Finally found the forum again, - thought it was lost in Cyberspace. Many thanks to all who've kept it going. I'm about to use hydraflush on my Xantia 1.9TD and have come across several references to a step by step guide on another forum by AnderS at the following address: http://citroenz.com/forum/viewtopic.php?t=27
This address takes me to the forum but I get a message saying the topic can't be found and I can't find it with a search. Any suggestions on how I might access the guide?
Thanks
Xantia hydraflush guide
Moderator: RichardW
Xantia hydraflush guide
M Anderson
Could it be this ?
I have saved a good few "tips and tricks" from Anders before they fell out of the forum.
Don't tell me that I caused it.
AndersDK
Joined: 11 Sep 2003
Posts: 1285
Location: Denmark, Jylland East
Posted: Fri Sep 02, 2005 2:47 am Post subject: Procedure for replacing LHM.
--------------------------------------------------------------------------------
As an owner of a hydraulic Citroen -
replacing the hydraulic oil (LHM) is a backbone job
You may need up to some 5L for a full drain/refill. If the previous owner never attended to this - it may indeed be high time ! - to avoid any strange problems popping up everywhere in the system.
The procedure is exactly the same whether it's LHM or Hydracleanse fluid used for replacement.
The LHM fluid must be replaced at 36Kmiles (60Kkm) intervals.
Every third of these intervals, at 108Kmiles (180Kkm), the fluid should be replaced with the special Hydracleanse cleaning fluid made for this purpose. The car should be driven with this fluid for approx 1K - 3K miles (1.5K - 5K km) then this complete procedure must be repeated again, using LHM fluid.
The work commences like this :
Loosen (½ turn) the pressure release screw (only 12mm bolthead found in that area) on the regulator body - found as the device under the sphere on the front of engine. This screw is often referred to as the regulator's "air bleed" screw.
Leave the screw loosened & the height setting in low - untill end of this procedure !
Set the car to lowest height.
Now you've done the best - to get most possible LHM back into the reservoir.
Have a pile of papers & rags ready - the work is a greasy mess - an empty oilcan holding at least 5L should also be handy for the old LHM oil drained out - using a funnel. You will also need a small funnel for priming the feed hose - and 2 new hoseclips for the largest dia hoses.
The green LHM reservoir tin can (square plastic can on Xantia) is located in front RHS of engine on BX'es - at rear LHS on Xantia & CX - several hoses attached. Mark up each of the small hoses - to identify correct refitting later - using cheap coloured plastic strips. Remove all hoses and lead to a jar catching most spillage - try empty the hoses at best. Unplug filler lid. Unclip the 2 spade connectors for the level sensor.
Then unclip the retaining clip holding the reservoir - and carefully lift up the filter "manifold" - place it on papers to drip off. Lift up the reservoir and using a funnel immediately empty the can into your oilcan.
Note that you MAY find a SMALL coin plastic disc - when you empty/clean the can. Save this disc.
Now the reservoir must be cleaned using rags - BEWARE ! - the edge of the hole is razor sharp - skinning your hands - wear gloves !!
Lift out the large plastic disc from bottom.
Now progressively clean the can internally using rags - finally using petrol wetted rags. Consider flushing it with a splash of petrol.
Clean the plastic disc and refit it.
Clean out the reservoir area in the engine bay - observing the rubber ring insert for the can - then refit the reservoir for now.
The filter assembly should now be cleaned - using a soft brush & petrol. You'll notice that the level indicator & the filter meshes may be unclipped for easier access to clean.
Using pipe cleaners etc. - make the filter assembly/manifold look like brand new !
Observe the filter meshes - absolutely no cracks/holes are allowed - new filtermeshes are available cheap as a spare set.
If you found a SMALL coin plastic disc - this belongs to the bottom of the level indicator tube - working as a level shift damper during drive - to avoid flicking fluid level warning lamp.
A word on the pump's suction hose : this must be in good condition to prevent the pump taking in air. Over the years deep surface cracking appears on reservoir and pump studs - telling you a tale. If you find this problem - the hose must be replaced. As an short time emergency you can use oil resistant PVC hosing - i.e. a lenght of common PVC garden hosing - clean of course.
Consider using home made rubber bushings under the hose clamps - to better even out the clamp pressure on the hoses.
It's so very important the hose is air tight - as it's under vacuum - and then you won't see any LHM leaking out.
Refit filter assembly to reservoir when ready - then attach connectors for level warning - and all hoses but the largest one for the pump. Fill reservoir with NEW & fresh LHM (or Hydracleanse) up to some 40mm under edge.
Now you must prepare to prime the pump - since the pump feed hose has been detached - allowing for air getting in :
The large hose to the pump should be filled with LHM using a small funnel. Wriggle around the hose to burp air out - fit a new hose clip - then quickly attach the hose to the reservoir filter and tighten the clip.
Start engine & let idle - then rev it up a bit (some 2500rpm) for 30sec's - then leave it at idle. Now close/tighten the pressure release screw & observe after some hesitation that the regulator starts ticking while pressure builds up in the system.
Set the car to normal height - observe that it raises.
If the pump/regulator does not seem to build up pressure - you have to do the pump priming over again : Stop engine - loosen the pressure release screw ½ turn - car height to lowest - fill the pump feed hose with LHM.
In some very annoying cases - this procedure may be repeated up to 4-6 times before you hit your luck. The secret is the "feeling" of how to prime the pump & feed hose correctly - it's a trial experience.
Once pressure is regained in the system - check the level float on reservoir - top up untill the float slowly hits the glass top. Then set the height to HIGHEST - recheck that the float now is within the 2 red rings.
Now vent the suspension system for any air let in during the above process - Citaerobics. This MUST be done prior to bleeding the brakes.
WARNING : Never road-drive the car in low or high settings.
Finally you have to bleed the brakes. Since these are dead ends in the system (as opposed to the suspension) - this must be done manually - to shift out the old/dirty LHM in brake calipers.
This procedure is just like on any "normal" car - except it's easier :
- you have system pressure available constantly when engine/pump running
Have the engine idle - set height to highest - clamp a piece of wood between drivers seat and brake pedal.
Now remove each wheel in turn and bleed the calipers - untill clean fresh LHM (or Hydracleanse) is seen flowing out. Keep an eye on the reservoir level float - top up accordingly. Discard the bleeded out fluid.
For your reference :
The LHM fluid is based on mineral oil - exactly like the earlier type mineral engine oils.
The LHM fluid has outstanding temperature, lubing & viscosity properties :
Pour point : -62'C
Boiling point : 255'C (raised considerably by the high system pressure)
Non-hygroscopic (does not absorbs water like DOT brake fluids)
The Citroen hydraulic system works with a system pressure within 145-170 bar (some 2500psi) - regulated by the pressure regulator.
This pressure is of course only present in the rigid steel pipes.
(Except for BX/earlier Xantia servosteering 2part hose at radiator - and the front brakes hoses)
Edited by : AndersDK, 21jan04
I have saved a good few "tips and tricks" from Anders before they fell out of the forum.
Don't tell me that I caused it.
AndersDK
Joined: 11 Sep 2003
Posts: 1285
Location: Denmark, Jylland East
Posted: Fri Sep 02, 2005 2:47 am Post subject: Procedure for replacing LHM.
--------------------------------------------------------------------------------
As an owner of a hydraulic Citroen -
replacing the hydraulic oil (LHM) is a backbone job
You may need up to some 5L for a full drain/refill. If the previous owner never attended to this - it may indeed be high time ! - to avoid any strange problems popping up everywhere in the system.
The procedure is exactly the same whether it's LHM or Hydracleanse fluid used for replacement.
The LHM fluid must be replaced at 36Kmiles (60Kkm) intervals.
Every third of these intervals, at 108Kmiles (180Kkm), the fluid should be replaced with the special Hydracleanse cleaning fluid made for this purpose. The car should be driven with this fluid for approx 1K - 3K miles (1.5K - 5K km) then this complete procedure must be repeated again, using LHM fluid.
The work commences like this :
Loosen (½ turn) the pressure release screw (only 12mm bolthead found in that area) on the regulator body - found as the device under the sphere on the front of engine. This screw is often referred to as the regulator's "air bleed" screw.
Leave the screw loosened & the height setting in low - untill end of this procedure !
Set the car to lowest height.
Now you've done the best - to get most possible LHM back into the reservoir.
Have a pile of papers & rags ready - the work is a greasy mess - an empty oilcan holding at least 5L should also be handy for the old LHM oil drained out - using a funnel. You will also need a small funnel for priming the feed hose - and 2 new hoseclips for the largest dia hoses.
The green LHM reservoir tin can (square plastic can on Xantia) is located in front RHS of engine on BX'es - at rear LHS on Xantia & CX - several hoses attached. Mark up each of the small hoses - to identify correct refitting later - using cheap coloured plastic strips. Remove all hoses and lead to a jar catching most spillage - try empty the hoses at best. Unplug filler lid. Unclip the 2 spade connectors for the level sensor.
Then unclip the retaining clip holding the reservoir - and carefully lift up the filter "manifold" - place it on papers to drip off. Lift up the reservoir and using a funnel immediately empty the can into your oilcan.
Note that you MAY find a SMALL coin plastic disc - when you empty/clean the can. Save this disc.
Now the reservoir must be cleaned using rags - BEWARE ! - the edge of the hole is razor sharp - skinning your hands - wear gloves !!
Lift out the large plastic disc from bottom.
Now progressively clean the can internally using rags - finally using petrol wetted rags. Consider flushing it with a splash of petrol.
Clean the plastic disc and refit it.
Clean out the reservoir area in the engine bay - observing the rubber ring insert for the can - then refit the reservoir for now.
The filter assembly should now be cleaned - using a soft brush & petrol. You'll notice that the level indicator & the filter meshes may be unclipped for easier access to clean.
Using pipe cleaners etc. - make the filter assembly/manifold look like brand new !
Observe the filter meshes - absolutely no cracks/holes are allowed - new filtermeshes are available cheap as a spare set.
If you found a SMALL coin plastic disc - this belongs to the bottom of the level indicator tube - working as a level shift damper during drive - to avoid flicking fluid level warning lamp.
A word on the pump's suction hose : this must be in good condition to prevent the pump taking in air. Over the years deep surface cracking appears on reservoir and pump studs - telling you a tale. If you find this problem - the hose must be replaced. As an short time emergency you can use oil resistant PVC hosing - i.e. a lenght of common PVC garden hosing - clean of course.
Consider using home made rubber bushings under the hose clamps - to better even out the clamp pressure on the hoses.
It's so very important the hose is air tight - as it's under vacuum - and then you won't see any LHM leaking out.
Refit filter assembly to reservoir when ready - then attach connectors for level warning - and all hoses but the largest one for the pump. Fill reservoir with NEW & fresh LHM (or Hydracleanse) up to some 40mm under edge.
Now you must prepare to prime the pump - since the pump feed hose has been detached - allowing for air getting in :
The large hose to the pump should be filled with LHM using a small funnel. Wriggle around the hose to burp air out - fit a new hose clip - then quickly attach the hose to the reservoir filter and tighten the clip.
Start engine & let idle - then rev it up a bit (some 2500rpm) for 30sec's - then leave it at idle. Now close/tighten the pressure release screw & observe after some hesitation that the regulator starts ticking while pressure builds up in the system.
Set the car to normal height - observe that it raises.
If the pump/regulator does not seem to build up pressure - you have to do the pump priming over again : Stop engine - loosen the pressure release screw ½ turn - car height to lowest - fill the pump feed hose with LHM.
In some very annoying cases - this procedure may be repeated up to 4-6 times before you hit your luck. The secret is the "feeling" of how to prime the pump & feed hose correctly - it's a trial experience.
Once pressure is regained in the system - check the level float on reservoir - top up untill the float slowly hits the glass top. Then set the height to HIGHEST - recheck that the float now is within the 2 red rings.
Now vent the suspension system for any air let in during the above process - Citaerobics. This MUST be done prior to bleeding the brakes.
WARNING : Never road-drive the car in low or high settings.
Finally you have to bleed the brakes. Since these are dead ends in the system (as opposed to the suspension) - this must be done manually - to shift out the old/dirty LHM in brake calipers.
This procedure is just like on any "normal" car - except it's easier :
- you have system pressure available constantly when engine/pump running
Have the engine idle - set height to highest - clamp a piece of wood between drivers seat and brake pedal.
Now remove each wheel in turn and bleed the calipers - untill clean fresh LHM (or Hydracleanse) is seen flowing out. Keep an eye on the reservoir level float - top up accordingly. Discard the bleeded out fluid.
For your reference :
The LHM fluid is based on mineral oil - exactly like the earlier type mineral engine oils.
The LHM fluid has outstanding temperature, lubing & viscosity properties :
Pour point : -62'C
Boiling point : 255'C (raised considerably by the high system pressure)
Non-hygroscopic (does not absorbs water like DOT brake fluids)
The Citroen hydraulic system works with a system pressure within 145-170 bar (some 2500psi) - regulated by the pressure regulator.
This pressure is of course only present in the rigid steel pipes.
(Except for BX/earlier Xantia servosteering 2part hose at radiator - and the front brakes hoses)
Edited by : AndersDK, 21jan04
2002 C5 2.0i AL4 230,000 km 76372389
-
RichardW
- Forum Treasurer
- Posts: 10871
- Joined: 07 Aug 2002, 17:12
- Location: United Kingdom
- My Cars: MK2 '17 C4GP 1.6 BlueHDi 120
'13 3008 1.6 HDi GripControl - x 996
Few of points of note when tackling a Xantia:
1. when depressuring, do it with the engine running - this keeps the anti-sink valves open (I know there are a few non-anti sink Xantias about, but not many). If the car has hydractive, then keep a door open to make sure the hydractive valves stay open and depressure the centre spheres. I usually shut the engine down 30s or so after opening the bleed screw.
2. getting the tank out is awkward - but it is possible without disconnecting the hoses. On my TD I found it easier to remove the flexible section of air intake hose from the filter to make more access. You will find that the hoses are clipped into a bracket on the side of the LHM tank. Unclip as many hoses as you can (on my VSX there are some hard return pipes that pass through the bracket
). Remove the spring clip and the two mounting nuts, and pull the tank up a bit and off the studs - note that there is a plastic spigot on the bottom of the tank that might be a bit tight. Once you've got the tank up an inch or two, there should be some slack in the bracket on the side - slide the bottom of it backwards so that it disengages from the tank. You should now be able to tip the tank over to the right of the car. Once you get enough tip on, you will have enough free play to pull the filter block out of the tank and remove the tank from the car - depending on how much LHM there is in the tank, it might be necessary to syphon some of it off to get enough tilt without spilling it everywhere. It's best to have an assisstant on hand when you lift the tank out, as you can't put it down because of the spigot. Have the assisstant ready with a shallow pot to stuff under the filter block so it doesn't leak LHM all over the gearbox. Refit it the same way, but it's a bit easier as you can tip as far as you like as you don't refill till after it's in.
3. The Xantias usually self prime easily, as the pump is below the tank. Once in and refilled start the engine and watch for bubbles in the tank. Once these stop, close the bleed screw and put the car in high, and wait for it to rise. Note antisink cars (and especially hydractive ones) take quite a long time to repressure when they've been flat, so just leave it idling and go away for a few minutes - it should be up when you get back. Do the citaerobics, but be prepared for hydractive cars to do some rapid rising or falling as the hydractive valves open and the system pressure equalises.
1. when depressuring, do it with the engine running - this keeps the anti-sink valves open (I know there are a few non-anti sink Xantias about, but not many). If the car has hydractive, then keep a door open to make sure the hydractive valves stay open and depressure the centre spheres. I usually shut the engine down 30s or so after opening the bleed screw.
2. getting the tank out is awkward - but it is possible without disconnecting the hoses. On my TD I found it easier to remove the flexible section of air intake hose from the filter to make more access. You will find that the hoses are clipped into a bracket on the side of the LHM tank. Unclip as many hoses as you can (on my VSX there are some hard return pipes that pass through the bracket
). Remove the spring clip and the two mounting nuts, and pull the tank up a bit and off the studs - note that there is a plastic spigot on the bottom of the tank that might be a bit tight. Once you've got the tank up an inch or two, there should be some slack in the bracket on the side - slide the bottom of it backwards so that it disengages from the tank. You should now be able to tip the tank over to the right of the car. Once you get enough tip on, you will have enough free play to pull the filter block out of the tank and remove the tank from the car - depending on how much LHM there is in the tank, it might be necessary to syphon some of it off to get enough tilt without spilling it everywhere. It's best to have an assisstant on hand when you lift the tank out, as you can't put it down because of the spigot. Have the assisstant ready with a shallow pot to stuff under the filter block so it doesn't leak LHM all over the gearbox. Refit it the same way, but it's a bit easier as you can tip as far as you like as you don't refill till after it's in.3. The Xantias usually self prime easily, as the pump is below the tank. Once in and refilled start the engine and watch for bubbles in the tank. Once these stop, close the bleed screw and put the car in high, and wait for it to rise. Note antisink cars (and especially hydractive ones) take quite a long time to repressure when they've been flat, so just leave it idling and go away for a few minutes - it should be up when you get back. Do the citaerobics, but be prepared for hydractive cars to do some rapid rising or falling as the hydractive valves open and the system pressure equalises.
Richard W
