Xant: suspension behaviour questions

deian · Post by **deian** » 17 Mar 2006, 19:13

Hi, I've got a 98 2.1TD Xantia (Hydractive II), now I was 'excercising' the suspension... putting it up, then down, then back to the middle, but upon going from bottom to the middle i heard a squeeling/whinning noise (me thinks not a belt) coming from what I think to be the hydraulic pump. Is this a bad sign?

Also, how is it suposed to go up/down... in little steps (as it clicks away) quite slow too, reaching most of the way then finishing off the last 1/4 of the movement to the top after a few seconds? or is suposed to be smooth and pretty quick?

So any advice or experiences from anyone who knows?

(It handles amazingly for a big heavy car, really gave it some stick seeing as the roads have dried out, I think a set of good tyres would benefit a lot too, as the suspension leaves a lot of work for the tyres to cope with)

Thanks people.

Post by **Peter.N.** » 17 Mar 2006, 19:36

I think you will find it was the belt, they have to be very tight. If the clicking noise is occuring at less than about 20 - 30 second intervals, once the suspension has settled, you need an accumulator sphere.

Mandrake · Post by **Mandrake** » 17 Mar 2006, 21:29

deian wrote:Hi, I've got a 98 2.1TD Xantia (Hydractive II), now I was 'excercising' the suspension... putting it up, then down, then back to the middle, but upon going from bottom to the middle i heard a squeeling/whinning noise (me thinks not a belt) coming from what I think to be the hydraulic pump. Is this a bad sign?

As Peter said, most probably the AUX belt is slipping, and either needs tightening or replacing. The hydraulic pump puts quite a big load on the belt - approx 1.5 horsepower, in addition to the load presented by the alternator, and (if its running) the air-con compressor.

The pump itself wont squeal, but if its worn it will make a slight "whirring noise" under load. If you turn the steering wheel while the car is stationary (and idling, obviously) and you hear a whirring noise while you hold tension on the steering wheel, this is the hydraulic pump.

Mine whirs quite noticably while doing this, but it isn't anything to worry about. (AFAIK)

Also, how is it suposed to go up/down... in little steps (as it clicks away) quite slow too, reaching most of the way then finishing off the last 1/4 of the movement to the top after a few seconds? or is suposed to be smooth and pretty quick?

How often is it "clicking" while lifting ? An anti-sink model such as yours shouldn't click regularly while the suspension is pressurizing from right down to normal height - it should click once when normal height is reached and then settle into a routine of clicking once per X seconds after the height is stable at normal height.

If X is less than 20 seconds or so the accumulator sphere could be flat. If it's clicking every second or two while the car is pressurizing then its highly likely that the accumulator sphere is very flat or punctured. (Which puts a lot of strain on the hydraulic pump, as it has no compressible medium to pump against)

So are you saying the suspension moves in a series of small jerks as it lifts, and they're in time with the clicks ? If so, definately the accumulator sphere needs replacing.

Does both the front and back move in short jerks, or only the front ? It's quite common for the front to do this if the struts need lubing, but its uncomon for the rear to do it.

If it sounds like the accumulator sphere is indeed faulty, from the above, then I'd suggest replacing it and then see what the remaining "symptoms" are before trying to tackle them independantly.

By the way, it is normal when you go from right down to normal height for it to sit there pumping for about 2 minutes BEFORE the height even starts to lift. This is because setting it right down doesn't just lower the ride height, it lets all the pressure out of the suspension entirely. (For maintainance)

When it repressurizes, it has to pump in 95% of the operating pressure before the car even starts to lift, (about 2 minutes on mine) and then the final bit where it visibly lifts is quite short. (About 20 seconds)

A Hydractive 2 model with anti-sink, such as ours, is the slowest of all Xantia's (apart from Activas) to lift from fully depressurized, as it has the smallest pump and the most number of spheres to fill.

Of course in normal circumstances it doesn't loose much pressure over night so doesn't take long in the morning. (About 20 seconds if everything is good)

(It handles amazingly for a big heavy car, really gave it some stick seeing as the roads have dried out, I think a set of good tyres would benefit a lot too, as the suspension leaves a lot of work for the tyres to cope with)

Well, its not THAT heavy a car...

1250Kg to 1350Kg for most models except the V6... but yeah they can handle very well. What tyres have you got on now ? Mine had 185/65/15 (random brand) on alloy rims when I got it, and it chewed the edges of the front tyres in no time due to *ahem* heavy cornering.

I ended up putting a set of 205/60/15 Michelin XM1's on it, and I'm pretty happy with them. Much better grip, and quieter too.

You want a tyre with reasonably deep tread on the edges of the tyre, with a squareish shoulder, not one of those ones that tapers in the tread depth at the edge a lot, (like my original tyres did) otherwise the suspension geometry will wear the shoulder off the tyre in no time, and will scruff around full lock turns...

In hindsight I think 205/60/15 is *slightly* too high in profile for best cornering, I think the optimum size while still staying within the "normal" range with standard rims is probably 205/55/15, unfortunately they don't make XM1's in 55 profile.

205/55/15 would make the car noticably lower geared though, while 205/60/15 is within 1% of the original gearing of 185/65/15.

Any wider than 205 on the standard rims and the tread is too much wider than the rims IMHO. The 205/60/15 are a "snug" fit in the wheel arch with the suspension right down, but you can still get your fingers in between the wheel and guard though, so no chance of rubbing.

Regards,
Simon

rossnunn · Post by **rossnunn** » 17 Mar 2006, 22:11

Our blue Xant has some pretty wide tyres on, I'd have to look in the morning, hangs on for dear life & I've been pretty stupid from time to time & never had a squeal off them.

deian · Post by **deian** » 17 Mar 2006, 22:13

thanks for all that, the suspension clicks maybe every second or less on the way up and the movements are in time with the clicks, the front and the back aren't in time, sometimes the back will be the last end to come up, and it may be slower, so does that mean two acumulator spheres? Am i right in thinking the 'acumulator sphere is the one one behind the radiator, and is there also another one in the middle back somewhere too?

The power steering also hisses a lot, u can feel/hear it hiss around even the normal corners (not even parking a car on full lock kind of thing).

Thankfully, the brakes are the last to go on these cars in terms of hydraulicness-ecesity.

Tyres are 205 R60 15, standard on mine I think. It's a 2.1 Exclsuive, with 'boring' patterned alloys. Ok though. Better than black steel wheels with no covers like i had on my 106!

Mandrake · Post by **Mandrake** » 17 Mar 2006, 22:36

deian wrote:thanks for all that, the suspension clicks maybe every second or less on the way up and the movements are in time with the clicks, the front and the back aren't in time, sometimes the back will be the last end to come up, and it may be slower, so does that mean two acumulator spheres? Am i right in thinking the 'acumulator sphere is the one one behind the radiator, and is there also another one in the middle back somewhere too?

No, there is only one accumulator sphere, and it's mounted on the front of the gearbox housing behind the radiator. Not to be confused with the sphere which is actually mounted on a bracket ON the radiator corner, which is your front centre hydractive sphere. (The sphere that is switched in to give the front its extra softness in the soft mode)

Ok assuming that clicking is coming from near the front of the car where the accumulator sphere is, clicking every second as the car is lifting sounds like your accumulator sphere is completely flat and should be replaced ASAP.

The power steering also hisses a lot, u can feel/hear it hiss around even the normal corners (not even parking a car on full lock kind of thing).

On mine if I have the windows shut and the fan off I can hear it hissing for normal corners, but I wouldn't say it was loud.

Thankfully, the brakes are the last to go on these cars in terms of hydraulicness-ecesity.

Well, if your accumulator sphere is indeed flat, you don't have much in the way of emergency brakes if the auxillary belt driving the pump breaks.

The accumulator sphere is (among other roles) a source of emergency supply for the front brakes should the hydraulic pump fail or the belt break, which can supply about 20 brake applications without the pump working, more than enough to stop safely.

However if the accumulator is dead flat as soon as the belt broke you'd have no front brakes....only rear brakes....so its pretty important to have a good accumulator sphere for safety reasons, and because it doesn't directly affect the ride quality it can get overlooked by some people...

By the way the sphere in the middle at the back in front of the spare wheel that you mention is the "anti-sink sphere" which helps the rear to lose pressure more slowly overnight, but more importantly its also an emergency rear brake accumulator, so if both this sphere and the accumulator sphere are dead flat and the pump belt breaks you have NO brakes.

Tyres are 205 R60 15, standard on mine I think. It's a 2.1 Exclsuive, with 'boring' patterned alloys. Ok though. Better than black steel wheels with no covers like i had on my 106!

Ok well unless you want to go to some custom rims then I think its just a matter of getting a better quality tyre rather than changing sizes if you want a bit better performance...

Regards,
Simon

deian · Post by **deian** » 18 Mar 2006, 11:36

i'm not after better performance from the tyres, they could do with replacing soon though, thats all i'm saying, and they are standard size so that'll stay too, i'm not into this modification thing like some people are unless it greatly benefits the vehicle beyond manufacturer specifications. So new accumulator sphere it is then. GSF for about £20 from what i've heard. It's better than paying for someone's car if the brakes would fail. Or killing myself. Thanks for all that, I may get a rear accumulator too.

deian · Post by **deian** » 18 Mar 2006, 18:08

i can see three in the front, and four in the back... two on both wheels, and one in the middle and the other between the drivers side wheel and the middle one... which is which?

thanks
deian

AndersDK · Post by **AndersDK** » 18 Mar 2006, 18:20

One sphere is fitted directly in conjunction with each wheel - or its suspension cylinder. Pretty obvious what these spheres do. Thats 4 of them.

One sphere seems to be bolted directly onto the engine/gearbox assembly. This is the main accumulator - responsible for the wellknown repeated clicks.
One sphere is sort of fitted on the chassis in the engine bay with 2 large and several small pipes to/fro the base maount. This would be the front Hydractive sphere.
That makes 6 of them.

Under the rear you have one sphere fitted to a base mount with 2 large and several small pipes to/fro. Thats the rear Hydractive sphere.
Another place under the rear you a sphere with a single small pipe connected. This is the antisink - also referred to as the rear accumulator - sphere.
That makes a total of 8 spheres on your Xantia. They are all different - and cannot (must not) be swapped around.

Each sphere is approx £20 (+vat) from GSF.

deian · Post by **deian** » 18 Mar 2006, 18:24

oh so 8 spheres! wow, i thought only 6, why i don't know, i can only find 3 in the front at the moment, the two for each wheels and the one near the radiator, which one is the acumulatoir sphere, this one of the other one that i can't find in the front (near the gearbox somehere)?

AndersDK · Post by **AndersDK** » 18 Mar 2006, 18:35

Are you positive you have 4 spheres in all under the rear ? (as this is a positive indicator of Hyd II and antisink fitted)

deian · Post by **deian** » 18 Mar 2006, 18:50

yes definate, 4 in the rear (i was susrpised too) i have a 1998 2.1TD exclusive.

Mandrake · Post by **Mandrake** » 18 Mar 2006, 20:12

Hmm, not sure why you can't find the 4th sphere at the front. Unless the 2.1TD has lots of stuff in the way, in which case its possible you might only see it from underneath. (WARNING: use ramps or supports etc so you don't get squashed)

It's pretty simple though - the accumulator sphere is mounted on the *gearbox* while the centre Hydractive sphere is mounted on the *body* just behind the radiator. Remember that and you can't go wrong...

Looking from the front the Hydractive centre sphere is actually to the right of the radiator, near the air intake hoses, while the accumulator sphere is more near the middle of the radiator.

Do you have a digital camera to take a pic down the front of the engine bay for us perhaps ? In the 2.0 petrol models the front area where these two spheres are is completely clear, but on the 1.9TD there are all kinds of pipes for the intercooler etc in the way making it nearly impossible to see or reach from the top - maybe the 2.1TD is the same...

Have a look at some pictures on DoubleChevron's site:

http://www.aussiefrogs.com/shane/

Click on 96 Xantia VSX, then click on "Changing the suspension spheres", then scroll down to the 4th picture and it should be abundantly clear. Remember that although they will be in the same place on your car you probably have tons of intercooler and air pipes blocking the view...

Regards,
Simon

deian · Post by **deian** » 18 Mar 2006, 20:45

i'll take pictures tomorrow, i need this issue cleared up too, the engine bay is a little tight yes, i'm sure it's under there somewhere, i did go on my back near the front passenge side wheel but still didn't find it, it must be well hidden away, digital camera job it is then. I thought the accumulator sphere was the one by the radiator, this one certainly clicks a lot when the car is on it's way up though. anyway, pics tomorrow... stay tuned

thanks for the help so far... simon(mandrake... linux user?), and others too.

deian

deian · Post by **deian** » 19 Mar 2006, 16:33

found it, yes there is four in the front too, ok so talking about the lower ones, lets say one is pointing towards the drivers side (the one by the radiator), and the other towards the passenger side (the gearbox one). Which one is the accumulator sphere? I take it the other is the anti-sink. And on the back, which is which, one is in the middle and the other is between the middle and the drivers side. Thanks, I've got pics, but after looking i found them, just need to distinguish the difference now.

Deian

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Xant: suspension behaviour questions

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