[frembrit]

Hi all,

When I brake at slow speeds, say in traffic or approaching a junction, the brake pedal has a pulsing sensation coming from it and the braking efficiency drops off a little. Associated with the pulsing pedal is a pulsing/buzzing noise coming from the engine bay (I assume). Any ideas?

It was doing this for a while before I changed my discs and pads and also changing to larger V6 calipers. The brake system has been bled also.

Today, I checked the vacuum pipes from the Servo to the inlet manifold and they look ok. Also pumped the brake pedal until it got hard (ooer!) then started the car and it had the normal give in the pedal.

Can anyone recomend checking anything else? or have you had this problem? I would greatly appriciate any help I can get.

Thanks.

 

[frembrit]

oh, I should have mentioned that it probably happens about 80% of the time. And that braking during other times is fine. e.g: slowing down from 60mph to 30 mph.

 

[Islander]

Sounds like your ABS is being activated. Happened on my old Primera. It was caused by a crack in the ABS ring fitted to the front CV joints. Jack up your car, look at the notched ring on the CV joint and turn the wheel slowly. If you see a crack in the ring that is your problem. If not try the other side. As you are slowing down the ABS sensor detects a longer gap between notches and thinks you are skidding and activates the ABS. I am assuming that the ABS on the Mondeo works in a similar fashion to the Primera. Hope this helps.

 

[frembrit]

Thanks. A fair point. I will have a look at that some time.
But, I thought the ABS did not work below a certain speed on the Mondeos. I could be in 'stop go' traffic and it will do it then too. (again, but not all the time)

 

[RMDrive]

Could it be a suspension problem that is introducing the judder? I have the same problem but I've checked the disks and they are not warped. I have some rattles going on in the front suspension that I hope to have a look at over the Christmas.

 

[frembrit]

Cheers, but it's not brake judder. it's more of a fast pulsing feeling in the brake pedal when the car is going at approx 3-5mph and slowing down to stop. It feels like ABS (though I cant remember what that feels like entirely, as the ABS has not kicked in during my normal driving for a while now).

 

[frembrit]

Sounds like your ABS is being activated. Happened on my old Primera. It was caused by a crack in the ABS ring fitted to the front CV joints.

:L Exactly that. Thanks. :L I finally had some time and took a look at it this morning and found a crack in the near side front ABS ring. The other side is fine. Looks like a new CV joint then.

Also found that both the lower ball joints seem to have a lot of play in them too, so new arms as well then. :sad:

 

[SDR]

isn't it the same sensor detecting that the wheels are spinning and in turn that activates the traction control and breaks to reduce the torque on the spinning wheel? this can happen at very slow speed.