C5 Brake Master Cylinder Help Please
Posted 09 July 2019 - 05:28 PM
How am I supposed to remove the cylinder please.
Posted 10 July 2019 - 10:01 AM
Which car is it ?
If it is the 2001 to 2007 model C5 the Haynes manual makes no mention of a fuse box in the way, just undo the 2 nuts holding it in place and then remove it.
If it is the 2008 on model C5 then the French RTA workshop manual says the fuse box has to be removed first.
Posted 10 July 2019 - 04:11 PM
The fuse box is in the way though, I'm going to try and remove the resovoir off the cylinder to see if that makes a difference.
Posted 10 July 2019 - 04:40 PM
Haynes does start by saying to remove the reservoir. When I need to add brake fluid I find it helps if the fuse box lid is removed and it might also help to remove the air ducting. Haynes gives most of the following.
First syphon out the brake fluid since it holds a lot or you could run it out of a bleed nipple but then you risk getting air in the brakes if you run the level out of the reservoir and then to remove air from the abs pump/valves needs a diagnostic. The filter in the top of the reservoir needs a small screwdriver to lever it out and if you leave it out until after bleeding it makes filling easier/quicker. When you come to refill the reservoir I use a small funnel to avoid spilling fluid.
The fluid level sensor and clutch hose need to be disconnected from the reservoir and if you can keep the end of the hose upwards then air will not get in the clutch hose and not need bleeding. The clutch should be done anyway every 2 years when the brake fluid is changed.
Put rags/tissues under the cylinder to catch spillage of fluid. Release the clip each side of the reservoir/master cylinder and pull the reservoir upwards to release it from the rubber sealing grommets.
Undo the brake line connections on the cylinder, preferably using a split spanner to help avoid rounding off the nuts. If there are sealing washers new ones should be used. Then undo the cylinder mounting nuts and it should now be possible to remove it.
If you can, bleed the cylinder before fully connecting the brake pipes back so air is not put into the brakes.
If you need to bleed the clutch I find it better to suck the fluid through the slave cylinder using a Mityvac pump but you may be able to use a large syringe.