when the engine is running at tick over i can hear a tick very 5-10 seconds, i think it is from the pump is this right and if not what is at fault
Thanks Louis
1998 xantia v6 suspension
Moderator: RichardW
Hi Louis -
That would be the hydraulic system's pressure regulator (PR), which has 2 valves cutting in/out, to maintain the hydraulic system's work pressure at approx 150 bar. The cut out valve emits a distinct tick, once the upper pressure limit has been reached.
The PR is located down on front of the engine block, and has the main accumulator sphere screwed on (the large green ball).
Because of the rigid piping, the sound appears to be emitted from the high pressure hydraulic pump (HP). But the HP is not guilty. It simply constantly provides hydraulic pressure, and this is diverted into "idle flow" mode by the PR, when the valve cuts out, thus the HP flow simply routes through the PR back to the reservoir.
The ticking interval is a telltale of the main accumulator sphere condition. This sphere is charged to provide a spare pressure for the front brakes, should the engine stall during drive.
Thus it's imperative for safety reasons, that this sphere is in good condition.
When the ticking interval reaches such short times as 5-10 seconds, you (and other trafficants) are in danger when driving the car !
The short interval tells the sphere is almost flat, thus no longer able to hold a safe spare pressure for the brakes.
Remember that your Xantia has high pressure brakes, which means the brake pedal does NOT transfer your foot pressure to the brakes. Instead the brake pedal works on a "tap valve" admitting pressure to the brakes.
A good (and safe !) system would give a tick interval approx 1.5-2 minutes.
I'd say you should replace the main accumulator sphere asap. It's only approx £20 from GSF, and is fairly easy to DIY.
That would be the hydraulic system's pressure regulator (PR), which has 2 valves cutting in/out, to maintain the hydraulic system's work pressure at approx 150 bar. The cut out valve emits a distinct tick, once the upper pressure limit has been reached.
The PR is located down on front of the engine block, and has the main accumulator sphere screwed on (the large green ball).
Because of the rigid piping, the sound appears to be emitted from the high pressure hydraulic pump (HP). But the HP is not guilty. It simply constantly provides hydraulic pressure, and this is diverted into "idle flow" mode by the PR, when the valve cuts out, thus the HP flow simply routes through the PR back to the reservoir.
The ticking interval is a telltale of the main accumulator sphere condition. This sphere is charged to provide a spare pressure for the front brakes, should the engine stall during drive.
Thus it's imperative for safety reasons, that this sphere is in good condition.
When the ticking interval reaches such short times as 5-10 seconds, you (and other trafficants) are in danger when driving the car !
The short interval tells the sphere is almost flat, thus no longer able to hold a safe spare pressure for the brakes.
Remember that your Xantia has high pressure brakes, which means the brake pedal does NOT transfer your foot pressure to the brakes. Instead the brake pedal works on a "tap valve" admitting pressure to the brakes.
A good (and safe !) system would give a tick interval approx 1.5-2 minutes.
I'd say you should replace the main accumulator sphere asap. It's only approx £20 from GSF, and is fairly easy to DIY.
Yes -
In your V6 you have 2 spheres down there in engine bay. It's the sphere which clearly are fitted onto the engine block, NOT the one residing on the chassis.
Also the unit this sphere screws onto, is the PR, which clearly have a 6mm rigid pipe running from the HP pump.
To replace this sphere, you must first ensure the hydraulic system pressure is nil. You simply open a service valve to release the pressure. This valve is located on the PR (on which the sphere screws on to) - and is seen as a 12mm headbolt, the head protruding the PR body, like the bolt has not been fully winded in, and not retaining anything. It's the ONLY 12mm headbolt in that area - cant miss it.
Simply loosen this bolt 1/2 turn, do NOT unscrew it !
Then using a very sturdy strap tool, unwind the sphere, prepare for a little LHM oil spillage (have rags & papers handy).
Remove the old O-ring seal from PR body, then insert a new LHM wetted O-ring into the PR where sphere screws in. Do NOT do it other way round - i.e. placing the seal on sphere !
Then simply wind on the new sphere, and tension it using handforce ONLY (gloves allowed), like you do an oilfilter. Do NOT tension the sphere with tools, - the seal will twist then !
Start engine and then close the pressure release valve (12mm bolt) on the PR. Again : tension this 12mm bolt sensible, do NOT torque it ! - otherwise the ballbearing under the bolt will deform.
Worst part is to loosen the old sphere, thus it's imperative to use a belt-strap tool, not an oil filter chain tool, as this will most certainly snap.
Once the old sphere is loose, it's a 10min's job - max.
You may decide to do it from underside, with car hoisted, be sure to use safety stands then ! - as the hydraulic suspension may suddenly decide to lower it's height !
Best of luck - you're on to learn how simple it is to service a hydraulic Citroen [8D]
In your V6 you have 2 spheres down there in engine bay. It's the sphere which clearly are fitted onto the engine block, NOT the one residing on the chassis.
Also the unit this sphere screws onto, is the PR, which clearly have a 6mm rigid pipe running from the HP pump.
To replace this sphere, you must first ensure the hydraulic system pressure is nil. You simply open a service valve to release the pressure. This valve is located on the PR (on which the sphere screws on to) - and is seen as a 12mm headbolt, the head protruding the PR body, like the bolt has not been fully winded in, and not retaining anything. It's the ONLY 12mm headbolt in that area - cant miss it.
Simply loosen this bolt 1/2 turn, do NOT unscrew it !
Then using a very sturdy strap tool, unwind the sphere, prepare for a little LHM oil spillage (have rags & papers handy).
Remove the old O-ring seal from PR body, then insert a new LHM wetted O-ring into the PR where sphere screws in. Do NOT do it other way round - i.e. placing the seal on sphere !
Then simply wind on the new sphere, and tension it using handforce ONLY (gloves allowed), like you do an oilfilter. Do NOT tension the sphere with tools, - the seal will twist then !
Start engine and then close the pressure release valve (12mm bolt) on the PR. Again : tension this 12mm bolt sensible, do NOT torque it ! - otherwise the ballbearing under the bolt will deform.
Worst part is to loosen the old sphere, thus it's imperative to use a belt-strap tool, not an oil filter chain tool, as this will most certainly snap.
Once the old sphere is loose, it's a 10min's job - max.
You may decide to do it from underside, with car hoisted, be sure to use safety stands then ! - as the hydraulic suspension may suddenly decide to lower it's height !
Best of luck - you're on to learn how simple it is to service a hydraulic Citroen [8D]
-
David Goddard
- Posts: 138
- Joined: 26 Sep 2001, 04:39
- Location: United Kingdom
- My Cars:
What Anders didn't say is the 12mm screw is tricky to get to on the V6. Lift up the air filter and tie it to the bonnet catch. The Pressure Regulator is then coming into view. There is an oval plate and L shaped bracket supporting hydrualic tube in the way. Remove this oval plate. It's held by a hex bolt and a socket head cap screw. The 12mm pressure releif screw is then just visible. The only way I found to turn it is to use one of those rather nice ratchet ring spanners Halfords sell (Professional Range). There is not enough access otherwise.
A bit too long in my humble opinion ...
Would say approx half of that is good.
The LHM reservoir at LHside (car's) engine bay rear corner, has filter units attached under the manifold where all the rubber hoses connects to. The complete manifold (still with hoses attached) can be unclipped and lifted up. Try lift it up partly to reveal the filter meshes for a visual check.
These filter meshes should be clean oil wetted plastic to look at. If not, the pump is having a hard time to get the fluid in, as the pump is very weak on suction side, despite it's incredible high pressure on output side.
Also the fluid should be clear neon-green in appearance. Any dull-green, even muddy, colour is a bad telltale of fluid replacing service is needed ASAP.
Would say approx half of that is good.
The LHM reservoir at LHside (car's) engine bay rear corner, has filter units attached under the manifold where all the rubber hoses connects to. The complete manifold (still with hoses attached) can be unclipped and lifted up. Try lift it up partly to reveal the filter meshes for a visual check.
These filter meshes should be clean oil wetted plastic to look at. If not, the pump is having a hard time to get the fluid in, as the pump is very weak on suction side, despite it's incredible high pressure on output side.
Also the fluid should be clear neon-green in appearance. Any dull-green, even muddy, colour is a bad telltale of fluid replacing service is needed ASAP.
Hi Louis,
Both Anders and David neglected to say that you should put the car in service position (lowest hight) first, before opening the pressure release valve - otherwise the car will fall on your foot! If you've restricted access to the accumulator from above, its a good idea to put the car on ramps before flattening the susepension - otherwise you'll never get under it again.
//NiSk
Both Anders and David neglected to say that you should put the car in service position (lowest hight) first, before opening the pressure release valve - otherwise the car will fall on your foot! If you've restricted access to the accumulator from above, its a good idea to put the car on ramps before flattening the susepension - otherwise you'll never get under it again.
//NiSk