Jogador wrote:So much for a quck and cheap fix...
The bouncy ride is back
Drat! I hate to say it but I'm not surprised, I spent years chasing air bubbles being drawn into the hydraulic system on my previous Xantia and never completely got to the bottom of the problem, I was able to prove conclusively that air bubbles were being sucked into the pump but not where they were coming from.
The result was intermittent harsh/bouncy ride. This type of problem can be very intermittent and seem to be fixed for a while but then return later.
Also, the rear is again starting to shoot up under braking. Once or twice, the rear end even dropped drastically when releasing the brake pedal-this was also the case when I first bought the car and the hydraulics really weren't taken care for (lhm replacement and brake bleeding sorted it right out). There is no frothing in the lhm tank, even when testing with the trick for flushing out air.
My best guess is that the anti-sink membrane is leaking continiously (even more now, since it's been regassed) and the nitrogen is getting into the rear brake circutry (where it can't escape because of the length of rear brake pipes). My only idea, as there's no air bubbles in the lhm tank and this sphere is a reserve for the rear brakes.
Sounds plausible or even possible?
Yes very plausible, I concur with Xac's comments on a ruptured anti-sink sphere.
I've personally seen a ruptured anti-sink sphere on my Dad's Xantia that was bubbling nitrogen into the rear suspension and brake lines constantly.
The rear suspension was shooting right up even under modest braking (always a sign the rear brakes aren't working) so of course I bled the brakes and they worked fine for a while. Just a few weeks later the rear was shooting up again under braking, I bled the brakes, large quantities of "air" came out again and the brakes were fine...a few weeks later it was shooting up at the back again under braking...you get the idea
This went on 3 or 4 times until he had the money to replace the anti-sink sphere, we did one final bleed after that and the problem never came back. The sphere squirted out a steady stream of oil when removed too which is typical for a sphere with a punctured diaphragm. A pretty open and shut case!
As far as I can see this would only affect the rear suspension though, is your "bouncy ride" only at one end of the car or both ?