How do I get every last drop of Hydraflush out?

adamskibx · Post by **adamskibx** » 27 Jun 2005, 23:30

Just bought 5 litres of LHM to replace Hydraflush- surely if you just drain and refil it wont replace all the Hyraflush? Im leaving it in low overnight then changing it in the morning- What id like to know is, A; is it a bad thing if a little hydraflush is left, and, B; if so how do I get it all out- surely i'll need to get the spheres off and empty those etc? Regards, Adam

bernie · Post by **bernie** » 27 Jun 2005, 23:40

Hi Adam
When the system is depressurised the majority of the LHM goes back to the tank.
The spheres will be empty of LHM but full of gas.
There will be some LHM in the brake lines, the various pipes, the PR, the steering rack and the pump.
You can bleed the brakes to get fresh LHM in them.
As to the rest I would not worry

JohnT · Post by **JohnT** » 28 Jun 2005, 04:30

The two fluids are compatable, so there is no problem with the residue of the flush oil remaining in the system, working along with the new LHM fluid. I do have a post info on how to bleed the system if you need it?

adamskibx · Post by **adamskibx** » 28 Jun 2005, 05:23

Cheers Bernie and John. I think I know how to bleed the system- The pressure release screw? I was going to bleed both front and back brakes as described in the haynes manual just to get all fluid out of the brake lines and replace with LHM too. Ill get on to it tomorrow.
Regards, Adam

Oscar Too · Post by **Oscar Too** » 28 Jun 2005, 14:16

Adam
Some people deliberatly dilute the LHM with hydraflush in order to keep it moving more freely and reduce clogging of the system. No idea whether it works, but I'm not going to fret about it when I change mine back.
BTW, if you bleed the brakes: soak nipples (no the brake nipples you fool [:)]) in WD40, brush up with a wire brush, and use a ring spanner to undo, as if they snap or disintegrate there is no way of getting them out and you'll need a new caliper. New nipples are apparently available from GSF, but not online. Don't bleed them until you've got LHM back into the system - undo the nipple, press the brake until fresh lhm starts coming out, tighten back up.

czenda · Post by **czenda** » 28 Jun 2005, 14:48

Removing the nipples is terrible job. I tried following methods, with various success:
a) method described by Oscar Too.
b) heating the nipple with a blowtorch until red-hot.
c) drilling out the scale and rust from the hollow of the nipple - helps in delivering penetrating agent from inside side of the nipple
d) hydrochloric acid from hardware store. Dissolves scale (yes, the school-time formula CaCO3 + HCl = CaCl2 + CO2) which is the main reason for sticky nipple. Must be applied in drops only!
I can only recommend hexagonal socket wrench or hex ring spanner, not the one with 12 grooves and certainly not open spanner. They round the nipple head too easily.

Kowalski · Post by **Kowalski** » 28 Jun 2005, 14:55

Hydrochloric acid also reacts with aluminium and steel, i.e. the material that the caliper and nipple are made out of. If you can't get the nipple out of the caliper, I supposed you could try dissolving the caliper off it.

Post by **RichardW** » 28 Jun 2005, 16:06

I got both nipples undone on the rear calipers of my previous Xantia, despite a pretty heavy case of corrosion (I was replacing one of the pipes which had rusted through, to give an idea!). Plenty of Plus Gas (much better than WD-40 as a release agent), heat with blow lamp, cool with Plus Gas, heat, cool, tap gently on the end of the nipple with a soft hammer, use 6 sided spanner, gently tap with the heel of your hand - if it doesn't go easily, back to the heat and cool. They will come, but it takes time!

adamskibx · Post by **adamskibx** » 28 Jun 2005, 23:39

Cheers again- ive changed the fluid and it took almost 5 litres so im happy there only a small amount of Hydraflush in there- need to bleed the brakes now as i think theyve got air in them as I ran the car when the fluid was empty to get the excess fluid pumped out. Now I dont think the back brakes are 100% and its more difficult to judge stopping so its definately air in the brake lines. The power stering has improved no end though-its so light and smooth compared to when it was on hydraflush. That reminds me, when browsing the haynes manual it says that the BX has steering that alters the centering force depending on speed-surely they were just assuming it was the same as the older Citroens with DIRVANI? Mine certainly doesnt have that sort of steering and I didnt think any BX did.

jeremy · Post by **jeremy** » 28 Jun 2005, 23:46

Certainly hasn't got DIR... - Looks a perfectly normal system with the slightly eccentric external ram and of course the lovely FDV which might have hidden uses after all!
Jeremy

ghostrider · Post by **ghostrider** » 29 Jun 2005, 04:54

Deifinitely no VariPower (DIRAVI I think that is the manufacturer's name) pity that, another great Cit idea that has fallen by the wayside, the increased power at low speeds balanced the very much stiffer feel at speed, which always made theCX such a dream to drive at speed, the cable to the centrifugal governor broke on one of mine and it was very very twitchy at high speed with maximum assist
Pete
________
Sex Tube

adamskibx · Post by **adamskibx** » 29 Jun 2005, 06:00

Umm I thought I was right about the BX never having VARIPOWER on any model-think Haynes must just borrow chunks of text from different manuals or something.

Mandrake · Post by **Mandrake** » 29 Jun 2005, 18:27

<blockquote id="quote"><font size="1" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by adamskibx</i>

Umm I thought I was right about the BX never having VARIPOWER on any model-think Haynes must just borrow chunks of text from different manuals or something.
<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">
They certainly do.... from memory in the Haynes Xantia manual it makes more than one reference to the "master cylinder" in the brake system... [:D]
Pretty slack really...
Regards,
Simon

adamskibx · Post by **adamskibx** » 30 Jun 2005, 05:31

Yeah that is rather slack, and if you dont know better it could be very misleading.

Kowalski · Post by **Kowalski** » 30 Jun 2005, 15:18

Variable assistance power steering is pretty common now on lots of makes of cars, another Citroen innovation that was years ahead of its time.