DS7 Brakes

[Iansel]

My rear brake pads and discs are significantly worn according to the garage. Car has only done 22k miles much of it on motorway and still on original tyres.

Apparently the front pads and discs are fine.

Is there a front/rear brake bias adjuster fitted to the DS7 and if so where is it and how do you adjust it?

[GiveMeABreak]

No, that’s a bit old school. They don’t have anything like that on most modern vehicles. Electronic Brake force distribution and other fancy features are all handled by the ESP ECU to ensure maximum even braking efficiency these days.

That’s not unusual mileage nowadays for discs and pads. I’ve just replaced front pads and discs (badly scored) at 16k miles and the rear discs are 60% worn. Further, the rear discs have huge lips on the edge, so they’re will also need replacing soon.

As the electronic handbrake operates the rear brakes, you have to factor in features such as hill start assist and the like. Pulling away with electronic parking brakes will keep the rear brakes applied until you start to move off and then will release. All this extra holding of the rear brakes may likely be the cause of additional wear not usually associated with rear braking.

The materials used may also be a factor these days - softer materials may lead to more frequent replacement.

I’ve dumped the OEM discs and pads and have had some Brembo replacements instead. Much better quality and a third of the price of dealer branded ones. These are also oiled and treated, which it didn’t look like the OEM ones were as they had rusted right through the centre where they join and well down into the honeycombed part. We shall see how long these fare by comparison.

[Iansel]

Marc,

Last time I tried to replace pads on a electrically controlled parking brake I couldn't work out how to release them while parked.

How do you do it on the DS7?

[GiveMeABreak]

Hi Ian, looking at the DS7, these will have electronically operated brake calipers. So there is a motorised unit on each of the rear calipers that acts directly on these. In order to do any maintenance like pads or discs, the rear motorised brake calliper actuator has to be put into the dismantling position using Diagbox.

So it's not an easy job without specialist diagnostic tools unfortunately.

[Iansel]

How to disable the parking brake.


Switch off the engine.
Illumination of the indicator lamps in the
instrument panel and control lever confirm
application of the parking brake.

Switch on the ignition again, without starting
the engine.

Release the parking brake manually by
pushing the control lever while keeping your
foot on the brake pedal.
The complete release of the parking
brake is confirmed by the brake
indicator lamp and the P indicator
lamp in the control lever going off,
accompanied by the display of the
message "Parking brake released".

[GiveMeABreak]

Hi Ian

Be aware that the procedure you have copied from the manual is to just manually release the brake. This may be needed when being towed for example. It will NOT suffice to undertake any maintenance on the braking system such as brake pad or caliper replacement.. For this a diagnostic tool is needed to put the motorised brake calliper actuator in the dismantling position. Then the battery has to be disconnected, to prevent accidental re-application once the ignition is switched on as a precaution.

[Iansel]

Marc,

Thanks. I had sort of worked that out once I got the wheel off and had a good look at the design. Having done so it would appear to be standard Citroen design so at least i shouldn't have to take it to an official DS garage as my closest is 35 miles away.

i have also identified that only one of the four rear pads is badly worn which suggests that the slide mechanism on one side isn't sliding freely so garage can sort this out whilst the caliper is off for the replacement pads.

Ian

[GiveMeABreak]

Indeed, well spotted, that does indicate a problem. Citroen have several designs on these - some vehicles use motorised caliper actuators and others use a motorised cable to apply the pads.

[Iansel]

DS7 2019 is motorised caliper design.

[GiveMeABreak]

Yes, I was just generalising - the C5 X7 and C6 used cables and some Picassos used the caliper actuator design - but yes all DS7s use the motorised calipers.

[RichardW]

You can apparently do the caliper motor type by removing the motor and winding the back of the caliper back in, and then pressing the caliper back in with it off - I was not brave enough to try on our Picasso, but I now have a suitable version of Diagbox to put them in repair position, so will probably do the next change myself.

e.g.