noisy accumulator

fangy · Unread post by **fangy** » 31 Mar 2007, 22:27

Hello, I've been replacing all the spheres on my Xantia, after replacing the accumulator sphere the cars went from clicking every 1 to 2 seconds to making a kind of growl, sometimes followed by a click every 20 seconds or so. does anyone know what could be causing this noise? I also noticed after I parked the car and got out, the front dropped instantly and when I restarted it five minutes later the front came up then went down and then back up again, the accumulator sphere was the right one, I checked the part number with a sphere table I've got, could the the new sphere be causing the suspension to go up and down?
Thanks,
Fangy.

Mandrake · Unread post by **Mandrake** » 31 Mar 2007, 22:46

It sounds a bit like you might have a fault with the Hydractive system at the front - especially the lifting up, falling and lifting symptom.

Does it lift at a normal speed, then drop quite abruptly, then lift at normal speed again ? Thats not uncommon at the rear (mine is doing that again recently, GRRR) but I havn't heard of it happening at the front before.

When you say the car drops when you get out, do you mean it drops just a small amount to correct for the change in weight (which is normal) or drops right down ? (which is not normal)

No comment on the growling noise - seems a bit vauge!

If the regulator cycle time is still only 20 seconds with a new accumulator sphere then there is leakage somewhere in the system. Being a VSX, one of the electrovalves is a possible candidate.

Regards,
Simon

fangy · Unread post by **fangy** » 01 Apr 2007, 00:04

It seems to rise and fall the opposite way, rising quite fast and falling at normal speed, When I get out the car and it drops it isn't by much , so I guess this is normal. The growling noise is hard to describe, it lasts for about a second and happens every 20 seconds or so and every so often it's followed by a click. It seems to be coming from the accumulator because it's quite rhythmical. Is it LHM that leaks from the electrovalves, where abouts on the car are they? I've got a leak from my front strut return pipe (going to fix it tomorrow) could this have anything to do with it?
Thanks for the help,
Fangy.

dnsey · Unread post by **dnsey** » 01 Apr 2007, 07:45

The 'growl' sounds like the normal sound of the pressure regualtor operating. It's more pronounced on some cars than others, though.

jeremy · Unread post by **jeremy** » 01 Apr 2007, 07:48

I think the noise you describe is the pumping process. With a flat accumulator there is no give in the system except metal stretch so the pumping cycle is rapid and short. Its now longer with a good accumulator.

It sounds as though the thing is still cycling too fast which is probably due to wear in the non-return valve under the accumulator sphere. the good news is that this can often be re-seated at no cost. Procedure is remove sphere, remove bolt on accumulator mounting face and collect ball bearing. Stick bearing back in hole and tap it smartly ONCE using a brass punch - and re-assemble.

Must not use a steel punch or you will get a flat on the ball and it will not seal. Must not hit it more than once or you will get overlapping seats- which will not seat.

fangy · Unread post by **fangy** » 01 Apr 2007, 16:48

Thanks for that everyone, I've been spending a bit of money on the car and was a bit worried about this noise. When I got the car the accumulator sphere was flat so I've never heard what it should sound like. I'll invest in a brass punch and re-seat the ball bearing.
Fangy.

jeremy · Unread post by **jeremy** » 01 Apr 2007, 20:42

I did the first one using an old MIG welding nozzle (copper) held on the end of a steel drift with an old Citroen hydraulic seal to hold it on.

I think the bearing is 6mm (and the ball under the pressure release screw is 7mm)