooting straight down from under the rear of the LHM tank. Would any O ring fit as long as its the right size or do i need the one from the main stealer?

Would be nice to do it cheaper than a new valve.

Thank you all so much for your help and advice.
gav425

citronut · Post by **citronut** » 12 Jan 2008, 17:39

it is best to use an LHMcompatable rubber O ring, as LHM can/will deteriarate some seals
regards malcolm