C5 front suspension stuck at highest setting

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GiveMeABreak
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Re: C5 front suspension stuck at highest setting

Post by GiveMeABreak »

You should never re-use the LDS you have taken out from bleeding. LDS fluid is hygroscopic - which means that it absorbs moisture from the air. This can be bad for the hydraulic system and affects the properties of the oil if you then reuse the reclaimed LDS fluid that has been exposed to the air. It's another reason why half used bottles of LDS should not be kept for any period of time as it will contaminate the fluid.

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Re: C5 front suspension stuck at highest setting

Post by xantia_v6 »

GiveMeABreak wrote:
14 Dec 2019, 12:32
LDS fluid is hygroscopic - which means that it absorbs moisture from the air.
Do you have a source for that? My understanding is that LDS is not hydroscopic. It is of course susceptible to any water vapour that condenses on the walls of the container.

I would agree that it is not good practice to re-use it, but just for cleanliness, and for removing from the system any debris suspended in th fluid, such as wear particules from seals.

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Paul-R
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Re: C5 front suspension stuck at highest setting

Post by Paul-R »

xantia_v6 wrote:
14 Dec 2019, 17:46
GiveMeABreak wrote:
14 Dec 2019, 12:32
LDS fluid is hygroscopic - which means that it absorbs moisture from the air.
Do you have a source for that? My understanding is that LDS is not hydroscopic. It is of course susceptible to any water vapour that condenses on the walls of the container.

I would agree that it is not good practice to re-use it, but just for cleanliness, and for removing from the system any debris suspended in th fluid, such as wear particules from seals.
That is my understanding also. A mineral oil, whether synthetic or otherwise, is basically hydrophobic.

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Re: C5 front suspension stuck at highest setting

Post by GiveMeABreak »

Apart from the references and cautions "A container of LDS fluid that has been opened should be resealed and kept in a clean place. A container of LDS fluid should be used up within two weeks of being opened. After this, any LDS fluid that has not been used must be disposed of."

I believe the main constituent is a polyalphaolefin which is slightly hygroscopic - but although water is non soluble in LDS itself, it probably attracts the moisture from air to some degree.

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Paul-R
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Re: C5 front suspension stuck at highest setting

Post by Paul-R »

I would love to test the boiling points of virgin and used LDS to see if there's a difference. Having said that I don't see how high temperatures would be achieved as LDS isn't used for the braking system as LHM was.

PAOs are "distinctly hydrophilic". See https://www.machinerylubrication.com/Re ... oil-choice section "Relation to Water".

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Re: C5 front suspension stuck at highest setting

Post by GiveMeABreak »

It depends a lot on the chemical composition of the oils used and the other constituent parts for the end product, but that's a topic for another time I think.

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Re: C5 front suspension stuck at highest setting

Post by zeeshanzaki »

Thank you for your valuable advise.
I will buy new lds once i get the pump and make sure its working before puting into the car.

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Re: C5 front suspension stuck at highest setting

Post by zeeshanzaki »

Can't find the pump in here in Australia. Is there anything I can do with the motor like bypassing connector and connect directly to the motor for the time being.
If anyone from from Australia replaced their pump in the past and have old pump please let me know.
Thanks

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Re: C5 front suspension stuck at highest setting

Post by GiveMeABreak »

Might be worth signing up at ausssiefrogs:

http://www.aussiefrogs.com/forum/index.php

You may have more luck with a used pump from the locals.

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Re: C5 front suspension stuck at highest setting

Post by zeeshanzaki »

I decided to use automotive relay to see if the pump works or not till I find pump. It works fine when I tested out of the car, but doesn’t work when I fitted in to the car. Its now showing serious suspension fault. I tried pressuring tank using empty garden spray which perfectly fit to small pipe on the side of lds tank but didn’t work.

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Re: C5 front suspension stuck at highest setting

Post by xantia_v6 »

zeeshanzaki wrote:
23 Dec 2019, 11:48
I decided to use automotive relay to see if the pump works or not till I find pump. It works fine when I tested out of the car, but doesn’t work when I fitted in to the car. Its now showing serious suspension fault. I tried pressuring tank using empty garden spray which perfectly fit to small pipe on the side of lds tank but didn’t work.
Can you give a bit more explanation of what you did?

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Re: C5 front suspension stuck at highest setting

Post by zeeshanzaki »

I used 4 pin relay similar to the horn relay. I connected battery 12+ to pin 30 and other pin 87 to the pump. Other two pin, pin 85 connected to 12+ exciter and pin 86 to ground. When I applying 12v to pin 85, it connects main 12v pin 30 to pin 87 provides power to the motor. This works perfectly out of the car.

viewtopic.php?t=56094


In the above thread someone used the relay and make it working. However his motor burned due to some other reason.

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Re: C5 front suspension stuck at highest setting

Post by ksanturion10 »

Maybe you have a burned power supply fuse already, if doesn't want to run in the car.
But generaly speaking, if the connector had melted, because of bad pin contacts, I don't believe a relay could improve the situation.
Also this pump motor seems to have been refurbished at some time before, so the repair might of been not very successful.
I would of checked first rotor windings for shorting over the shaft or core lameli, and also the whole brush holder assembly.
If I was you, I would try to solder the thick wires, as I did already to my heater blower motor ;)

BR
Martin

zeeshanzaki
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Re: C5 front suspension stuck at highest setting

Post by zeeshanzaki »

The maxi fuse is fine after i did this test.

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Re: C5 front suspension stuck at highest setting

Post by zeeshanzaki »

I found the pump but it is from 2007 HDI, do you think it will be compatible with 2001 v6. I am going to swap the motor and want to make sure that if it can be attach to the pump.