The other week when my son was about to embark on reassembling his series one BX 16V after having the engine rebuilt, he decided at the last minute to turn it into a restoration project at short notice.
Having full access to all the 'plumbing' I suggested we give the hydraulics the once over also. Well, I know this isn't "by the book" but after reading several reports from Citroen owners, I decided in my wisdom to take to the flow divider and pressure regulator in a simple manner; didn't have much choice seeing as how I'm in regional Australia & the bits I'd need to do a proper recon job would be sitting on a shelf at GSF at Heathrow, so I removed both, disconnecting (and carefully marking) all the pipes and poured about 2 or 3 litres of fresh petrol into a clean container. I then washed the outside of both before dropping them into the clean petrol & leaving to soak for about a half hour. Taking a small paint brush (also clean) I flushed out all the holes that the pipes fitted in and shook both in the petrol to agitate it through the entire items; pouring in one side draining out the other etc after which I took an air duster gun on the air compressor and at about 110 psi, blew through the various holes where the fittings went in. After flushing the petrol out of my ears, eyes, nose & throat (why can't they make better tasting petrol?)I then shone a spotlight down each hole to see the filters and other parts were clean and with the pressure regulator, carefully removed the 12mm bleed screw and using a soft metal drift with a recessed end, gave the ball bearing a couple of nice sharp taps and then refitted the 12mm screw. We then refitted both, bled the system after cleaning all the filters and filling with fresh LHM and have a hydraulic system that was a bit lazy prior to the strip down, working absolutely perfect.
This is on a car with 120,000 miles that we bought as a write off after it had an underbonnet fire.
As we often have people asking about cleaning and flushing their systems, I thought I'd share this one with the board as an alternative method.
As I say, it's not as they say to do in the manuals & it may not work for everyone, but it certainly worked for us. Car stays up for days too incidentally.
Alan S
Hydraulics rejuvination
Moderator: RichardW
Alan, I'll ask you one!
When you bleed the hydraulic system on BX, what is your way to do the job properly? What I mean is actually do you bleed the brakes only or do you combine it with opening of that famous 12 mm bolt or is it something else?
It seems to me that my Xantia (and of course me) has problem with air in system. If I do proper citrobics (at least 6 - 7 times up and down) system & brakes are fine for 100 - 150 km. In that case car stays up for almost 5 - 8 hours. I've never bled the brakes by myself. Also I'm not sure if it is needed to bleed the doseur (system on my Xantia is almost similar to BXs).
Other opninions are wellcome!
Thanks
When you bleed the hydraulic system on BX, what is your way to do the job properly? What I mean is actually do you bleed the brakes only or do you combine it with opening of that famous 12 mm bolt or is it something else?
It seems to me that my Xantia (and of course me) has problem with air in system. If I do proper citrobics (at least 6 - 7 times up and down) system & brakes are fine for 100 - 150 km. In that case car stays up for almost 5 - 8 hours. I've never bled the brakes by myself. Also I'm not sure if it is needed to bleed the doseur (system on my Xantia is almost similar to BXs).
Other opninions are wellcome!
Thanks
When I bleed (particularly a car that I haven't done before) I firstly start off by fitting new hose clips at the supply hose on the tank; that way I'm not about to create perpetual motion by sucking air in as fast as I'm pumping it out.
I bled the doseur on my old BX Trs but my current car is a 16V and it's almost impossible to access so to answer your question, I would bleed it if it were easier.
Then set the suspension to the bottom, then to full height and slacken the 12mm bolt. The "hisssss....thump" will be heard. Retighten.
Remove front wheels and set suspension to normal ride height. Fill LHM tank to an overfill level.
Get an assistant in the car to start the engine and fit a piece of clear plastic tube to the bleed nipple. Loosen nipple and with the end of the tube in a clear glass jar, get them to apply the brake pedal. Grotty coloured fluid combined with bubbles will come out. Get them to keep the pressure on the brake pedal until clean fluid without bubbles starts to flow into the jar. At that stage, tighten or shut off the flow whilst the assistant still has pressure on the pedal & the fluid is still flowing out. Repeat on the other front wheel.
Remove one rear wheel and under the arm or the disc rotor, get a jack and apply upward pressure so as to make the rear suspension imagine it's on the road with the weight of the car on it. Bleed as with the front using the clear plastic tube & jar. Keep an eye at all times on the level of LHM in the tank as it's possible to use a litre up very quickly. Refit the road wheel and move to the other rear wheel & repeat the procedure there.
When concluded, do the Citaerobics but loosen the 12mm bleed screw, let the air escape, then retighten at the end of each time you set to highest setting.
Reset the car to normal ride height and leave sit for a half hour before rechecking the level in the LHM tank. This gives it time for all the froth that is usually in the tank to settle and gives a more accurate assessment of fluid level. If slightly overfilled, don't worry. To check level, I don't even look at the gauge shown on the tank; I stick my finger in & if it comes out with the nail wet with LHM, I reckon that's about spot on.
Alan S
I bled the doseur on my old BX Trs but my current car is a 16V and it's almost impossible to access so to answer your question, I would bleed it if it were easier.
Then set the suspension to the bottom, then to full height and slacken the 12mm bolt. The "hisssss....thump" will be heard. Retighten.
Remove front wheels and set suspension to normal ride height. Fill LHM tank to an overfill level.
Get an assistant in the car to start the engine and fit a piece of clear plastic tube to the bleed nipple. Loosen nipple and with the end of the tube in a clear glass jar, get them to apply the brake pedal. Grotty coloured fluid combined with bubbles will come out. Get them to keep the pressure on the brake pedal until clean fluid without bubbles starts to flow into the jar. At that stage, tighten or shut off the flow whilst the assistant still has pressure on the pedal & the fluid is still flowing out. Repeat on the other front wheel.
Remove one rear wheel and under the arm or the disc rotor, get a jack and apply upward pressure so as to make the rear suspension imagine it's on the road with the weight of the car on it. Bleed as with the front using the clear plastic tube & jar. Keep an eye at all times on the level of LHM in the tank as it's possible to use a litre up very quickly. Refit the road wheel and move to the other rear wheel & repeat the procedure there.
When concluded, do the Citaerobics but loosen the 12mm bleed screw, let the air escape, then retighten at the end of each time you set to highest setting.
Reset the car to normal ride height and leave sit for a half hour before rechecking the level in the LHM tank. This gives it time for all the froth that is usually in the tank to settle and gives a more accurate assessment of fluid level. If slightly overfilled, don't worry. To check level, I don't even look at the gauge shown on the tank; I stick my finger in & if it comes out with the nail wet with LHM, I reckon that's about spot on.
Alan S