Please help with c6 brake and steering problem after fluid c

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myglaren
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Post by myglaren »

Check the height corrector adjustment, they may have altered it, likely inadvertently as they don't seem to have had a clue what they were doing.

How it it when raised to full height/lowered to lowest position?
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Post by nickyg »

Thanks.

Forgot to mention, as it troubles my logic a little, but the low setting seems to be identical to before. I'll have another check at high in a while, but am reasonably sure it's the same story as low setting, ie not massively higher. It's just on normal there seems to be a discrepancy.

That seems illogical to me, as if a height corrector was disturbed, would all settings be lower/higher to the same degree, relative to the correct position of a properly positioned height corrector?

Or perhaps low and high settings are more finite, as they are nor intended for usage whilst driving etc, and thus can't be compared with the normal ride height setting in such a way.
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Post by KevMayer »

The spongy brakes could be due to air in the ABS actuator block.

I had this once after pressure bleeding my Audi A4. I'd put new fluid in but the brakes were spongy. The cure in this case was to take the car for a drive and brake hard enough to activate the ABS. I did this a few times and then went back to bleed the brake lines again. This cured the spongy feel.

On the height corrector issue, I believe that the high and low settings are independant of the height sensors. The height sensors usually only control the normal ride height.
Cheers, Kev

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Used to have:- Xantia 1.9 TurboD SX. 1996 Blue & 1998 Silver Activa. + 1992 BX TZD Turbo.
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Post by nickyg »

Thanks mate,

I'm looking at a diagram showing a "wheel travel sensor" is this the height senor we're referring to?

Haven't seen a "height sensor" mentioned on the manual I have.

Cheers!
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Post by myglaren »

nickyg wrote:Thanks mate,

I'm looking at a diagram showing a "wheel travel sensor" is this the height senor we're referring to?

Haven't seen a "height sensor" mentioned on the manual I have.

Cheers!
Probably, it is just a potentiometer, not an hydraulic valve setup as per previous Citroens.
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Post by KP »

As your in NI i would imagine you are still covered by trading standards and the sale of goods act as to what they sold you... ie a sh1te service from a wee man!

I would take it to Charles Hurst in belfast or a proper Citroen dealership and ask them to asses the car and how much it would take to put right and then see what a solicitor thinks. You may have to give them a chance at repairing the faults but as they have messed up so badly its perfectly acceptable to see you would have no confidence in returning your car there as they may damage something else that you might not find for a long time after the work was done... loss of faith in good workmanship is what i would suggest be mentioned to them and or a solicitor as the systems on a C6 aren't cheap and if something has been damaged like the steering or brake system then i can imagine the £££ signs blinding you...
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Post by wheeler »

nickyg wrote:Thanks mate,

I'm looking at a diagram showing a "wheel travel sensor" is this the height senor we're referring to?

Haven't seen a "height sensor" mentioned on the manual I have.
I think thats a bad translation from French but yes it is refering to a body height sensor, they probably refer to it as a wheel travel sensor on the C6 as there are 4 of them, one for each corner as opposed to on the C5 it would be refered to as the body height sensor where there is only 1 per axle.
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Post by robert_e_smart »

Nickyg,

Where are abouts in NI are you based?

I have no experience of the C6 or similar C5, but know a citroen specialist in Cavan who does know the C5 very well.

Regards

Robert
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Post by nickyg »

Thanks for the comments everyone, glad to get those service manual labellings straightened out!

I've spoken to Citroen/Donnellys in Enniskillen, and may take it in for an assesment but, to be honest, my opinion of their expertise as a ratio to the price they will be charging leads me to view that as a last best option.

Hallidays Citroen in Derry/Bushmills is a more preferred avenue as they have come across as more knowledgable in any dealings I have had with them.

Ultimately, I hope to glean as much knowledge about this car as possible, as I have always worked on my cars.. just that this one is that much more specialised in certain areas, so I must be cautious!

Robert, thanks for the advice re: Caven. I'm in west Tyrone, so not that far away really. I could be down through that way sometime soon, so will hold that as an option if I can get his details from you!

I hear what has been said regarding my position with this bodger,but I have said my peice to him and don't want to go back near him, really. Obviously this will change if truly unexpected and far reaching issues are uncovered.

For the meantime, I'm relatively confident I can get this sorted with:

-proper, lexia driven brake fluid change
-depressurization, bleeding, new LDS, repressurisation of hydraulic system
-Check of reference heights in Lexia, and adjustment if necessary
-spot check on condition of height sensors/ "wheel travel sensors" and their accompanying mounting points etc

I'm enjoying picking up extra knowledge on these unique Citroen systems.. though, as they say, necessity is the mother of invention!

Ps: what should one look for when checking height sensors condition?

Thanks so much,

Nick
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Post by nickyg »

Sorry for another question, but may I ask hydractive 3 C5 owners if there are warnings in the technical docs to remove LDS cap when raising the car on a jack with the wheels hanging?

I now know there is such a prerequisite-not followed by a mechanic-for the C6 which, as I have mentioned, is a probable source of noise now occuring in the hydraulic system due to air and/or loss of LDS.

My original post outlined the finding of a small quantity (100ml?) of probable LDS under the drivers wheel following several ups and downs on the lift.

Would it be possible that, as the LDS cap was not removed (which I assume is to relieve some sort of pressure introduced when wheels are hanging) LDS may have forced out of, say, the bleed screw on that side? Or perhaps at some other point? There are suspension pressure sensors also at each wheel. The BHI is on that side too.

As I say, sorry for the barrage of Qs! Any thoughts appreciated.
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Post by KevMayer »

I've had a look on 'Citroen Service Documentation' and for the C6 it gives the following warning for a few sequences such as Checking ride height, Topping up LDS fluid etc

"URGENT : If raising the vehicle on a lift, wheels hanging, remove the cap of the LDS fluid reservoir . Refit the cap of the LDS fluid reservoir, once you have lowered the vehicle ."

Looking at the same procedures for a mk 1 or Mk 2 (facelift, not german) C5 it doesn't give the same warning.
Cheers, Kev

02 plate C5 2.2 Hdi Exclusive SE (now 170k miles 03/21).

Used to have:- Xantia 1.9 TurboD SX. 1996 Blue & 1998 Silver Activa. + 1992 BX TZD Turbo.
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Post by nickyg »

Thanks Kev,

All I need to find out for myself now is the reasoning behind this warning, when there seems to be none for the similar system on the pre 2009 C5s!

If I discover that I should least then know the root cause of the noise issues!

Cheers, Nick
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Post by KevMayer »

In the 'Citroen Service Documentation' the suspension of the C6 is described.

There are no height sensors in the same way as the C5 because the C5 just has one height sensor for the front axle and one for the rear axle. The C6 has 4 wheel travel sensors. One for each wheel.

The text describes the sensor as follows:-

"The wheel travel sensor defines the angular position of the suspension lower arm ."

So, it looks like the angle of each of the 4 suspension lower arms is monitored by these wheel travel sensors to provide 4 individual height/stifness feedback sensors
Cheers, Kev

02 plate C5 2.2 Hdi Exclusive SE (now 170k miles 03/21).

Used to have:- Xantia 1.9 TurboD SX. 1996 Blue & 1998 Silver Activa. + 1992 BX TZD Turbo.
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Post by nickyg »

Kev,

Yes you are correct. I've had a look in at them today (had posted on another thread). A rod linked to the lower arm connects to the little wiper/lever on the potentiometer.

Obviously as the lower arm moves it sends the rod up and down in unison.

The potentiometer is mounted on the arm at the point where there is little or no movement and sort of hangs out a little with the rod then dropping down to connect about 150mm along the lower arm from the mounting spot.

Imagine a triangular arrangement, if the bracket was different and the linking rod was connected further towards the wheel then there would be a greater travel and thus the wiper/lever would mover more. The opposite if the rod connected to the arm closer to the mounting point.

I'm sure there's some delicate trigonometry involved in the calculations in this setup, which is why the service docs seems to stipulate the vital importance of maintaining the integrity of the mounting bracket, and to replace if suspected of being imperfect.

I'm getting there slowly but surely in trying to learn about these systems!

:?
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