Technical 2012 1.3 multijet slave cylinder

[lockpicker1969]

Hi

I am new to the forum and this is my first post.
I have a 2012 1.3 multijet

I noticed that my slave cylinder has been leaking fluid so I have bought a new one. I have read that it is best to remove battery and battery tray holder for access which I am ok doing. I am ok fitting the new slave but what I am unsure about is how to bleed the system afterwards. I have noticed that the fluid in the holder is dirty so I would like to flush out and replace it all. Does anyone know how much fluid this will take and how to bleed the system.

Kind regards

Richard

 

[bugsymike]

Hi

I am new to the forum and this is my first post.
I have a 2012 1.3 multijet

I noticed that my slave cylinder has been leaking fluid so I have bought a new one. I have read that it is best to remove battery and battery tray holder for access which I am ok doing. I am ok fitting the new slave but what I am unsure about is how to bleed the system afterwards. I have noticed that the fluid in the holder is dirty so I would like to flush out and replace it all. Does anyone know how much fluid this will take and how to bleed the system.

Kind regards

Richard

Remember the "holder" is the brake fluid reservoir also, so probably best not to disturb it too much.
A 500ml bottle of brake fluid Dot 4 spec should be enough.
If you are lucky, personally I have bled cylinders by removing the bleeder on the slave and keep topping the reservoir up until clean fluid with no air bubbles comes out the slave cylinder just using gravity and then carefully nipping up the bleeder.
Normal process however is to have one person press the clutch pedal down and hold it down as the bleeder valve is opened and once air/fluid has come out nip up the bleeder, only then should the person on the clutch pedal bring the pedal slowly up. This process will need to be repeated several times until all air removed/no bubbles in the clean fluid coming out .
Note if the pedal pusher doesn't follow those instructions 100% the job will not be done. My ten year old daughters were more obedient in following this than my ex wife!
There are various bleeding devices available to purchase, both vacuum and pressure types. I have found the pressure ones best, but others prefer vacuum. Either way the instructions need to be followed precisely.
I have just fitted a s/h gearbox on a 2014 1.3 mj Vauxhall Combo/Fiat Doblo, you will note there is a gearbox extra support bar in the way of the clutch cylinder and also different length bolts and spacers you need to refit correctly, but nothing too technical.
If you accidentally drain the reservoir when bleeding, although not a good idea as the job will take much longer bleeding the master as well as the slave cylinders, it shouldn't affect the brakes as if you look at where the clutch master cylinder is fed from the combined reservoir, the clutch pipe is higher than the brake ones.
The reason is if you were to have a clutch hydraulic failure, then the brakes would still have fluid to work.

 

[lockpicker1969]

Thank you for your quick reply.

I had read somewhere that you had to undo the plastic nut half a turn, pump the pedal and hold down, nip the nut and then repeat until the air is out. This was how I did my Vauxhall vivaro which was a real pain to do when the brake cylinder and bracket broke.

After inspection of the new slave cylinder, I realised that I don’t have the plastic nut/block off valve. I just have a rubber cover. Could I attach some clear hose to this and hold my finger over the hose in between each depress?

I will get some Dot4 and give this a go next week.

 

[bugsymike]

Thank you for your quick reply.

I had read somewhere that you had to undo the plastic nut half a turn, pump the pedal and hold down, nip the nut and then repeat until the air is out. This was how I did my Vauxhall vivaro which was a real pain to do when the brake cylinder and bracket broke.

After inspection of the new slave cylinder, I realised that I don’t have the plastic nut/block off valve. I just have a rubber cover. Could I attach some clear hose to this and hold my finger over the hose in between each depress?

I will get some Dot4 and give this a go next week.

I expect there is a bleed valve/nut under the rubber cover and as you say holding your finger over the hole can work as a simple one way valve.
However often vigorous pumping introduces air into the system, making the job take longer, especially on older vehicles as the master cylinders age.
At the end of the day try what works best for you from previous experience.

 

[lockpicker1969]

There is no bleed valve nut under the rubber cover

 

[bugsymike]

There is no bleed valve nut under the rubber cover

I have just checked on the spare one I kept from the old gearbox.
What it looks like is the circlip has to be pulled out so the hose is eased back enough to uncover the bleed section under that rubber cap as in my photos. Apologies for the poor photo quality, shaky 72 year old with old camera.

 

[woolfie]

I have just checked on the spare one I kept from the old gearbox.
What it looks like is the circlip has to be pulled out so the hose is eased back enough to uncover the bleed section under that rubber cap as in my photos. Apologies for the poor photo quality, shaky 72 year old with old camera

 

[woolfie]

Just replaced the slave cylinder in mine 2006 doblo , as said above pull the clip and draw the hose back I would advise a piece of tubing attached into a jar with a little brake fluid to stop a jet of fluid hitting you in the face . Also stops air getting back into the system. If this doesn't work leave the car jacked up on passenger side with the hose pulled back and let nature take its course with the air finding it's way out to the highest point. Good luck it took me 2 days to bleed mine and I've done this before on the dobber .

 

[bugsymike]

Alternatively as @woolfie suggests, but before mounting cylinder on gearbox do the gravity bleed, but holding cylinder in a position that the air is helped out of the cylinder.
Note keep people away from the pedal when doing this or the piston will get shoved out of cylinder.