Backend wont rise

kiwi · Post by **kiwi** » Tue Jan 13, 2009 9:14 am

About time my BX had another problem!

Replaced the Leaking FDV, then the accumulator that was leaking and now couple 100km later the Stop light is on for the Hydraulics and the suspension wont rise. Happened last week so checked the fluid in high all was fine problem solved. Then tonight back end wouldnt pressure.

Cant remeber what the cause would be so better ask is it what i chaged or something I forgot about? Or worse muck got in?

DLM · Post by **DLM** » Tue Jan 13, 2009 6:30 pm

More details needed. Is it just the rear end that's still earthbound, does the front rise, are the warning light on?

DLM · Post by **DLM** » Tue Jan 13, 2009 6:31 pm

erm ... meant "IS the warning light on".

kiwi · Post by **kiwi** » Tue Jan 13, 2009 10:51 pm

More detail he asks

Well took it for a drive today the Red Light Hydraulic one that is comes on seems particulary under braking. The back end is slow to rise! Did notice that whilst standing a clicking when you touch the brake pedal. Tried to isolate it but its deceptive seems to come from around the Height Correctors.

Backend seems to be the issue or at least gives the illusion and its also seems to be more apparent when the brakes been touched. Thats when the Light comes on.

Hydraulic Fluid OK! No leaks at all them been cured with the FDV/accumulator replacement.

Another damn frustrating fault that I am once again on my own to fix without specialist knowledge locally.

Way2go · Post by **Way2go** » Wed Jan 14, 2009 12:16 am

kiwi wrote:Did notice that whilst standing a clicking when you touch the brake pedal. Tried to isolate it but its deceptive seems to come from around the Height Correctors.

Perhaps you have a genuine problem with the infamous & regularly blamed doseur valve?

kiwi · Post by **kiwi** » Wed Jan 14, 2009 12:53 am

Im thinking that or the rear height corrector.

Just come in form another test drive basically all fine got to the end driveway which has a step ramp to the road. Touched the brakes and the light came on when I got out onto the road could feel the back end had collapsed. Managed to get it back up to get back up the drive without grounding

Its an intermitant problem on hte earlier test I started thinking faulty light or something similer. The fluid has a brownish tint to it so could be dirt?

Silly question time!

Would running Hydraflush help or is it yet another part replacement? But which one?

Geoffrey Gould · Post by **Geoffrey Gould** » Wed Jan 14, 2009 10:54 am

Hi it does sound as if a clue might be in the brown-ish colour of the LHM , can you suck or syphon it out, I say that so the tank is not disturbed and you can see what there is in the bottom, I say this because I had a unexplained happening (still don't know.) Checked the LHM one day and it didn't look right and found some 3" of "water" in the bottom of the tank, I say looked like water I wasnt going to taste it. That caused All sorts of fun. Not. Otherwise check the return from the doseur.
Good luck.
Geoff.

kiwi · Post by **kiwi** » Wed Jan 14, 2009 8:08 pm

As this is a problem I have never encountered before simply because there is NO external LEAK.

Whats weird is now that the warning lights on but there is no visible problem either. Well nothing apparent

So basically I got a reluctant Rear end to rise a Warning light that did come on with the Brake thats now on all the time and Hydraulic Level thats fine!

But got still brownish tinge to the fluid which says to me needs a flush! Despite being pumped full of couple litres of LHM when the leaks were around.

Otherwise check the return from the doseur.

How do I do that?

I am even more reluctant now to use the Spare 19TRS for donor parts!

Geoffrey Gould · Post by **Geoffrey Gould** » Wed Jan 14, 2009 10:26 pm

Hello Go to the top of the Technical section and go to 'That sinking feeling' return pipe is the one nearest to the foot pedal end of the doseur.
Cheers.
Geoff.

kiwi · Post by **kiwi** » Wed Jan 14, 2009 10:41 pm

Thanks for that yes had a read through that But I am uncertain what I should be looking for?

As in what would not be right! Found the returns easy enough just not sure what to look for as in a problem.

Geoffrey Gould · Post by **Geoffrey Gould** » Thu Jan 15, 2009 1:45 pm

Hello this is how I see it, there can not ever be a 'perfect' hydraulic seal and they all weep a bit which is an advantage, because imagine a rear suspension strut for example with a perfectly sealed piston, great no leaks but behind the seal the piston and bore of the cylinder would be dry, have no lubrication and be subject to wear and corrosion and may well seize so the answer is simple, provide a very Small Controlled Leak hence all the leak return pipes, small bore plastic clear ones being an example.
An occasional drip being OK, may be a couple of drips a minute. With time and wear then it may increase to a trickle or even a flood enough to blow off the return pipes, front suspension strut return pipes being an example.
So a drip or three OK a trickle not good. So because of the return pipes a leak does not have to be visible to be present, a piece of visable clear pipe from doseur to the LHM tank or into a jar and see what the return leak is like, put foot on brake pedal press and hold if you get a "flood" of LHM then you have trouble.(engine running of course).Try it, see what happens and let us know.
Cheers.
Geoff.

DLM · Post by **DLM** » Thu Jan 15, 2009 6:44 pm

On the subject of the lhm: If it's brown.... then I'd change it and clean the filters & tank out before going any further.

Apologies if my previous post seemed a bit abrupt - I was a bit pushed for time when writing it. I get the feeling that Geoff is suggesting you check the return from the doeseur at the reservoir end - there are photos/diagrams on a couple of websites showing which return pipes are which, and telling you what to do. Was definitely on the old Japanese BX site now only on web archive.

kiwi · Post by **kiwi** » Thu Jan 15, 2009 7:07 pm

Thanks guys your help is appriciated and yes do realise that sometimes we never quite write what we have thought about.

The LHM is priority to be done as soon as I can get some Hydraflush from somewhere. From memory 5ltr container should be able to do both BXs at the same time?

Unless theres a visible leak I dont want to replace anything if i can avoid it! My memory of the Octopus replacement and the subsequant problem with a seized HP pipe o the height corrector in the other BX is still fresh in my mind.

***Important Question Though*** One I feel a bit dumb to ask! Is it safe to continue driving the BX say another 300km with that redlight on? Or will I stuff something else up? Obvious if the back end or brakes go I am going to stop either way.

Geoffrey Gould · Post by **Geoffrey Gould** » Thu Jan 15, 2009 8:12 pm

Hi yes I was suggesting a piece of clear pipe from the doseur return to either the LHM tank or a jar.clear pipe ( length of windscreen washer tubing,most useful stuff.) so that you would stand a chance to see what was happening when you were pushing the brake pedal, I am sorry that I didn't make that clear.
Not replacing anything unless there is a visable leak is fine But the point is that hydraulic leaks via the return pipes are not visable in the way of LHM all over the floor.
As regards driving the car with the STOP light on that is up to you, where brakes, steering and suspension are concerned to me Stop means Stop NOW.
Sorry if shouting at you may offend you but having suffered a total brake on a commercial vehicle going down a steep hill some 45+ years ago the memory is still quite fresh and I would hate the same kind of thing to happen to you.
Take care.
Geoff.

Geoffrey Gould · Post by **Geoffrey Gould** » Thu Jan 15, 2009 10:19 pm

OPPS. That should have read ' a total brake Failure'.
I must learn to read things properly,I must learn to read things properly,I must le------------.
Cheers.
Geoff.