Bleading LHM Syslem

[Sam KS]

G'day there Citrophiles

Rather than hijacking another thread any more i thought i'd start a new one. I'm trying to bead the LHM on a Xantia S2.

I have been undoing the bleed screw after doing some citrobics and sitting on low, get a little hiss as i crack the bolt but nothing after. even leaving the motor running. i have been cracking the nut with the chalk line on it, about 1/4 of a turn. the "stop" light is flashing on the dash with an alarm ringing

am i doing something wrong?

[Xaccers]

When you open the bleed valve the pressure in the system goes, which will be why you're getting the stop light.
Once the whistle stops, the pressure is gone and LHM should be going straight back to the tank so leave it open for a little while and nip it back up.

[addo]

Sam - that's correct.

It's not like bleeding brakes; you don't let the fluid out.

What is happening, is the fluid pressure is being allowed to dissipate through the return hose (at the bottom of that regulator assembly) to the square reservoir. I only let it pass through for a few seconds; five is plenty for me.

Residual pressure in the rear brakes (assuming suspension was set to low when the bleeder was cracked) is released by pressing the brake pedal repeatedly, say 30-40 times. After doing this, have a cuppa or a smoke and all remaining pressure will be exhausted in a conventional system. Hydractives seem to hold pressure in the centre sphere often; later ones have a bleeder screw (like a brake caliper) but early ones don't.

[Sam KS]

i had it open (only 1/4 turn) with motor running for about 15 min, still nothing so came back down to the house to post this. is that still right?

[citronut]

you should only get air coming from this bleed screw,

citroen used to state that after working on/opening the hydraulic system to let the car idle for about two min's with the bleed screw open, then hold the revs at 2.500rpm whilst shutting the bleed screw

[Xaccers]

i had it open (only 1/4 turn) with motor running for about 15 min, still nothing so came back down to the house to post this. is that still right?

No problem at all. As addo said, LHM will just be freely circling from the reservoir to the pump, through the regulator and back to the reservoir until you nip the screw back up.
Never remove the screw unless it is to replace the o ring on it as there is a ball bearing behind that will make a run for it!

[Sam KS]

.....is released by pressing the brake pedal repeatedly, say 30-40 times. ....

sorry i was typing the other reply, so lower it leave motor running, crack bead valve 1/4 turn, pump brakes and then leave motor running?

i am normally mechanically minded and actually work in the motor trade but i think we had about 10 min on these at TAFE (Collage to you Pomgolians) back in 1989 and as the teacher said to us, we'll never have to know about them...... we'll now i do need to and have no idea. (Haynes BOL on order from UK)

[addo]

You normally pump the pedal once it's powered off, but as it's not generating more pressure, I suppose it could be done with engine on.

[Sam KS]

ok, i think it must be ok by now. I run the car, on low with the bleed valve open and leave it of a while but when i look in the tank i cant see any thing happening. should it be?

if that is all good i have another question. i still have a ticking noise when i'm not citrobicing (a new verb there) and my LHM levels are perfect.

[Junkman]

How long is the interval between the ticks? A tick every 5 or so seconds is normal.

[RichardW]

If it's ticking every 5 seconds, the accumulator is FUBAR or there is a substantial internal leak somewhere. Should be 30s +

[Sam KS]

it's every 5 sec. the accumulator is the back part in the above photo?

[Xaccers]

it's every 5 sec. the accumulator is the back part in the above photo?

Just to confirm, is that every 5 seconds with the bleed screw done up?

The accumulator is the big round green thing in the picture above

Ticks with the engine idling, suspension on normal and bleed screw done up should be more than 30 seconds apart.
If the accumulator needs replacing, and your car has anti sink (1995ish onwards) then you have a rear accumulator up behind the spare wheel which is likely to need replacing too.
Do a search on my posts for the trick to it as the pipe goes straight into the back of the sphere, so you need a 9mm flare spanner and a replacement pipe seal.

[Sam KS]

Thanks for that, and yep every 5 seconds when the bleed screw is done up and at normal hight, it looks like it's cactus. i did some searching last night after posting the above comment and found this http://www.frenchcarforum.co.uk/forum/v ... hp?t=24595" onclick="window.open(this.href);return false; so will be having a read this arvo when i get home from work.

I'll try and track down the accumulator and anti sink spheres before the weekend but getting LHM in time could prove tricky. will i do any damage leaving it for a week?