Changing LHM/Hydraflush on Xantia (with pics)

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andrewc
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Changing LHM/Hydraflush on Xantia (with pics)

Post by andrewc » 14 Aug 2007, 11:15

Hi everyone,

I put hydraflush in my Xantia at the weekend to see if it solved the problem of the dropping back end, although it needed flushing anyway.

You can choose to disconnect the pipes from their connectors if you want, but you don't have to. The main problem in getting the reservoir out is the clip bar on the left hand side holding the pipes. Once this is unclipped, the reservoir can be tipped to the side and the filter unit removed (of course you should remove as much lhm as possible before tipping it).

So heres how I did it:-
Hydra1.jpg
Hydra2.jpg
Here is the clip:-1) Set car to lowest height settings to return as much fluid as possible to reservoir.Switch off and depressurise system.

2) If you're going to siphon it out by sucking on the pipe, make sure you have a transparent pipe, and get one with a large diameter, and that's large enough to dangle into your fluid bottle.
Hydra3.jpg
Hydra4.jpg
3) I got about 3 litres of fluid by siphoning, and there was about another litre left in the reservoir.4) Unclip the black bar from the front of the reservoir, and remove from back.
5) Remove the two nuts holding the reservoir to the car.
Hydra5.jpg
Hydra6.jpg
6) Using a flat blade screwdriver, slide the top of the clip to the rear of the reservoir until it comes off the rail.7) You can lift up the reservoir now. You'll still need to remove the bottom part of the clip though.
Hydra7.jpg
Hydra8.jpg
Note the spike on the bottom of the reservoir and the hole it goes into.8) Push the bottom of the clip away from the reservoir and it should come off easily. It's probably easier to use your thumb for this:
Hydra9.jpg
Hydra10.jpg
9) Tip the reservoir to the left and you can lift up it up enough to remove the filter unit.10) Unhook the small metal clip holding the filters in. Twist the conical one and pull down - the D shaped one is held on by the clip and should just pull off.
Hydra11.jpg
Hydra12.jpg
11) Place a plastic bag around the filter unit while you're cleaning the other bits to protect it.12) Give both filters a bath in either petrol or paraffin. You might use a toothbrush to clean inside, but be careful not to damage them.
Hydra13.jpg
Hydra14.jpg
When you've cleaned them off, give them a final rise in new petrol/paraffin.I also found this in the tank. It looks like the end off one of those battery acid testers. Perhaps someone tried to remove fluid in the past and dropped the end in?
  • 13) Wipe off the reservoir, and pour some petrol/paraffin in and slosh it around. I found about a litre of fluid left in the reservoir.

    Fitting is largely a reversal of the above:-
  • 14) Refit filters to head. Insert the conical filter first and twist into place. Then replace D filter and push clip into place. Put filter unit back into reservoir.
  • 15) Refit reservoir into car. This is a bit fiddly, as you have to get it lined up with the spike over the hole as well as over the bolts.
  • 16) Secure two bolts at the back and replace black bar on top.
  • 17) Add about 3 litres of new hydraflush/lhm, then restart engine.
  • 18) Run for about 2 minutes to remove air from the system, then repressurise the system and set car to maximum height. It could take several minutes before anything happens, When the car rises, watch the level float and add more fluid as required.
  • 19) Move car up and down several times to ensure everything is bled, and check fluid level again.
    I've never changed the fluid before, and it wasn't as difficult as I imagined. The only real problem is getting the clip off the tank.
Andrew

andrewc
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Post by andrewc » 14 Aug 2007, 13:14

I should add that you also need to bleed the brakes, as they are a dead end in the system. But it started raining, so I decided to leave that until next weekend.

Andrew.

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CitroJim
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Post by CitroJim » 14 Aug 2007, 14:17

Good work Andrew, well done :wink:

Most valuable :D Always good to have a show of pictures. They really are worth a thousand words!

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Re: Changing LHM/Hydraflush on Xantia (with pics)

Post by Hell Razor5543 » 28 Sep 2012, 19:01

The best way to bleed to brakes is covered elsewhere in this forum, including the order to do them in. A good quality spanner is essential.

You are more likely to round the nipples off, rather than snap them. I have had this happen to me, and then had to struggle to remove it (fortunately it was one on the rear brakes). Now, when I have to work on the brakes for the first time I will remove each nipple and put a smear of copper slip grease onto the threads (but not down any further, to prevent any LHM contamination) to make my life easier next time I work on the brakes.

Plan ahead. If I intended to work on the brakes next weekend I would look at the nipples this weekend, and if I thought they were seized, spray them with Plus-Gas daily until I started working on the brakes. With any luck, the nipples should move easily.

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Re: Changing LHM/Hydraflush on Xantia (with pics)

Post by CitroJim » 28 Sep 2012, 19:06

Hell Razor5543 wrote: Plan ahead. If I intended to work on the brakes next weekend I would look at the nipples this weekend, and if I thought they were seized, spray them with Plus-Gas daily until I started working on the brakes. With any luck, the nipples should move easily.
I second that excellent advice and doing just that I can safely say that I've never had a problem with any Hydraulic Citroen nipples at all, even really crusty ones. The advice of a good spanner too is excellent. If you need to 'crack' an unknown nipple use a single hex 8mm 1/4 drive socket rather than a bi-hex ring spanner of questionable quality; never use and open-ender as that will surely round off...

Xantidote
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Re: Changing LHM/Hydraflush on Xantia (with pics)

Post by Xantidote » 28 Sep 2012, 19:57

Hell Razor5543 wrote:put a smear of copper slip grease onto the threads
As well as applying a little copperslip grease to the threads, I smear a fillet of grease around the nipple after tightening, to prevent the ingress of water into the threads. Belt & Braces :)

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Re: Changing LHM/Hydraflush on Xantia (with pics)

Post by Raul » 03 Apr 2015, 19:09

Hi
Using a flat blade screwdriver, slide the top of the clip to the rear of the reservior until it comes off the rail
I have a guestion about the clip that holds the pipes on the side of the lhm tank. Is it possible to slide the clip off the rail when all the pipes are connected to it?
I am going to change LHM on my xantia and I have never done it before. I looked at the pipes and the clip and tried to slide the clip off but it seems there is not so much room and flexibility in pipes to get that clip off. Should I release the tank at first and then try to release the clip?

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Re: Changing LHM/Hydraflush on Xantia (with pics)

Post by Hell Razor5543 » 03 Apr 2015, 19:33

The clip can be removed from the tank. IIRC you unclip it from the bottom, and then it can come away.

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chinkostu
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Re: Changing LHM/Hydraflush on Xantia (with pics)

Post by chinkostu » 03 Apr 2015, 21:51

I removed all the pipes from the top instead. If you replace with worm type hose clamps it makes the job much faster next time round

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Re: Changing LHM/Hydraflush on Xantia (with pics)

Post by Stickyfinger » 03 Apr 2015, 22:12

Nice guide....thanks
I have that very job soon on the Activa however I have a question

?? > as it is new to me and I do not know everything about the car I intend to do "all those jobs"
.............
should I use Hydraurincage then do this
or ............Do this, wait then use the Hydraurincage and then a change to fresh ?
Last edited by Stickyfinger on 03 Apr 2015, 22:13, edited 1 time in total.

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chinkostu
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Re: Changing LHM/Hydraflush on Xantia (with pics)

Post by chinkostu » 03 Apr 2015, 22:13

I'd rinse it out and use hydroflush/cincage as that'll clear the crud out of the rest of the system :)

Northern_Mike

Re: Changing LHM/Hydraflush on Xantia (with pics)

Post by Northern_Mike » 04 Apr 2015, 00:46

I'd just put fresh LHM in it to be honest. I've hydraflushed 4 different Cits now and never noticed the difference nor the hydra flush being filthy when it's come out. I did my Activa, rhe LHM was disgusting, like old beer with bits in. Hydraflushed it, 3000 miles, cmae out clean as a whistle. Should I end up with another, I'd just change the LHM and ensure the tank and filters are clean. Seeing as you'll likely put new spheres and some bits of new pipework on it, be refurbing the calipers etc - I'd imagine you'll service and clean the electrovalves and the rams too, it's all going to be pretty clean anyway so wasting 3000 miles of it running of Hydraflush whixh isn't as soft or as lubricating seems pointless to me.

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Re: Changing LHM/Hydraflush on Xantia (with pics)

Post by Raul » 05 Apr 2015, 16:50

I am going to change the spheres as soon they arrive but I have a problem - found dot4 bottle from the boot. I siphoned out ca 3,5 l of oil from the reservoir and the liquid was not green but brownish. How bad could this be if someone has mixed lhm with dot.

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Re: Changing LHM/Hydraflush on Xantia (with pics)

Post by Hell Razor5543 » 05 Apr 2015, 16:52

Old LHM can go to a shade of brown. However, in the owners handbook it says that in emergencies you can use an oil (I cannot remember the grade), but this should be changed ASAP. I now would be strongly inclined to hydraflush the car, to make sure. However, do not leave it in over 3,000 miles (as recommended by Citroen), as it is not as 'greasy' as LHM, and so things could seize up if left too long.
Last edited by Hell Razor5543 on 05 Apr 2015, 16:54, edited 1 time in total.

Northern_Mike

Re: Changing LHM/Hydraflush on Xantia (with pics)

Post by Northern_Mike » 05 Apr 2015, 16:54

It can in theory ruin the seals but just because the bottle is in the boot doesn't mean it's been used :-)

When I drained the LHM from my Activa it was the colour of brown beer with bits in.

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